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TDMS Study 05210-04 Pathology Tables

NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38

                                                           CORE STUDY




       Facility:  I. I. T. Research Institute

       Chemical CAS #:  100-41-4

       Lock Date:  10/02/92

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































                                                              Page   1

NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 5| 6| 7| 5| 7| 7| 7| 7| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 2| 3| 8| 3| 3| 3| 6| 3| 1| 7| 3| 3| 3| 3| 3| 2| 3| 9|             
                                           | 1| 1| 2| 2| 1| 0| 2| 5| 1| 8| 1| 1| 2| 5| 9| 5| 8| 1| 1| 2| 0| 1| 9| 2| 7|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | M  +  +  +  +  +  +  +  +  A  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  M  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                              2                 2         |             
      Clear Cell Focus                     |                                                                          |             
      Eosinophilic Focus                   |                                                                      2   |             
      Infiltration Cellular                |    2           2                                   2                     |             
      Inflammation                         |                                                       1                  |             
      Necrosis                             |                                                                          |             
      Pigmentation, Hemosiderin            |          2                                                               |             
      Hepatocyte, Vacuolization Cytoplasmic|                2                                                         |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                     +                                    |             
      Fat, Necrosis                        |                                     3                                    |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                  1  2                 1        1         |             
      Acinus, Hyperplasia                  |                                                                         1|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |    1  1  1     2     2  1     2  1  2  1     1     1  1  1  1  2         |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                                          |             
      Glands, Cyst                         |                                                                1         |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                   1  1        1                    1                    1|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +|             
      Accessory Adrenal Cortical Nodule    |                                                                          |             
      Degeneration                         |    3  1                       1                             1        2   |             
      Hemorrhage                           |             2                                                            |             
      Hyperplasia                          |          1                       2                                       |             
      Necrosis                             |                                                                         3|             
      Vacuolization Cytoplasmic            |                3                                                         |             
      Capsule, Hyperplasia                 | 2  2  2  2  1  1  3  2  1  2  2  3  3  2  1     2  2  2  2  2  3     2  3|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   2                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 5| 6| 7| 5| 7| 7| 7| 7| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 2| 3| 8| 3| 3| 3| 6| 3| 1| 7| 3| 3| 3| 3| 3| 2| 3| 9|             
                                           | 1| 1| 2| 2| 1| 0| 2| 5| 1| 8| 1| 1| 2| 5| 9| 5| 8| 1| 1| 2| 0| 1| 9| 2| 7|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +|             
      Hemorrhage                           |                            2                                             |             
      Hyperplasia                          |                                     2  2                                 |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  M  M  +  M  M  +  M  M  +  +  M  M  +  +  +  M  +  +  M  +  M  M  M  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  M  +  +|             
      Pars Distalis, Hemorrhage            |                               3                                          |             
      Pars Distalis, Hyperplasia           |          2        1              1                             1         |             
      Pars Intermedia, Hyperplasia         |                               3                                4         |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicle, Degeneration               |                                                                   1      |             
      Follicular Cell, Hyperplasia         | 1  2  1        3  1     1     1  1                          1            |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                        +                                 |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  M  M  +  +  M  +  +  +  +  M  +  M  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                          1               |             
      Cyst                                 |                1        1                       2  4                     |             
      Hemorrhage                           |                               1                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                                        3                                 |             
      Inflammation                         |                                                                          |             
      Endometrium, Hyperplasia             | 3  3  2  3  2  3  3  3  4  2  4  4  3     3  2  3  3     3  3  2     3  3|             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                 +                        |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                                                2         |             
      Pigmentation, Hemosiderin            |                                                 2        1               |             
      Myeloid Cell, Hyperplasia            |                                        2                                 |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                                 +                       +|             
      Inguinal, Pigmentation, Hemosiderin  |                                                                         2|             
      Lumbar, Hyperplasia                  |                                                 2                        |             
      Renal, Hyperplasia                   |                                                 2                        |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  M  M  +  +  +  M  +  +  +  +  +  M  M  +  M  +  M  M  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hyperplasia                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   3                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 5| 6| 7| 5| 7| 7| 7| 7| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 2| 3| 8| 3| 3| 3| 6| 3| 1| 7| 3| 3| 3| 3| 3| 2| 3| 9|             
                                           | 1| 1| 2| 2| 1| 0| 2| 5| 1| 8| 1| 1| 2| 5| 9| 5| 8| 1| 1| 2| 0| 1| 9| 2| 7|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Inflammation, Granulomatous          |                                                                      4   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  M  +  M  +  +  M  +  M  M  +  +  +  M  +  +  M  M  +  M|             
      Hyperplasia, Histiocytic             |             2                                                            |             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |             2              2        1                                    |             
      Hyperplasia                          |                                                                          |             
      Pigmentation, Hemosiderin            |                2     1                                               2   |             
      Lymphoid Follicle, Hyperplasia       |                2  2                 2                                    |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  M  +  +  +  +  M  +  +  +  +  +  M  M  +  +  +  +  +  M  +  M|             
      Atrophy                              |                                        3  3                              |             
      Thymocyte, Hyperplasia               |                                     2                                    |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                                                         2|             
      Necrosis                             |                                                                          |             
      Ulcer                                |                                                                   2      |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Periosteum, Femur, Inflammation      |                                                                      2   |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Mineralization                       | 1              1  1  1  1  1                       1     1               |             
      Cerebellum, Atrophy                  |                      2                                                   |             
      Cerebrum, Atrophy                    |                                                                          |             
      Medulla, Atrophy                     |                      2                                                   |             
      Medulla, Hemorrhage                  |                                                                         2|             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                         +|             
      Hemorrhage                           |                                                                         3|             
      Myelin, Degeneration                 |                                                                         1|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                 1                        |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Infiltration Cellular, Histiocyte    |                                                                      2   |             
      Vein, Thrombosis                     |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   4                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 5| 6| 7| 5| 7| 7| 7| 7| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 2| 3| 8| 3| 3| 3| 6| 3| 1| 7| 3| 3| 3| 3| 3| 2| 3| 9|             
                                           | 1| 1| 2| 2| 1| 0| 2| 5| 1| 8| 1| 1| 2| 5| 9| 5| 8| 1| 1| 2| 0| 1| 9| 2| 7|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Hemorrhage                           |                                                       2                  |             
      Inflammation                         |          1                                                               |             
      Nasolacrimal Duct, Inflammation      |             2                                                            |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |          2                                                               |             
                                            __________________________________________________________________________|             
   Pleura                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                           +                              |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Casts Protein                        |                                                                      1   |             
      Nephropathy                          |                   1           1     1  2        1        1              1|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
      Hemorrhage                           |                                        3                                 |             
      Infiltration Cellular                |          2     2                                      2                  |             
      Inflammation                         |                                           1                              |             
      Ulcer                                |                                        2                                 |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   5                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 2| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 5| 7| 6| 7| 7| 4| 7| 6| 7|            |
                             DAY ON TEST   | 3| 1| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 9| 3| 1| 3| 3| 2| 3| 9| 3|            |
                                           | 0| 8| 1| 0| 5| 2| 1| 2| 1| 1| 1| 2| 2| 1| 1| 2| 2| 1| 8| 0| 2| 3| 2| 4| 2|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    CONTROL                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  A  M  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  44        |
      Infiltration Cellular                |                   2                                                      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  A  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                                                             1            |      3  1.7|
      Clear Cell Focus                     |                                     1                                    |      1  1.0|
      Eosinophilic Focus                   | 2     2        2  1                                                      |      5  1.8|
      Infiltration Cellular                |                                                                          |      3  2.0|
      Inflammation                         |                                                                          |      1  1.0|
      Necrosis                             |                                                       1                  |      1  1.0|
      Pigmentation, Hemosiderin            |                                                                          |      1  2.0|
      Hepatocyte, Vacuolization Cytoplasmic|                                           4                              |      2  3.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               | +                                                                        |   2        |
      Fat, Necrosis                        | 3                                                                        |      2  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |    1              1              3                                       |      7  1.4|
      Acinus, Hyperplasia                  |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                | 1  2                 1  2  1  1  2     1  1        1  1  1  2     2      |     30  1.3|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |                         1                                                |      1  1.0|
      Glands, Cyst                         |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |    1              1  1        2                          1               |     10  1.1|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Accessory Adrenal Cortical Nodule    |                            1              1                              |      2  1.0|
      Degeneration                         |       1        2  1     2     2  2                                      2|     12  1.7|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   6                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 2| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 5| 7| 6| 7| 7| 4| 7| 6| 7|            |
                             DAY ON TEST   | 3| 1| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 9| 3| 1| 3| 3| 2| 3| 9| 3|            |
                                           | 0| 8| 1| 0| 5| 2| 1| 2| 1| 1| 1| 2| 2| 1| 1| 2| 2| 1| 8| 0| 2| 3| 2| 4| 2|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    CONTROL                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Hemorrhage                           |    2                                                                     |      2  2.0|
      Hyperplasia                          |                         1                                                |      3  1.3|
      Necrosis                             |                                                                          |      1  3.0|
      Vacuolization Cytoplasmic            |                                                                          |      1  3.0|
      Capsule, Hyperplasia                 | 2  2  2  1     2  2  2  3  2  3  3  2  1  2  1  2  1  2  2  2     2  2  2|     46  2.0|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Hyperplasia                          |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |                         3                                                |      1  3.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  M  +  +  M  +  +  M  M  M  +  +  M  M  M  +  M  +  M  +  +  +  +  +|  26        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Pars Distalis, Hemorrhage            |                                     2              2                     |      3  2.3|
      Pars Distalis, Hyperplasia           | 1                       2  2        1              1                 2   |     10  1.4|
      Pars Intermedia, Hyperplasia         |                                                                          |      2  3.5|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicle, Degeneration               |                                                                          |      1  1.0|
      Follicular Cell, Hyperplasia         |    3     1           1  2     1     1                    1  1           3|     18  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +|  41        |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Angiectasis                          |       3                                                                  |      2  2.0|
      Cyst                                 |       3  1                       2                                   2   |      8  2.0|
      Hemorrhage                           |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration                         |                               2                                          |      2  2.5|
      Inflammation                         |                               2              1                       2   |      3  1.7|
      Endometrium, Hyperplasia             | 3     3  4     3  3  3  3  2  2  3  2  4  2  4  3  3  2  3  3     3  2  2|     44  2.9|
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Inflammation                         |                                                                          |      1  2.0|
      Pigmentation, Hemosiderin            |                2                                                         |      3  1.7|
      Myeloid Cell, Hyperplasia            |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   7                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 2| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 5| 7| 6| 7| 7| 4| 7| 6| 7|            |
                             DAY ON TEST   | 3| 1| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 9| 3| 1| 3| 3| 2| 3| 9| 3|            |
                                           | 0| 8| 1| 0| 5| 2| 1| 2| 1| 1| 1| 2| 2| 1| 1| 2| 2| 1| 8| 0| 2| 3| 2| 4| 2|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    CONTROL                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                                +         |   3        |
      Inguinal, Pigmentation, Hemosiderin  |                                                                          |      1  2.0|
      Lumbar, Hyperplasia                  |                                                                          |      1  2.0|
      Renal, Hyperplasia                   |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  +  +  +  M  M  M  +  +  +  +  +  +  +  M  +  +  M  +  M  +  +  M  M  M|  32        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  47        |
      Hyperplasia                          |                      3                                                   |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hematopoietic Cell Proliferation     |    2                                                                     |      1  2.0|
      Hyperplasia                          |                      2  2        3     2                                 |      4  2.3|
      Inflammation, Granulomatous          |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  M  +  +  +  +  +  M  +  +  M  +  M  M  M  +  M  +  +  +  +  +|  34        |
      Hyperplasia, Histiocytic             |                                                                          |      1  2.0|
      Hyperplasia                          |                      3  2           2                                    |      3  2.3|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |    2                                                                     |      4  1.8|
      Hyperplasia                          |       3                                                                  |      1  3.0|
      Pigmentation, Hemosiderin            |                                                                         1|      4  1.5|
      Lymphoid Follicle, Hyperplasia       |          4           2           3     3     2        2                  |      9  2.4|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  42        |
      Atrophy                              |                                                 3                    2  2|      5  2.6|
      Thymocyte, Hyperplasia               |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |                                                                          |      1  2.0|
      Necrosis                             |                               2                                          |      1  2.0|
      Ulcer                                |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Periosteum, Femur, Inflammation      |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                 2     1                  |      2  1.5|
      Mineralization                       |       1        1  1     1  1     1     1        1        1        1     1|     19  1.0|
      Cerebellum, Atrophy                  |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   8                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 2| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 5| 7| 6| 7| 7| 4| 7| 6| 7|            |
                             DAY ON TEST   | 3| 1| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 9| 3| 1| 3| 3| 2| 3| 9| 3|            |
                                           | 0| 8| 1| 0| 5| 2| 1| 2| 1| 1| 1| 2| 2| 1| 1| 2| 2| 1| 8| 0| 2| 3| 2| 4| 2|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    CONTROL                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 NERVOUS SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Cerebrum, Atrophy                    |                                                             2           2|      2  2.0|
      Medulla, Atrophy                     |                                                                          |      1  2.0|
      Medulla, Hemorrhage                  |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   1        |
      Hemorrhage                           |                                                                          |      1  3.0|
      Myelin, Degeneration                 |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular                |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                       1                  |      1  1.0|
      Infiltration Cellular, Histiocyte    |                                                                          |      1  2.0|
      Vein, Thrombosis                     |    3                                                                     |      1  3.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Inflammation                         |                                           2              1               |      3  1.3|
      Nasolacrimal Duct, Inflammation      |                                                                          |      1  2.0|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |                                           3                              |      2  2.5|
                                            __________________________________________________________________________|____________|
   Pleura                                  |    +                                                                     |   1        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Casts Protein                        |                                                                          |      1  1.0|
      Nephropathy                          |                1     1  1           1  1                 1               |     13  1.1|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +|  47        |
      Hemorrhage                           |                                                                          |      1  3.0|
      Infiltration Cellular                |                                                          2               |      4  2.0|
      Inflammation                         |                                                                          |      1  1.0|
      Ulcer                                |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   9                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 3| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 0| 9| 3| 9| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3| 3| 3|             
                                           | 1| 0| 5| 1| 0| 2| 1| 2| 2| 0| 2| 2| 2| 2| 2| 1| 3| 2| 1| 1| 0| 1| 2| 1| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | M  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  A  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  A  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  A  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Peyer's Patch, Hyperplasia           |          3                                                               |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                              2                           |             
      Eosinophilic Focus                   | 2        1        1  1                                                   |             
      Inflammation                         |                         1  2                                             |             
      Necrosis                             |                         1  2                    1                        |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Hepatocyte, Necrosis                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                             2            |             
      Atrophy                              |                                                 3           1            |             
      Cyst                                 |                                                 4                        |             
      Degeneration                         |                                                                          |             
      Fibrosis                             |                                                 3                        |             
      Infiltration Cellular                |                   2  1                    2     3                 2  2  2|             
      Necrosis                             |             3                                                            |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                         1                                                |             
      Infiltration Cellular                | 2              1  1  2  1  1     2     2           1        1     1  2  1|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Cardiomyopathy                       | 1        1        1  1  1     2  1     1     1     1  1        1  1      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Adrenal Cortical Nodule    |                                                                          |             
      Degeneration                         |          2     1                                            1            |             
      Hemorrhage                           |                               2                                          |             
      Hyperplasia                          |                      2                                                   |             
      Infiltration Cellular                |                                                                          |             
      Inflammation                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  10                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 3| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 0| 9| 3| 9| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3| 3| 3|             
                                           | 1| 0| 5| 1| 0| 2| 1| 2| 2| 0| 2| 2| 2| 2| 2| 1| 3| 2| 1| 1| 0| 1| 2| 1| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Capsule, Hyperplasia                 | 2  1  3     3  2  2  2  2  1  2  2  1  1  2  2  2  1  1  2  2  2  1  2  1|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                              2                           |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                           1                       2      |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  +  +  M  +  +  +  +  M  M  +  +  +  M  M  +  +  M  M  +  +  M  +  M  +|             
      Infiltration Cellular                |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Cyst                  |                                                          2               |             
      Pars Distalis, Hyperplasia           | 2        2     3                    1  1     3     2                    2|             
      Pars Intermedia, Hyperplasia         |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         |          3  2     1  2     1           1     3              1     1     1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              | +           +                    +                                      +|             
      Fat, Necrosis                        | 2           3                    2                                       |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  M  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                          1               |             
      Atrophy                              |       4                                                                  |             
      Cyst                                 |                                                                      1  2|             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                               2                                          |             
      Endometrium, Hyperplasia             | 4        3  2  3  4  4  4  4  2  4  4  4     4  2  4  4  4  2  3  4  2  3|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |       4                                                                  |             
      Pigmentation, Hemosiderin            |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +                                +              +           +            |             
      Iliac, Hyperplasia                   | 2                                                                        |             
      Lumbar, Hyperplasia                  | 2                                                           3            |             
      Renal, Necrosis                      |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  M  +  +  +  +  M|             
      Hyperplasia                          |                      2                                                   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                      3                                                   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                      2                                                   |             
      Inflammation, Granulomatous          |                                              4                           |             
      Inflammation                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  11                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 3| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 0| 9| 3| 9| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3| 3| 3|             
                                           | 1| 0| 5| 1| 0| 2| 1| 2| 2| 0| 2| 2| 2| 2| 2| 1| 3| 2| 1| 1| 0| 1| 2| 1| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  M  +  M  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                      3                       3                          4|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |       4  4                                      2           2            |             
      Necrosis                             |             3                                                            |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Lymphoid Follicle, Hyperplasia       |                   4  3                                            2      |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |       4     3                                   4                        |             
      Thymocyte, Hyperplasia               |                                                                         3|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                                  2                                       |             
      Hyperplasia                          |                                  2                                       |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fracture                             |          2              2                                                |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |          1     1     1           1  1           1                 1  1   |             
      Cerebrum, Atrophy                    |                                                                      2   |             
      Meninges, Infiltration Cellular      | 1                                         1                              |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Glands, Degeneration                 | 1                                                                        |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                                                    2                     |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  12                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 3| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 0| 9| 3| 9| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3| 3| 3|             
                                           | 1| 0| 5| 1| 0| 2| 1| 2| 2| 0| 2| 2| 2| 2| 2| 1| 3| 2| 1| 1| 0| 1| 2| 1| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Infiltration Cellular                |                                                                          |             
      Nephropathy                          |             2  1              3                                         1|             
      Cortex, Metaplasia, Osseous          |                                                                          |             
                                            __________________________________________________________________________|             
   Ureter                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  M  +|             
      Infiltration Cellular                |                   1              1        1                              |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  13                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 9| 2| 3| 3| 6| 8| 3| 3| 3| 3| 3| 3| 3| 4| 3| 3| 3| 3|            |
                                           | 1| 0| 7| 2| 2| 2| 2| 7| 3| 1| 1| 2| 4| 1| 2| 2| 2| 1| 9| 1| 2| 2| 1| 1| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    75 PPM                                 | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  A  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Peyer's Patch, Hyperplasia           |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  2.0|
      Eosinophilic Focus                   |          2                                               1        2      |      7  1.4|
      Inflammation                         |                                                    2                     |      3  1.7|
      Necrosis                             |                         2                                                |      4  1.5|
      Pigmentation, Hemosiderin            |                2                                                         |      1  2.0|
      Hepatocyte, Necrosis                 |                                                    1                     |      1  1.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  2.0|
      Atrophy                              |                                                                          |      2  2.0|
      Cyst                                 |                                                                          |      1  4.0|
      Degeneration                         |                                           1                              |      1  1.0|
      Fibrosis                             |                                                                          |      1  3.0|
      Infiltration Cellular                | 2  1                                   1     1     2                     |     12  1.8|
      Necrosis                             |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  1.0|
      Infiltration Cellular                | 2  2     1  1  2  1     1  1  2  2        1  1  1  2  1     1  1     2  1|     32  1.4|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Epithelium, Hyperplasia              |          2                                                  1            |      2  1.5|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cardiomyopathy                       | 1        1  1        1  1                 1  1        1     2  1         |     23  1.1|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Accessory Adrenal Cortical Nodule    |          1                                                               |      1  1.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  14                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 9| 2| 3| 3| 6| 8| 3| 3| 3| 3| 3| 3| 3| 4| 3| 3| 3| 3|            |
                                           | 1| 0| 7| 2| 2| 2| 2| 7| 3| 1| 1| 2| 4| 1| 2| 2| 2| 1| 9| 1| 2| 2| 1| 1| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    75 PPM                                 | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Degeneration                         |                                                       1                  |      4  1.3|
      Hemorrhage                           |                                                                          |      1  2.0|
      Hyperplasia                          |             1                          1                          2  1   |      5  1.4|
      Infiltration Cellular                |                               1                                      1   |      2  1.0|
      Inflammation                         |                         2                          2        2            |      3  2.0|
      Capsule, Hyperplasia                 | 2  1  2  1  2  1  1  2  2  2  2  2  2  2  2  1  1  2  2  1  3  2  3  2  3|     49  1.8|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |       2                                                              1   |      3  1.7|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      2  1.5|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  M  M  M  M  M  +  +  M  +  M  +  M  +  M  M  +  +  +  +  M  M  M  M  M|  24        |
      Infiltration Cellular                |                                                 2                        |      1  2.0|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Cyst                  |                                                                          |      1  2.0|
      Pars Distalis, Hyperplasia           |          2                 2              2                       2      |     12  2.0|
      Pars Intermedia, Hyperplasia         |                         2                                                |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         | 1  1     2     1  1  1  1     1        2  2              1  1           1|     23  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                  +                 +                     |   6        |
      Fat, Necrosis                        |                                                    3                     |      4  2.5|
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  1.0|
      Atrophy                              |                                                                          |      1  4.0|
      Cyst                                 |                   2     2  2        3                 4           1      |      8  2.1|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration                         |                                                                          |      1  2.0|
      Endometrium, Hyperplasia             | 3  4  2  3  3  3  4  3  2  2  2  3     4  3  4  4  4  1  3  3  3  3  3  3|     46  3.2|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                                                                          |      1  4.0|
      Pigmentation, Hemosiderin            |                                  3                                       |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                  +  +                 +                  |   7        |
      Iliac, Hyperplasia                   |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  15                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 9| 2| 3| 3| 6| 8| 3| 3| 3| 3| 3| 3| 3| 4| 3| 3| 3| 3|            |
                                           | 1| 0| 7| 2| 2| 2| 2| 7| 3| 1| 1| 2| 4| 1| 2| 2| 2| 1| 9| 1| 2| 2| 1| 1| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    75 PPM                                 | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Lumbar, Hyperplasia                  |                                                                          |      2  2.5|
      Renal, Necrosis                      |                                                       3                  |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  M  M  +  +  M  +  M  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  40        |
      Hyperplasia                          |                                                                   2      |      2  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia                          |          2                                                               |      2  2.5|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia                          |                         3                                         2      |      3  2.3|
      Inflammation, Granulomatous          |                                                                          |      1  4.0|
      Inflammation                         |                         2                          3                     |      2  2.5|
      Necrosis                             |                                                       3                  |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  M  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|  42        |
      Hyperplasia                          |                                                                   2      |      4  3.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                         2                          4        3            |      7  3.0|
      Necrosis                             |                                                                          |      1  3.0|
      Pigmentation, Hemosiderin            |                                                          2               |      1  2.0|
      Lymphoid Follicle, Hyperplasia       |                                  2                                2      |      5  2.6|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  M  +  M  +  +  +  +|  44        |
      Atrophy                              |       3                 3                                                |      5  3.4|
      Thymocyte, Hyperplasia               |                            2                                             |      2  2.5|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |                                                                          |      1  2.0|
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Fracture                             |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                      +  +                                                |   2        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       | 1                       1              1     1     1  1  1  1     1      |     17  1.0|
      Cerebrum, Atrophy                    |                                                                          |      1  2.0|
      Meninges, Infiltration Cellular      |                                                                          |      2  1.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  16                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 9| 2| 3| 3| 6| 8| 3| 3| 3| 3| 3| 3| 3| 4| 3| 3| 3| 3|            |
                                           | 1| 0| 7| 2| 2| 2| 2| 7| 3| 1| 1| 2| 4| 1| 2| 2| 2| 1| 9| 1| 2| 2| 1| 1| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    75 PPM                                 | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Glands, Degeneration                 |                         1                                                |      2  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia, Lymphoid                |                                                                      2   |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |                                                    2                    1|      2  1.5|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |                   4                                                      |      1  4.0|
      Nephropathy                          |                                           1  1        2                  |      7  1.6|
      Cortex, Metaplasia, Osseous          |                                                    1                     |      1  1.0|
                                            __________________________________________________________________________|____________|
   Ureter                                  |                                                       +                  |   1        |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Infiltration Cellular                |                                  2                                       |      4  1.3|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  17                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7| 0| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 3| 8| 3|             
                                           | 1| 1| 2| 2| 1| 1| 2| 1| 1| 6| 2| 2| 2| 2| 1| 2| 1| 6| 1| 2| 1| 0| 0| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    250                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  M  +  M  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                         2        2                                       |             
      Clear Cell Focus                     |                                                                          |             
      Eosinophilic Focus                   |          2           2           1  1                                    |             
      Hemorrhage                           |                                                                          |             
      Hepatodiaphragmatic Nodule           |                                                                          |             
      Inflammation                         |                                     1                                    |             
      Mixed Cell Focus                     |                      3                                                   |             
      Necrosis                             |                                     1                                2   |             
      Hepatocyte, Syncytial Alteration     |                      1                                                   |             
      Hepatocyte, Vacuolization Cytoplasmic|                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |    1     2     2  1  2        2  2                             1         |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                | 1  2  1  2  1  1     2        2  2  2     1           2  1     2  1  1   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |          1  1  1     1     2  2        2  1           1  1  1     1     2|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                   1                 1  2                                 |             
      Hemorrhage                           |                                                                          |             
      Hyperplasia                          |                                                             1            |             
      Capsule, Hyperplasia                 | 1  2  2  2  2  1  2  2  2  2  2  2  2  2  1  2  2     2  2  2  2  3  2  2|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
      Infiltration Cellular                |                         2                                                |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  M  +  +  M  +  +  M  +  +  M  +  +  +  M  +  +  +  +  +  M  M  +  M  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  18                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7| 0| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 3| 8| 3|             
                                           | 1| 1| 2| 2| 1| 1| 2| 1| 1| 6| 2| 2| 2| 2| 1| 2| 1| 6| 1| 2| 1| 0| 0| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    250                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Pars Distalis, Angiectasis           |                   2                    3                                 |             
      Pars Distalis, Hemorrhage            |                                                                          |             
      Pars Distalis, Hyperplasia           | 3  2     2     2     3  2        2  2        2        2  1        2      |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                       1                  |             
      Follicular Cell, Hyperplasia         |    1        2     1  1        2  2  1        2        1     1  1        1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                            +                             +  +  +         |             
      Fat, Necrosis                        |                                                          1  2  2         |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                            3                                             |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Cyst                                 |             3                                2  2        2               |             
      Hemorrhage                           |                                                                          |             
      Infiltration Cellular                |                      2        3                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                 2                        |             
      Hemorrhage                           |                                                                          |             
      Thrombosis                           |                                                             2            |             
      Endometrium, Hyperplasia             | 3  3  4  3  3  4  3  4  3     2  3  3  2  3  2  3     3  2  3  3  2  2  2|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pigmentation, Hemosiderin            |                               2                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                                                         +|             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  M  +  +  M  M  M  M  M  +  +  M  +  +  +  M  M  +  M  +  +  +  M  +  M|             
      Hyperplasia                          |                                                             2            |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +|             
      Hyperplasia                          |                   2  3        3                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  M  +  +  +  +  +  M  +  +  +  +  +  +  M  M  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                            3                                             |             
      Pigmentation, Hemosiderin            |                                                 1                        |             
      Lymphoid Follicle, Hyperplasia       |                      2                                                   |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                               4                    2                     |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  19                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7| 0| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 3| 8| 3|             
                                           | 1| 1| 2| 2| 1| 1| 2| 1| 1| 6| 2| 2| 2| 2| 1| 2| 1| 6| 1| 2| 1| 0| 0| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    250                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Galactocele                          |                            2                                             |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
      Fibrosis                             |                                                             4            |             
      Inflammation                         |                               3                             3            |             
      Ulcer                                |                               2                             3            |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Arthrosis                            |                                              4                           |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       | 1  1  1  1  1        1  1     1  1     1              1  1        1      |             
      Cerebrum, Atrophy                    |                                                                         1|             
      Meninges, Infiltration Cellular      | 1                                                                        |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                   1                                                      |             
      Infiltration Cellular                |                      1                                                   |             
      Glands, Degeneration                 |                                                                          |             
      Glands, Inflammation                 |                                                          1               |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                                  1                                3      |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |             1                                                            |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                         +|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy                          |          1                    2  1  1     1              1               |             
      Cortex, Cyst                         |                   3                                                      |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Infiltration Cellular                | 2                                      1                          1      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  20                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 0| 3| 3| 3| 0| 3| 3| 3| 3| 0| 0| 3| 3| 3| 3| 3| 3| 9| 5| 3| 3| 3| 3| 3| 3|            |
                                           | 8| 1| 1| 7| 7| 1| 2| 1| 0| 1| 5| 2| 1| 1| 1| 1| 1| 4| 9| 2| 2| 1| 2| 0| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    250                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  A  +  +  +  +  M  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                                  3                          2            |      4  2.3|
      Clear Cell Focus                     |                                     2                                    |      1  2.0|
      Eosinophilic Focus                   |    2                                                        1            |      6  1.5|
      Hemorrhage                           |                               3                                          |      1  3.0|
      Hepatodiaphragmatic Nodule           |                                     2                       1            |      2  1.5|
      Inflammation                         |                                                                          |      1  1.0|
      Mixed Cell Focus                     |                                                                          |      1  3.0|
      Necrosis                             |                                                 1                        |      3  1.3|
      Hepatocyte, Syncytial Alteration     |                                                                          |      1  1.0|
      Hepatocyte, Vacuolization Cytoplasmic|                                     3                 3                  |      2  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |    1                          1     1  1                                 |     12  1.4|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |    2           1  2  1  2  1  1  1     1  1  1     1  2  1  1        1  1|     33  1.4|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Ulcer                                |                                                       2                  |      1  2.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |    1                             2  1  1  1  2  1     4  1           1   |     23  1.4|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration                         |                                     1                                    |      4  1.3|
      Hemorrhage                           |                                     1              2                     |      2  1.5|
      Hyperplasia                          |       1                 1                                                |      3  1.0|
      Capsule, Hyperplasia                 | 2  1  2  2  2  2  2  2  2     1  2  2  1  2  2  1  1  2  1  1  2  2  2  1|     48  1.8|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  21                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 0| 3| 3| 3| 0| 3| 3| 3| 3| 0| 0| 3| 3| 3| 3| 3| 3| 9| 5| 3| 3| 3| 3| 3| 3|            |
                                           | 8| 1| 1| 7| 7| 1| 2| 1| 0| 1| 5| 2| 1| 1| 1| 1| 1| 4| 9| 2| 2| 1| 2| 0| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    250                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                    2  2                  |      2  2.0|
      Infiltration Cellular                |                   1                                                      |      2  1.5|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  M  M  +  +  M  +  +  +  +  +  M  +  M  +  +  +  +  +  +  M  +  +  M|  34        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Pars Distalis, Angiectasis           |                3                             2                           |      4  2.5|
      Pars Distalis, Hemorrhage            |                                                    2                     |      1  2.0|
      Pars Distalis, Hyperplasia           | 2  1  2           2  2  2              3     2           2  3     3      |     23  2.1|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |                                                                          |      1  1.0|
      Follicular Cell, Hyperplasia         | 2     3           1  1                 2  2  2  1     1  1  1        1  1|     25  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                                                          |   4        |
      Fat, Necrosis                        |                                                                          |      3  1.7|
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Atrophy                              |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                                                       3                  |      1  3.0|
      Cyst                                 |                4        1              2     1                    1  2   |     10  2.0|
      Hemorrhage                           |                            1                                             |      1  1.0|
      Infiltration Cellular                |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  2.0|
      Hemorrhage                           |                                                          2               |      1  2.0|
      Thrombosis                           |                                                                          |      1  2.0|
      Endometrium, Hyperplasia             | 3  3  3     2  3  4  4  4  3  4  3  3  3  4  4  4  3  2  4  4  3  4  4  4|     47  3.1|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pigmentation, Hemosiderin            |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |             +                                                            |   2        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  M  +  M  M  M  +  +  +  +  +  +  +  M  M  M  +  +  M  M  +  +  +|  29        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Hyperplasia                          |                                                                          |      3  2.7|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  22                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 0| 3| 3| 3| 0| 3| 3| 3| 3| 0| 0| 3| 3| 3| 3| 3| 3| 9| 5| 3| 3| 3| 3| 3| 3|            |
                                           | 8| 1| 1| 7| 7| 1| 2| 1| 0| 1| 5| 2| 1| 1| 1| 1| 1| 4| 9| 2| 2| 1| 2| 0| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    250                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  M  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  M  +  +  +  +  +  +  +|  41        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                                                                         2|      2  2.5|
      Pigmentation, Hemosiderin            |                                                                          |      1  1.0|
      Lymphoid Follicle, Hyperplasia       |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  M  +  +  +  +  +  +  M|  45        |
      Atrophy                              | 4        4                                            3                  |      5  3.4|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  48        |
      Galactocele                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Fibrosis                             |                                                                          |      1  4.0|
      Inflammation                         |                                                                          |      2  3.0|
      Ulcer                                |                                                                          |      2  2.5|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Arthrosis                            |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       | 1  1  1     1  1  1  1     1     1     1     1     1              1      |     26  1.0|
      Cerebrum, Atrophy                    |                                     3                                    |      2  2.0|
      Meninges, Infiltration Cellular      |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Degeneration                         |                                                                          |      1  1.0|
      Infiltration Cellular                |                                                                          |      1  1.0|
      Glands, Degeneration                 |                                  1                       1               |      2  1.0|
      Glands, Inflammation                 |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                                       2                  |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |                                                          2               |      3  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         | 2                                                                    1   |      3  1.3|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |                                                                      1   |      1  1.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  23                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 0| 3| 3| 3| 0| 3| 3| 3| 3| 0| 0| 3| 3| 3| 3| 3| 3| 9| 5| 3| 3| 3| 3| 3| 3|            |
                                           | 8| 1| 1| 7| 7| 1| 2| 1| 0| 1| 5| 2| 1| 1| 1| 1| 1| 4| 9| 2| 2| 1| 2| 0| 1|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    250                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Nephropathy                          |                1                                      1     1            |      9  1.1|
      Cortex, Cyst                         |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Infiltration Cellular                |                                                       2                  |      4  1.5|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  24                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 0| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 8| 3| 1| 1| 1| 1| 3| 1| 3| 3| 3| 3| 3| 1| 1| 3| 0| 3| 3| 3|             
                                           | 0| 2| 2| 1| 1| 1| 2| 2| 2| 8| 1| 1| 4| 2| 2| 2| 2| 2| 2| 3| 2| 7| 2| 2| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  M  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ulcer                                |                      2                                                   |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
      Peyer's Patch, Hyperplasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  A  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                                    3                 3   |             
      Eosinophilic Focus                   | 1  4  3  1                 2     2     2              2  2  2           2|             
      Hemorrhage                           |                                                       2                  |             
      Inflammation                         |                               2                                          |             
      Mineralization                       |                                                       1                  |             
      Mixed Cell Focus                     | 4                                                                        |             
      Necrosis                             |                   1           2                                   2      |             
      Bile Duct, Cyst                      |             2                                                            |             
      Hepatocyte, Hypertrophy              |                                                                          |             
      Hepatocyte, Vacuolization Cytoplasmic|                   3                                                      |             
      Serosa, Inflammation                 |                         2                                                |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |             1                    1                 1              2      |             
      Duct, Cyst                           |                                                    2                     |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                | 1  1     2  1     1  1        1     1  2     2  1  1     2  1     1  1   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                  3                                       |             
      Epithelium, Cyst                     |                                                    2                     |             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Glands, Hyperplasia                  |                                                                          |             
      Serosa, Infiltration Cellular        |                         2                                                |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 4        1  2  1     1        2        1              2  2  1     2      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                      1                                      1            |             
      Hemorrhage                           |                         2              1                                 |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  25                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 0| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 8| 3| 1| 1| 1| 1| 3| 1| 3| 3| 3| 3| 3| 1| 1| 3| 0| 3| 3| 3|             
                                           | 0| 2| 2| 1| 1| 1| 2| 2| 2| 8| 1| 1| 4| 2| 2| 2| 2| 2| 2| 3| 2| 7| 2| 2| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Hyperplasia                          |                   3                                                      |             
      Capsule, Hyperplasia                 | 3  2  2  2  2  1  2  1  1  1  2  3  2  2  3  2  2  2  1  2  2     2  2   |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                        2                                 |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  M  M  M  M  +  M  M  M  +  +  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Angiectasis           |          2                                                               |             
      Pars Distalis, Hemorrhage            |                                                                         3|             
      Pars Distalis, Hyperplasia           | 2  2        2        2        2  1           2     1  1  2  2            |             
      Pars Distalis, Necrosis              |                                                                          |             
      Pars Intermedia, Hyperplasia         |                                                 2                        |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         |       1  1  2     1  3  1  1  1  2        2  2  3  2  2  2  1        1  3|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                                                          |             
      Fat, Necrosis                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                 2                        |             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                                                 4                        |             
      Hemorrhage                           |                                                                          |             
      Infiltration Cellular                |                                                                          |             
      Inflammation                         |                3                                                         |             
      Endometrium, Hyperplasia             | 4  2  3  2  3     3  3     2  3  3  2  3  4  3  2  3  2  1  2     2  4  3|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Histiocyte    |                                                             1            |             
      Myelofibrosis                        |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Myeloid Cell, Hyperplasia            |                2                                                         |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                +                 +                                       |             
      Inguinal, Hyperplasia                |                                                                          |             
      Pancreatic, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  M  M  +  M  M  M  M  M  +  +  +  +  +  M  +  M  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  26                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 0| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 8| 3| 1| 1| 1| 1| 3| 1| 3| 3| 3| 3| 3| 1| 1| 3| 0| 3| 3| 3|             
                                           | 0| 2| 2| 1| 1| 1| 2| 2| 2| 8| 1| 1| 4| 2| 2| 2| 2| 2| 2| 3| 2| 7| 2| 2| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Hyperplasia                          |                                                             3            |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | M  M  M  +  +  +  +  M  +  M  M  +  M  +  +  M  M  M  M  +  +  M  M  +  +|             
      Hyperplasia                          |                                                             2            |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Pigmentation, Hemosiderin            |    2                                            2                    2   |             
      Lymphoid Follicle, Hyperplasia       |                               2                          2               |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
      Atrophy                              |                      3  4           2                    4     2         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       | 1  1           1        1     1  1                 1     1  1     1  1  1|             
      Cerebrum, Gliosis                    |                                                                          |             
      Cerebrum, Hemorrhage                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                    1                     |             
      Glands, Degeneration                 |                               1                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar Epithelium, Hyperplasia     |                            3                                             |             
      Alveolar Epithelium, Metaplasia      |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                   +      |             
                                            __________________________________________________________________________|             
   Lacrimal Gland                          |                            +                                             |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Casts Protein                        |                                                                          |             
      Mineralization                       |                                                                          |             
      Nephropathy                          | 1     1  1  1     1     3        1           1        1     1     1      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  27                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 0| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 8| 3| 1| 1| 1| 1| 3| 1| 3| 3| 3| 3| 3| 1| 1| 3| 0| 3| 3| 3|             
                                           | 0| 2| 2| 1| 1| 1| 2| 2| 2| 8| 1| 1| 4| 2| 2| 2| 2| 2| 2| 3| 2| 7| 2| 2| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Cortex, Cyst                         |                                                                          |             
                                            __________________________________________________________________________|             
   Ureter                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                   1     2                          1              1      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  28                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 1| 7| 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 3| 3| 6| 3| 3| 3| 6| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3| 6|            |
                                           | 2| 1| 1| 1| 9| 2| 1| 1| 8| 1| 1| 1| 1| 2| 2| 1| 2| 0| 1| 0| 3| 2| 2| 1| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    750                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  A  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A|  44        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A|  46        |
      Ulcer                                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  A|  45        |
      Peyer's Patch, Hyperplasia           |                                                                3         |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                                     2                                    |      3  2.7|
      Eosinophilic Focus                   | 2  2  2              1     2     1     3        1        1     3  2      |     22  2.0|
      Hemorrhage                           |                                                                          |      1  2.0|
      Inflammation                         |                                                                          |      1  2.0|
      Mineralization                       |                                                                          |      1  1.0|
      Mixed Cell Focus                     |                                                                          |      1  4.0|
      Necrosis                             |                                                             2            |      4  1.8|
      Bile Duct, Cyst                      |                                                                          |      1  2.0|
      Hepatocyte, Hypertrophy              |                                                    1                     |      1  1.0|
      Hepatocyte, Vacuolization Cytoplasmic|                                                                          |      1  3.0|
      Serosa, Inflammation                 |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular                |    1  2  2                    1                       1  1               |     10  1.3|
      Duct, Cyst                           |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |    1     2     1     1     1  1  2  1  2     1        2  1     1     1   |     30  1.3|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                 3                        |      2  3.0|
      Epithelium, Cyst                     |                            2                                             |      2  2.0|
      Epithelium, Hyperplasia              |                                              1                           |      1  1.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Glands, Hyperplasia                  |                            2                                             |      1  2.0|
      Serosa, Infiltration Cellular        |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |                               1     1                    1  2            |     15  1.6|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  29                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 1| 7| 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 3| 3| 6| 3| 3| 3| 6| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3| 6|            |
                                           | 2| 1| 1| 1| 9| 2| 1| 1| 8| 1| 1| 1| 1| 2| 2| 1| 2| 0| 1| 0| 3| 2| 2| 1| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    750                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  49        |
      Degeneration                         |    1                       1                                            1|      5  1.0|
      Hemorrhage                           |                                                             3            |      3  2.0|
      Hyperplasia                          |                            2                                   2         |      3  2.3|
      Capsule, Hyperplasia                 | 2  3  2  1  1  2  2  3  2  2  2  2  2  2  2  2  2  2  1  1     2     2  2|     46  1.9|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  49        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  M  +  +  +  M  +  +  +  +  M  M  M  M  M  M  M  M  +  M  M  +  M  M  +|  27        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Angiectasis           |                               2                                          |      2  2.0|
      Pars Distalis, Hemorrhage            |                                                                          |      1  3.0|
      Pars Distalis, Hyperplasia           | 2  1              2        2        1  4  1  2  2  3                 1   |     22  1.8|
      Pars Distalis, Necrosis              |          1                                                               |      1  1.0|
      Pars Intermedia, Hyperplasia         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         | 3     2        1  1  1     1  3  1  1  2  2     2  1  1  1     1     1   |     35  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                     +                                    |   1        |
      Fat, Necrosis                        |                                     2                                    |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Degeneration                         |                                                                2         |      1  2.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  49        |
      Cyst                                 |       2        2     2  1  2        3  1              2        3         |     10  2.0|
      Mineralization                       |                                  1                                       |      1  1.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration                         |                                                                          |      1  4.0|
      Hemorrhage                           | 2                                                                        |      1  2.0|
      Infiltration Cellular                |                3                                                         |      1  3.0|
      Inflammation                         |                                                                          |      1  3.0|
      Endometrium, Hyperplasia             | 4  4  3  3     3  4  4  2  4  4  4  3  4  3  3  4  4  4  2  2  3  3  4  2|     46  3.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  30                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 1| 7| 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 3| 3| 6| 3| 3| 3| 6| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3| 6|            |
                                           | 2| 1| 1| 1| 9| 2| 1| 1| 8| 1| 1| 1| 1| 2| 2| 1| 2| 0| 1| 0| 3| 2| 2| 1| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    750                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Infiltration Cellular, Histiocyte    |                                                                          |      1  1.0|
      Myelofibrosis                        |                                        1  2                              |      2  1.5|
      Pigmentation, Hemosiderin            |                         1                                                |      1  1.0|
      Myeloid Cell, Hyperplasia            |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |             +              +                                            +|   5        |
      Inguinal, Hyperplasia                |             3                                                            |      1  3.0|
      Pancreatic, Hyperplasia              |                            3                                             |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  38        |
      Hyperplasia                          |          2           2                                                   |      2  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +|  44        |
      Hyperplasia                          |                      2                                                   |      2  2.5|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  A  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  44        |
      Hyperplasia                          |          3                                         2                     |      2  2.5|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  +  +  +  M  +  +  +  M  +  M  M  +  M  +  +  +  +  +  +  +  +  +  +  +|  31        |
      Hyperplasia                          |          2                                                               |      2  2.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hematopoietic Cell Proliferation     |    3                                                                     |      1  3.0|
      Pigmentation, Hemosiderin            |                                                                      1   |      4  1.8|
      Lymphoid Follicle, Hyperplasia       |          2                                                               |      3  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +|  46        |
      Atrophy                              |             4                                                            |      6  3.2|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       | 1     1  1        1  1     1     1           1  1  1  1        1        1|     25  1.0|
      Cerebrum, Gliosis                    |                                                                         1|      1  1.0|
      Cerebrum, Hemorrhage                 |                                                                         1|      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Infiltration Cellular                |                                                                          |      1  1.0|
      Glands, Degeneration                 |                               2                                          |      2  1.5|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  31                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 1| 7| 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 3| 3| 6| 3| 3| 3| 6| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3| 6|            |
                                           | 2| 1| 1| 1| 9| 2| 1| 1| 8| 1| 1| 1| 1| 2| 2| 1| 2| 0| 1| 0| 3| 2| 2| 1| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    750                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar Epithelium, Hyperplasia     |                                                                          |      1  3.0|
      Alveolar Epithelium, Metaplasia      |                                                       2                  |      1  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |          +     +                                                         |   3        |
                                            __________________________________________________________________________|____________|
   Lacrimal Gland                          |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Casts Protein                        |          1                                                               |      1  1.0|
      Mineralization                       |                                              1                           |      1  1.0|
      Nephropathy                          |                   1  1        1  1  1     1     1     1  1     1         |     21  1.1|
      Cortex, Cyst                         |                      2                                                   |      1  2.0|
                                            __________________________________________________________________________|____________|
   Ureter                                  |                                                                         +|   1        |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular                |                                                    1                     |      5  1.2|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  32                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 5| 4| 7| 6| 6| 7| 7| 2| 7| 7| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 9| 2| 3| 2| 2| 3| 2| 3| 2| 2| 6| 2| 1| 1| 2| 2| 8| 3| 3| 2| 2| 2| 8| 3|             
                                           | 0| 8| 9| 0| 3| 9| 0| 5| 0| 9| 2| 7| 9| 0| 6| 9| 9| 9| 0| 0| 9| 9| 9| 5| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | M  +  +  +  A  +  +  A  +  +  M  M  +  A  M  +  +  M  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  A  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
      Peyer's Patch, Hyperplasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  A  +  +  +  +  +  +  +|             
      Peyer's Patch, Hyperplasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     | 1                                                                        |             
      Clear Cell Focus                     |                                                 1                       1|             
      Cyst                                 |                            2                                             |             
      Eosinophilic Focus                   |       3           2                       1                              |             
      Eosinophilic Focus, Multiple         |                                                                          |             
      Mixed Cell Focus                     |                                     1           1                        |             
      Necrosis                             |    2                       1  2                                          |             
      Hepatocyte, Hypertrophy              |                         1                                                |             
      Hepatocyte, Necrosis                 |                                                                         1|             
      Hepatocyte, Vacuolization Cytoplasmic|                                              2                           |             
      Vein, Thrombosis                     |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                                                          |             
      Duct, Cyst                           |                      2                                                   |             
      Duct, Fibrosis                       |                      2                                                   |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                | 1     1              1  1        1  1  1        1     1  2               |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ulcer                                |                                  1                                       |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                 1                        |             
      Metaplasia                           |                                                 1                        |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |    3                 2     2           1     1        1  1  1  2  3     1|             
      Inflammation                         |                                                                   3  1   |             
      Myocardium, Mineralization           |                                                                          |             
      Pericardium, Hyperplasia             |                                                                      2   |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  33                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 5| 4| 7| 6| 6| 7| 7| 2| 7| 7| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 9| 2| 3| 2| 2| 3| 2| 3| 2| 2| 6| 2| 1| 1| 2| 2| 8| 3| 3| 2| 2| 2| 8| 3|             
                                           | 0| 8| 9| 0| 3| 9| 0| 5| 0| 9| 2| 7| 9| 0| 6| 9| 9| 9| 0| 0| 9| 9| 9| 5| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Adrenal Cortical Nodule    |                                                                          |             
      Degeneration                         |                                              1                           |             
      Hemorrhage                           |                                                    1                     |             
      Hyperplasia                          | 1     1                    1        1           3        2  1  2        2|             
      Vacuolization Cytoplasmic            |                                                                          |             
      Capsule, Hyperplasia                 | 1     2     2  1     1  1        2                    1  2     1        1|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                               2                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  M  +  M  M  +  M  M  M  M  +  +  M  +  M  +  +  +  M  M  M  M  +  +  M|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  M  +|             
      Pars Distalis, Hyperplasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         | 1        2  1  1     2  1  2        1     1  1  2     3  2               |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atypia Cellular                      |                         1                                                |             
      Cyst                                 |       1                                                                  |             
      Granuloma Sperm                      |                                                                          |             
      Inflammation                         |                                                                          |             
      Mineralization                       |       1                                                                  |             
                                            __________________________________________________________________________|             
   Penis                                   |                                                                +         |             
      Inflammation                         |                                                                1         |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |          1                    2                                          |             
      Hyperplasia                          |                                                                          |             
      Infiltration Cellular                |       2                                                                  |             
      Inflammation                         |          2                                                     3         |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +|             
      Atrophy                              |                                        3                                 |             
      Infiltration Cellular                |             1                                                            |             
      Inflammation                         |                                                                      3   |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                        3                          3      |             
      Degeneration                         |       2           2           2     2        2  2        2              3|             
      Inflammation                         |                                                                      4   |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  34                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 5| 4| 7| 6| 6| 7| 7| 2| 7| 7| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 9| 2| 3| 2| 2| 3| 2| 3| 2| 2| 6| 2| 1| 1| 2| 2| 8| 3| 3| 2| 2| 2| 8| 3|             
                                           | 0| 8| 9| 0| 3| 9| 0| 5| 0| 9| 2| 7| 9| 0| 6| 9| 9| 9| 0| 0| 9| 9| 9| 5| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                      2   |             
      Myeloid Cell, Hyperplasia            |                                                                      2   |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                               +                                      +   |             
      Inguinal, Hyperplasia                |                                                                          |             
      Lumbar, Hyperplasia                  |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | M  M  M  M  +  +  M  +  M  M  +  M  +  M  M  +  M  M  +  M  M  M  +  M  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  M  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Congestion                           |                                                                          |             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  M  M  M  +  M  M  +  +  M  M  +  M  +  +  M  +  +  M  +  M  +  M  M  M|             
      Hyperplasia                          |                                                                2         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |    3                                                                     |             
      Hematopoietic Cell Proliferation     |                                                    4                 2   |             
      Lymphoid Follicle, Atrophy           |                                        3                                 |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  M  +  +  M  +  +  M  M  +  M  +  +  +  M  +  +  +  +  +  +  +  M  +  +|             
      Atrophy                              |                   3        4           4              2        4         |             
      Cyst                                 |                                        4                                 |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             
      Atrophy                              |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                                          3               |             
      Necrosis                             |                                                    2                     |             
      Ulcer                                |                                                          2               |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Vertebra, Degeneration               |    2                                                                     |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       | 1     1        1  1     1  1        2     1     1     1     1  1  1     1|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Histiocyte    |                                           2                       2      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  35                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 5| 4| 7| 6| 6| 7| 7| 2| 7| 7| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 9| 2| 3| 2| 2| 3| 2| 3| 2| 2| 6| 2| 1| 1| 2| 2| 8| 3| 3| 2| 2| 2| 8| 3|             
                                           | 0| 8| 9| 0| 3| 9| 0| 5| 0| 9| 2| 7| 9| 0| 6| 9| 9| 9| 0| 0| 9| 9| 9| 5| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Inflammation                         |                                                                      2   |             
      Alveolar Epithelium, Hyperplasia     |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Inflammation                         |                   1                             1                        |             
      Polyp, Inflammatory                  |                   3                                                      |             
      Nasolacrimal Duct, Inflammation      |    1                                                                     |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |          +                          +                                    |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |       1                                                                  |             
      Infarct                              |                                                                          |             
      Inflammation                         |                                                                      3   |             
      Nephropathy                          | 1  4  1  2  1  2  2  1  1  1  1              1  1     1  1  1     3     1|             
      Pigmentation, Bile                   |                                                                          |             
      Cortex, Cyst                         |          1                                                               |             
      Papilla, Inflammation                |                                                                2  2      |             
      Pelvis, Dilatation                   |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Calculus Micro Observation Only      |                                                                          |             
      Inflammation                         |                                                                3     2   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  36                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 5| 0| 5| 2| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 5| 7| 5| 5| 5| 0| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 8| 0| 3| 3| 2| 2| 5| 2| 2| 4| 2| 1| 3| 3| 6| 2| 5| 1| 4| 2| 2|            |
                                           | 9| 9| 7| 4| 4| 2| 0| 0| 9| 9| 2| 9| 9| 2| 9| 0| 0| 9| 8| 9| 5| 9| 4| 9| 9|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    CONTROL                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  A  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  M  A  +  A  +  +  +  +  +  +  +  +  +  M  +  +  M  +  M  A  +  A  +|  33        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  A  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  A  +|  42        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  A  +  M  +|  44        |
      Peyer's Patch, Hyperplasia           |                   2                                                      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  A  +  A  +  +  +  +  A  +  +  +  +  +  +  M  +  +  +  A  +  +  +|  42        |
      Peyer's Patch, Hyperplasia           |                   2                                                      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     | 1                                               2                        |      3  1.3|
      Clear Cell Focus                     |    1        2                                                           1|      5  1.2|
      Cyst                                 |                                                                          |      1  2.0|
      Eosinophilic Focus                   |                   1                       1                             2|      6  1.7|
      Eosinophilic Focus, Multiple         |                         2                                                |      1  2.0|
      Mixed Cell Focus                     |    1                                                                     |      3  1.0|
      Necrosis                             |       3                                2     1        1                  |      7  1.7|
      Hepatocyte, Hypertrophy              |                                                                          |      1  1.0|
      Hepatocyte, Necrosis                 |                                                                          |      1  1.0|
      Hepatocyte, Vacuolization Cytoplasmic|    1                       2                                            2|      4  1.8|
      Vein, Thrombosis                     |                                              4                           |      1  4.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                        +                                 |   1        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  49        |
      Inflammation                         |                                                    2                     |      1  2.0|
      Duct, Cyst                           |                                                                          |      1  2.0|
      Duct, Fibrosis                       |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                | 1  1              2  1     2           1  1     1     1  1  2            |     21  1.2|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  48        |
      Ulcer                                |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  48        |
      Infiltration Cellular                |                                                                          |      1  1.0|
      Metaplasia                           |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +|  48        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |                      1        2           3  2  1        1  1            |     18  1.6|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  37                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 5| 0| 5| 2| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 5| 7| 5| 5| 5| 0| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 8| 0| 3| 3| 2| 2| 5| 2| 2| 4| 2| 1| 3| 3| 6| 2| 5| 1| 4| 2| 2|            |
                                           | 9| 9| 7| 4| 4| 2| 0| 0| 9| 9| 2| 9| 9| 2| 9| 0| 0| 9| 8| 9| 5| 9| 4| 9| 9|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    CONTROL                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
      Inflammation                         |                                                                          |      2  2.0|
      Myocardium, Mineralization           |             2                                                            |      1  2.0|
      Pericardium, Hyperplasia             |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +|  47        |
      Accessory Adrenal Cortical Nodule    |                                                             1            |      1  1.0|
      Degeneration                         |                                                                          |      1  1.0|
      Hemorrhage                           |                                                                          |      1  1.0|
      Hyperplasia                          |    2              1  2  3                                                |     13  1.7|
      Vacuolization Cytoplasmic            |                                                 2                        |      1  2.0|
      Capsule, Hyperplasia                 | 2     1           2  1     1     1              1        1               |     19  1.3|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  49        |
      Hyperplasia                          | 1                                               2           1     2      |      5  1.6|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  M  +  +  +  +  M  +  M  M  +  M  +  M  +  +  +  M  +  M  M  M  M  M  +|  22        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +|  44        |
      Pars Distalis, Hyperplasia           |                   1                                                      |      1  1.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         | 2     1              2  2  2  2  1              1                        |     21  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |       +                                                                  |   2        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|  49        |
      Atypia Cellular                      |                                                                          |      1  1.0|
      Cyst                                 |                                                                          |      1  1.0|
      Granuloma Sperm                      |    2                                            1                        |      2  1.5|
      Inflammation                         |                                                       1                  |      1  1.0|
      Mineralization                       |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Penis                                   |                                                                          |   1        |
      Inflammation                         |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  M  +|  48        |
      Degeneration                         |                                                                         2|      3  1.7|
      Hyperplasia                          |                                                          2               |      1  2.0|
      Infiltration Cellular                |                                                                          |      1  2.0|
      Inflammation                         |                4                             2     2  4                  |      6  2.8|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +|  46        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  38                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 5| 0| 5| 2| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 5| 7| 5| 5| 5| 0| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 8| 0| 3| 3| 2| 2| 5| 2| 2| 4| 2| 1| 3| 3| 6| 2| 5| 1| 4| 2| 2|            |
                                           | 9| 9| 7| 4| 4| 2| 0| 0| 9| 9| 2| 9| 9| 2| 9| 0| 0| 9| 8| 9| 5| 9| 4| 9| 9|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    CONTROL                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Atrophy                              |                                                                          |      1  3.0|
      Infiltration Cellular                |                                                                          |      1  1.0|
      Inflammation                         |             2  1              2              1        3                  |      6  2.0|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|  49        |
      Atrophy                              |                                                                          |      2  3.0|
      Degeneration                         | 1  2           2  2  1  2     2                 3     3  3              3|     19  2.2|
      Inflammation                         |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                3                                                         |      1  3.0|
      Pigmentation, Hemosiderin            |                                                       1                  |      2  1.5|
      Myeloid Cell, Hyperplasia            |                                                       2                  |      2  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +        +                                                         |   4        |
      Inguinal, Hyperplasia                |                3                                                         |      1  3.0|
      Lumbar, Hyperplasia                  |                4                                                         |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  M  +  M  M  +  M  M  M  M  M  M  M  M  M  M  M  +  M  M  M  +  M  +  M|  14        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  M  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +|  43        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  +  +|  45        |
      Congestion                           |                                                             3            |      1  3.0|
      Hyperplasia                          |                                  3                                       |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  +  +  +  +  M  +  +  M  +  M  +  M  +  +  M  +  M  M  +  M  M  M  +  M|  24        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  3.0|
      Hematopoietic Cell Proliferation     |                                                    2                     |      3  2.7|
      Lymphoid Follicle, Atrophy           |             3                                                            |      2  3.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  M  +  +  M  M  +  M  +  +  +|  37        |
      Atrophy                              |    2     2  3  2  3  2     2  3     2              4        4     4  2   |     18  2.9|
      Cyst                                 |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  +  M  M  M  M  M  M  M  +  M  +  M  M  M|   3        |
      Atrophy                              |                                                                4         |      1  4.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |       1        2                                                         |      3  2.0|
      Necrosis                             |                                                                          |      1  2.0|
      Ulcer                                |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  39                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 5| 0| 5| 2| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 5| 7| 5| 5| 5| 0| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 8| 0| 3| 3| 2| 2| 5| 2| 2| 4| 2| 1| 3| 3| 6| 2| 5| 1| 4| 2| 2|            |
                                           | 9| 9| 7| 4| 4| 2| 0| 0| 9| 9| 2| 9| 9| 2| 9| 0| 0| 9| 8| 9| 5| 9| 4| 9| 9|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    CONTROL                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Vertebra, Degeneration               |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |       +                                +                                 |   2        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       | 1                    1     1  1  2              1                       1|     21  1.1|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  48        |
      Infiltration Cellular                |                               1                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Histiocyte    |                                                                          |      2  2.0|
      Inflammation                         |                                                                          |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |                                                       1                  |      1  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |             1                                                            |      1  1.0|
      Inflammation                         | 1        2  2                       1  1                                 |      7  1.3|
      Polyp, Inflammatory                  | 3                                                                        |      2  3.0|
      Nasolacrimal Duct, Inflammation      |       2                                                        1         |      3  1.3|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration                         |                                                                          |      1  1.0|
      Infarct                              |                2                                                         |      1  2.0|
      Inflammation                         |                               3              3                           |      3  3.0|
      Nephropathy                          | 1  1              1  1  1  1     1  1     1  1  2  1  2  1  3           2|     34  1.4|
      Pigmentation, Bile                   |                                        3                                 |      1  3.0|
      Cortex, Cyst                         |                                                                          |      1  1.0|
      Papilla, Inflammation                |                                                       2                  |      3  2.0|
      Pelvis, Dilatation                   |                                                                   2      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  M  +|  48        |
      Calculus Micro Observation Only      |                      1                                                   |      1  1.0|
      Inflammation                         |                3              4              3     3  2                  |      7  2.9|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  40                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 5| 3| 7| 7| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 7| 2| 2| 2| 3| 2| 2| 2| 3| 4| 2| 1| 6| 3| 2| 3| 3| 3| 9| 3| 2| 3| 3| 0| 2|             
                                           | 7| 9| 9| 9| 0| 9| 9| 9| 1| 0| 5| 4| 0| 0| 9| 0| 0| 0| 4| 6| 9| 0| 0| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | A  M  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  M  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                1                                                         |             
      Epithelium, Dysplasia                |                2                                                         |             
      Peyer's Patch, Hyperplasia           |             3                                                            |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                         1                                   2            |             
      Clear Cell Focus                     |          2  2                                               1            |             
      Cyst                                 |                                                                         1|             
      Eosinophilic Focus                   |             1                                1              2            |             
      Fibrosis                             |                                           1                              |             
      Inflammation, Chronic                |                   2                       2                              |             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis                             |                               2           2              1               |             
      Hepatocyte, Necrosis                 |                                     2                                    |             
      Hepatocyte, Syncytial Alteration     |                                                             1  1         |             
      Hepatocyte, Vacuolization Cytoplasmic|             3                       2                                    |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Duct, Cyst                           |                                                    2                     |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                | 1     1  1     1  1           2     1  1     1           1     1  1  1   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1  1  1  1  2  1  1  1  1     2        1  1  3  1  2  1        2  1  1   |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  M  +  +  +  +  +|             
      Degeneration                         |                                                             2            |             
      Hyperplasia                          | 2           2                                   2                        |             
      Capsule, Hyperplasia                 |    2              2  1        1           2  1  1           1     1  1   |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | M  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  M  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                            2     2  2                                    |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  M  M  M  +  M  +  M  +  +  +  M  +  +  +  M  M  +  +  +  M  M  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  41                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 5| 3| 7| 7| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 7| 2| 2| 2| 3| 2| 2| 2| 3| 4| 2| 1| 6| 3| 2| 3| 3| 3| 9| 3| 2| 3| 3| 0| 2|             
                                           | 7| 9| 9| 9| 0| 9| 9| 9| 1| 0| 5| 4| 0| 0| 9| 0| 0| 0| 4| 6| 9| 0| 0| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
      Pars Distalis, Cyst                  |                                                                1         |             
      Pars Distalis, Hyperplasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         | 1  3  1        2  1  3        1           1     2  1  1              1   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                                                          |             
      Cyst                                 |                                                                          |             
      Fat, Necrosis                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atypia Cellular                      |                                                                          |             
      Fibrosis                             |                                        2                                 |             
      Granuloma Sperm                      |                                                                2         |             
      Infiltration Cellular                |                                        2                                 |             
                                            __________________________________________________________________________|             
   Penis                                   |                         +                                                |             
      Concretion                           |                         3                                                |             
      Inflammation                         |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration, Cystic                 |                                                          2               |             
      Degeneration                         |                                           2                              |             
      Infiltration Cellular                |                                           1  1                       1   |             
      Inflammation                         |       3  3                                         2  2           2     1|             
      Mineralization                       |                            1                                             |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |          1                 2                                             |             
      Inflammation                         |                               2                          1           1   |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Degeneration                         |    2  2  2  2     3     3  3  2        2  2        2  3  3  2  2     2   |             
      Inflammation                         |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                       2                  |             
      Germinal Epithelium, Atrophy         |                                                                          |             
      Interstitial Cell, Hyperplasia       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                         4                                                |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Myeloid Cell, Hyperplasia            |                                           2        2     3               |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +     +                 +     +           +                              |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  42                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 5| 3| 7| 7| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 7| 2| 2| 2| 3| 2| 2| 2| 3| 4| 2| 1| 6| 3| 2| 3| 3| 3| 9| 3| 2| 3| 3| 0| 2|             
                                           | 7| 9| 9| 9| 0| 9| 9| 9| 1| 0| 5| 4| 0| 0| 9| 0| 0| 0| 4| 6| 9| 0| 0| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Inguinal, Hyperplasia                |                                                                          |             
      Inguinal, Pigmentation               |                                                                          |             
      Lumbar, Hyperplasia                  |       2                 3     4                                          |             
      Lumbar, Pigmentation                 |                                                                          |             
      Renal, Hyperplasia                   |                               4                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | M  M  M  M  M  M  +  +  +  M  +  +  M  M  M  M  +  M  +  +  +  M  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Pigmentation, Hemosiderin            |                         2                                                |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
      Congestion                           |                3                                                  3      |             
      Hematopoietic Cell Proliferation     |                2                                                  3      |             
      Hyperplasia                          |       2                                                                  |             
      Inflammation                         |                               3                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  M  +  M  M  M  M  +  +  M  M  +  M  M  M  M  M  M  M  M  +  M|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                            2  3                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  M  +  +  +  +  M  +  +  M  M  +  +  +  +  M  M  M  +  +  +  M  +|             
      Atrophy                              |                   3        4  4           4  4  3                        |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  +  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             
      Atrophy                              |                         4                                                |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Infiltration Cellular, Melanocyte    |                                                                          |             
      Inflammation                         |          4        4     3                          2                     |             
      Ulcer                                |       2  4        3     4                                                |             
      Hair Follicle, Atrophy               |                                                                          |             
      Sebaceous Gland, Cyst                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       | 1  1  1  1     1                          1                 1  1  1      |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                              2              1        1   |             
      Glands, Degeneration                 |                                                                          |             
      Glands, Inflammation                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar Epithelium, Hyperplasia     |                                                       2                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  43                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 5| 3| 7| 7| 7| 7| 7| 5| 5| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 7| 2| 2| 2| 3| 2| 2| 2| 3| 4| 2| 1| 6| 3| 2| 3| 3| 3| 9| 3| 2| 3| 3| 0| 2|             
                                           | 7| 9| 9| 9| 0| 9| 9| 9| 1| 0| 5| 4| 0| 0| 9| 0| 0| 0| 4| 6| 9| 0| 0| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    75 PPM                                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Alveolar Epithelium, Metaplasia      |                                           1                              |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                              1                          2|             
      Polyp, Inflammatory                  |    2                                                                     |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |                                                 2                        |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                      +   |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                            2  4                          2               |             
      Metaplasia, Osseous                  |                      1                                                   |             
      Mineralization                       |                                                                          |             
      Nephropathy                          | 1  1  1  1  1  1  1  1                 1  1  1  1  1  1     1  2  1  1   |             
      Cortex, Cyst                         |       1  2                                                     1  2     1|             
      Papilla, Inflammation                |                         2                                            2   |             
      Pelvis, Dilatation                   |                         2                             3                  |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Calculus Micro Observation Only      |                                                                          |             
      Inflammation                         |                         2  4  4                    3  2  2           4   |             
      Ulcer                                |                               2                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  44                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 3| 7| 7| 7| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 3| 2| 3| 8| 3| 4| 2| 2| 2| 3| 3| 3| 2| 2| 3| 2| 3| 7| 2| 3|            |
                                           | 0| 9| 9| 5| 0| 0| 9| 0| 0| 0| 1| 9| 9| 9| 0| 0| 0| 9| 9| 0| 9| 0| 8| 9| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    75 PPM                                 | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | M  +  +  +  +  M  +  +  M  +  A  +  +  +  +  +  +  M  +  +  +  +  A  +  +|  39        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +|  46        |
      Cyst                                 |                                                                          |      1  1.0|
      Epithelium, Dysplasia                |                                                                          |      1  2.0|
      Peyer's Patch, Hyperplasia           |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                               3                                          |      3  2.0|
      Clear Cell Focus                     |                                     2                                    |      4  1.8|
      Cyst                                 |                                                                          |      1  1.0|
      Eosinophilic Focus                   |                                     1  1  2  1  2                        |      8  1.4|
      Fibrosis                             |                                                                          |      1  1.0|
      Inflammation, Chronic                |                                                                          |      2  2.0|
      Mixed Cell Focus                     |                                  2        3                              |      2  2.5|
      Necrosis                             |       1  3        1     2                                      1         |      8  1.6|
      Hepatocyte, Necrosis                 |                                                                          |      1  2.0|
      Hepatocyte, Syncytial Alteration     |                                     1                       1           1|      5  1.0|
      Hepatocyte, Vacuolization Cytoplasmic|                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Duct, Cyst                           |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                | 1  1     1        1     1        1  2  1     1  1  1     1     1         |     26  1.1|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |    1  1     1  1  1  2        2     2  1     1  1  1     3  1  2     2  2|     36  1.4|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Degeneration                         | 3                                                                        |      2  2.5|
      Hyperplasia                          |                            1           2  2                          3  2|      8  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  45                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 3| 7| 7| 7| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 3| 2| 3| 8| 3| 4| 2| 2| 2| 3| 3| 3| 2| 2| 3| 2| 3| 7| 2| 3|            |
                                           | 0| 9| 9| 5| 0| 0| 9| 0| 0| 0| 1| 9| 9| 9| 0| 0| 0| 9| 9| 0| 9| 0| 8| 9| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    75 PPM                                 | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Capsule, Hyperplasia                 |                2     1     2     2  1  1  1        1  1           2  1  1|     22  1.3|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |          1                                         2                     |      5  1.8|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  +  M  +  +  +  +  M  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  M|  34        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  45        |
      Pars Distalis, Cyst                  |                                                                          |      1  1.0|
      Pars Distalis, Hyperplasia           |                                                          1               |      1  1.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         |    1  4                          1     1  1     2     3  2  1            |     21  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                  +                    +                 +|   3        |
      Cyst                                 |                                  2                                       |      1  2.0|
      Fat, Necrosis                        |                                                       2                 2|      2  2.0|
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atypia Cellular                      |          3                                                               |      1  3.0|
      Fibrosis                             |                                                                          |      1  2.0|
      Granuloma Sperm                      |                                                                          |      1  2.0|
      Infiltration Cellular                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Penis                                   |                            +                                             |   2        |
      Concretion                           |                                                                          |      1  3.0|
      Inflammation                         |                            2                                             |      1  2.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Degeneration, Cystic                 |                                                                          |      1  2.0|
      Degeneration                         |                   3                             4                        |      3  3.0|
      Infiltration Cellular                |                      2                             1                     |      5  1.2|
      Inflammation                         |             3                                   2           2     1  1   |     11  2.0|
      Mineralization                       |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular                |                                                                          |      2  1.5|
      Inflammation                         |             1                                                     1      |      5  1.2|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                               3                                          |      1  3.0|
      Degeneration                         |                            3     2  3  2  3  2  3                 3  2  2|     26  2.4|
      Inflammation                         |                            3                                             |      1  3.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  46                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 3| 7| 7| 7| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 3| 2| 3| 8| 3| 4| 2| 2| 2| 3| 3| 3| 2| 2| 3| 2| 3| 7| 2| 3|            |
                                           | 0| 9| 9| 5| 0| 0| 9| 0| 0| 0| 1| 9| 9| 9| 0| 0| 0| 9| 9| 0| 9| 0| 8| 9| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    75 PPM                                 | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Atrophy                              |                                                                          |      1  2.0|
      Germinal Epithelium, Atrophy         |          3                                                               |      1  3.0|
      Interstitial Cell, Hyperplasia       |          3                                                               |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                                                                          |      1  4.0|
      Pigmentation, Hemosiderin            |                         1                                         1      |      2  1.0|
      Myeloid Cell, Hyperplasia            |                               2                                          |      4  2.3|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +                                                           +      |   7        |
      Inguinal, Hyperplasia                |                                                                   2      |      1  2.0|
      Inguinal, Pigmentation               |                                                                   2      |      1  2.0|
      Lumbar, Hyperplasia                  |                                                                   2      |      4  2.8|
      Lumbar, Pigmentation                 |                                                                   2      |      1  2.0|
      Renal, Hyperplasia                   |       3                                                           2      |      3  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  M  M  +  +  M  M  M  +  +  M  M  +  M  M  M  M  M  M  +  +  +  +  +  +|  24        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +|  45        |
      Pigmentation, Hemosiderin            |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  A  +  +|  46        |
      Congestion                           |          3                                                               |      3  3.0|
      Hematopoietic Cell Proliferation     |          2                                                               |      3  2.3|
      Hyperplasia                          |                                                 2                        |      2  2.0|
      Inflammation                         |                                                 2                        |      2  2.5|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  M  M  M  +  +  +  M  M  +  M  +  +  M  M  M  +  +|  25        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |             3           2                                                |      4  2.5|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  M  +  M  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  37        |
      Atrophy                              | 3        3              4                 3        3                     |     11  3.5|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  +  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|   2        |
      Atrophy                              |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                   2      |      1  2.0|
      Infiltration Cellular, Melanocyte    |       2                                                                  |      1  2.0|
      Inflammation                         |             2                                      4                     |      6  3.2|
      Ulcer                                |                                                    4                     |      5  3.4|
      Hair Follicle, Atrophy               |                                                                      2   |      1  2.0|
      Sebaceous Gland, Cyst                |                                                                         1|      1  1.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  47                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 3| 7| 7| 7| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 3| 2| 3| 8| 3| 4| 2| 2| 2| 3| 3| 3| 2| 2| 3| 2| 3| 7| 2| 3|            |
                                           | 0| 9| 9| 5| 0| 0| 9| 0| 0| 0| 1| 9| 9| 9| 0| 0| 0| 9| 9| 0| 9| 0| 8| 9| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    75 PPM                                 | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       | 1  1                 1                 1        1  1     1  1     1      |     18  1.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular                |                                                 1                        |      4  1.3|
      Glands, Degeneration                 |                                              1                           |      1  1.0|
      Glands, Inflammation                 |    2                                                                     |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar Epithelium, Hyperplasia     |                1  4                          3  3                        |      5  2.6|
      Alveolar Epithelium, Metaplasia      |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |                                     2                                    |      3  1.7|
      Polyp, Inflammatory                  |                                                                          |      1  2.0|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                     +                                +   |   3        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |       4     2                                                            |      5  2.8|
      Metaplasia, Osseous                  |                                                                          |      1  1.0|
      Mineralization                       |                                                          1               |      1  1.0|
      Nephropathy                          | 1  1     1     1  1  1  2  1     1  1  1  1  1  2  1     1  1  1     1  1|     38  1.1|
      Cortex, Cyst                         |                                     1  1                    1            |      8  1.3|
      Papilla, Inflammation                |                               3                 2                        |      4  2.3|
      Pelvis, Dilatation                   |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Calculus Micro Observation Only      |                                                 2                        |      1  2.0|
      Inflammation                         |       3     4                 4                 3                 2      |     12  3.1|
      Ulcer                                |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  48                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 6| 6| 7| 6| 4| 7| 5| 5|             
                             DAY ON TEST   | 9| 2| 7| 2| 2| 3| 2| 3| 2| 0| 2| 2| 3| 0| 8| 2| 3| 4| 9| 2| 8| 8| 2| 7| 8|             
                                           | 6| 9| 9| 9| 2| 0| 9| 0| 4| 5| 9| 9| 0| 2| 8| 9| 0| 2| 1| 9| 3| 0| 9| 0| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    250                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | M  M  A  +  +  +  +  +  +  +  +  +  +  +  M  +  +  A  +  M  +  A  +  +  M|             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  A|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  M  +  A|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  A  +  A|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  A  +  +  +  A|             
      Parasite Metazoan                    |                      1                                                   |             
      Epithelium, Hyperplasia              |                      2                                                   |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  A  +  A  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                      2     1                                             |             
      Clear Cell Focus                     |                   1                                                      |             
      Eosinophilic Focus                   |                   3           3  3  1                                    |             
      Hepatodiaphragmatic Nodule           |                                                                          |             
      Mineralization                       |                                                                          |             
      Necrosis                             |       2        2                          2  2        1                 3|             
      Hepatocyte, Necrosis                 |          1                                                     2         |             
      Hepatocyte, Syncytial Alteration     |          1                    1                    1                     |             
      Hepatocyte, Vacuolization Cytoplasmic|                                                                          |             
      Vein, Thrombosis                     |                                                                      2   |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                 +                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |    1     1     1  1     2     1  1                    1  1               |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                                                          |             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                  +                                       |             
      Developmental Malformation           |                                  3                                       |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1        2  1     1  1  1  2  1  2  1  1  1     1        1  1           1|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +|             
      Degeneration                         |                                                                          |             
      Hyperplasia                          |                      1                       3           2               |             
      Capsule, Hyperplasia                 |                   2  1        2  2           1              2            |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  49                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 6| 6| 7| 6| 4| 7| 5| 5|             
                             DAY ON TEST   | 9| 2| 7| 2| 2| 3| 2| 3| 2| 0| 2| 2| 3| 0| 8| 2| 3| 4| 9| 2| 8| 8| 2| 7| 8|             
                                           | 6| 9| 9| 9| 2| 0| 9| 0| 4| 5| 9| 9| 0| 2| 8| 9| 0| 2| 1| 9| 3| 0| 9| 0| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    250                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Degeneration                         |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
      Degeneration                         |    1                                                                     |             
      Hyperplasia                          |                                  2        2                    3         |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  +  M  M  M  +  +  +  M  +  +  M  +  M  +  +  M  M  M  +  M  M  +  +  M|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Cyst                  |                                  1                                       |             
      Pars Distalis, Hyperplasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicle, Cyst                       |                                                             1            |             
      Follicular Cell, Hyperplasia         | 1  1     2  1  2  1  2  1  1  1  1  1        1  1     1  1           1   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                                 +                        |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Granuloma Sperm                      |                                                                          |             
      Bilateral, Fibrosis                  |                                                                   4      |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Cyst                                 |                                                                          |             
      Degeneration                         | 2        2                 2     2                                       |             
      Fibrosis                             |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Infiltration Cellular                |                                     1                                    |             
      Inflammation                         |             4           2                    4                    3      |             
      Necrosis                             |             3                                                            |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                                                          |             
      Inflammation                         |             1           2  1                                         1   |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |       3                                                                  |             
      Degeneration                         |    2     2           1        1     2     2           2           2      |             
      Inflammation                         |                                        4                             3   |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Tunic, Fibrosis                      |                                                                   4      |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Myeloid Cell, Hyperplasia            |             3           2              4                    2        3   |             
                                            __________________________________________________________________________|             
   Lymph Node                              |             +              +           +        +     +     +     +  +   |             
      Lumbar, Congestion                   |                                        2                                 |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  50                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 6| 6| 7| 6| 4| 7| 5| 5|             
                             DAY ON TEST   | 9| 2| 7| 2| 2| 3| 2| 3| 2| 0| 2| 2| 3| 0| 8| 2| 3| 4| 9| 2| 8| 8| 2| 7| 8|             
                                           | 6| 9| 9| 9| 2| 0| 9| 0| 4| 5| 9| 9| 0| 2| 8| 9| 0| 2| 1| 9| 3| 0| 9| 0| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    250                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Lumbar, Hyperplasia                  |             3                          2                             3   |             
      Lumbar, Inflammation                 |             1                                                            |             
      Renal, Congestion                    |                                        3                          3      |             
      Renal, Hyperplasia                   |                            2           3                    4            |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  M  +  +  M  +  +  M  +  +  M  M  +  M  +  M  +  M  +  +  +  M  M  M  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
      Congestion                           |                                                                         3|             
      Hyperplasia                          |                                                                      3   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  M  +  M  M  +  +  +  +  +  +  M  M  +  +  M  +  M  M  +  M  +  +  M|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Lymphoid Follicle, Atrophy           |                                                    3                     |             
      Lymphoid Follicle, Hyperplasia       |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  M  M|             
      Atrophy                              | 4                 3              2     4  4  3  3           3  3  2      |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  +  M|             
      Atrophy                              |                                                                      4   |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |             2           2                    4                           |             
      Ulcer                                |             3                                4                           |             
      Prepuce, Degeneration                |                                                                          |             
      Prepuce, Hyperplasia, Lymphoid       |                                              4                           |             
      Prepuce, Inflammation                |                                                                   4      |             
      Prepuce, Ulcer                       |                                                                   4      |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                 +                       +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       | 1        1                    1     1  1        1           1           1|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  M|             
      Foreign Body                         |                                                                          |             
      Infiltration Cellular                |                                                                          |             
      Glands, Degeneration                 |          1              2        2                                       |             
      Glands, Inflammation                 |                                     1                                    |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Congestion                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  51                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 6| 6| 7| 6| 4| 7| 5| 5|             
                             DAY ON TEST   | 9| 2| 7| 2| 2| 3| 2| 3| 2| 0| 2| 2| 3| 0| 8| 2| 3| 4| 9| 2| 8| 8| 2| 7| 8|             
                                           | 6| 9| 9| 9| 2| 0| 9| 0| 4| 5| 9| 9| 0| 2| 8| 9| 0| 2| 1| 9| 3| 0| 9| 0| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    250                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Infiltration Cellular, Histiocyte    |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Thrombosis                           |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                               2                                          |             
      Alveolar Epithelium, Metaplasia      |    1                                                  1                  |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                  2                                       |             
      Polyp, Inflammatory                  |                                  2                                       |             
      Nasolacrimal Duct, Inflammation      |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |       4                 3              4                    4            |             
      Nephropathy                          | 1  1     1  2  1  2  1     3  1  2  1     2  1  1  3  1  1     1     2   |             
      Cortex, Cyst                         |                   2                                   1           1      |             
      Papilla, Inflammation                |             1                                                        1   |             
      Papilla, Necrosis                    |                                        3                                 |             
      Pelvis, Dilatation                   |                                           2                              |             
      Renal Tubule, Vacuolization          |                                                                          |             
          Cytoplasmic                      |                                                                          |             
                                            __________________________________________________________________________|             
   Ureter                                  |                         +  +                                             |             
      Degeneration                         |                            2                                             |             
      Inflammation                         |                         2                                                |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Calculus Micro Observation Only      |       4                                                                  |             
      Infiltration Cellular                |                                                                          |             
      Inflammation                         |                                        2                    4            |             
      Muscularis, Inflammation             |                                                                      3   |             
      Muscularis, Necrosis                 |                                                                      3   |             
      Serosa, Fibrosis                     |                                                                   4      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  52                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 5| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 5| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 2| 2| 2| 2| 2| 7| 2| 2| 2| 2| 3| 7| 3| 2| 3| 6| 3| 2| 3| 3| 3|            |
                                           | 9| 9| 0| 9| 4| 9| 9| 9| 9| 4| 9| 9| 9| 9| 0| 9| 0| 9| 0| 3| 0| 9| 0| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    250                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  A  +  A  +  +  +  +  A  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +|  37        |
      Epithelium, Hyperplasia              |                                           2                              |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  43        |
      Parasite Metazoan                    |                                                                          |      1  1.0|
      Epithelium, Hyperplasia              |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |             1                                      2                 1   |      5  1.4|
      Clear Cell Focus                     |          2           2                 1        1              2  3      |      7  1.7|
      Eosinophilic Focus                   | 1        2              2                             2                  |      8  2.1|
      Hepatodiaphragmatic Nodule           |                         2                                                |      1  2.0|
      Mineralization                       |                         2                                                |      1  2.0|
      Necrosis                             |       3                    4                 2           3               |     10  2.4|
      Hepatocyte, Necrosis                 |    1                                                                     |      3  1.3|
      Hepatocyte, Syncytial Alteration     |                1        3           1           2                 1      |      8  1.4|
      Hepatocyte, Vacuolization Cytoplasmic|          1              2  2           2                                 |      4  1.8|
      Vein, Thrombosis                     |                                                          2               |      2  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |       1  1           1                    1  1                 1  1  1   |     17  1.1|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |                                        2                                 |      1  2.0|
      Mineralization                       |          1                                                     1         |      2  1.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   1        |
      Developmental Malformation           |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 2  1  2           1  2  1           2     3        1  2  1  1        3   |     29  1.4|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  53                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 5| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 5| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 2| 2| 2| 2| 2| 7| 2| 2| 2| 2| 3| 7| 3| 2| 3| 6| 3| 2| 3| 3| 3|            |
                                           | 9| 9| 0| 9| 4| 9| 9| 9| 9| 4| 9| 9| 9| 9| 0| 9| 0| 9| 0| 3| 0| 9| 0| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    250                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Degeneration                         |       1                                                                  |      1  1.0|
      Hyperplasia                          |                   1  2                       1  2  1           2         |      9  1.7|
      Capsule, Hyperplasia                 | 1     1  1  1  2  1  2        1        1     1  1        2     2  1      |     20  1.4|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Degeneration                         |                      2                                                   |      1  2.0|
      Hyperplasia                          |                                           2              1               |      2  1.5|
      Mineralization                       |                      2                                                   |      1  2.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Degeneration                         |                                                                          |      1  1.0|
      Hyperplasia                          |    1  2  2                                      1     1                  |      8  1.8|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  M  M  +  +  +  +  M  M  +  +  M  +  +  +  +  M  M  +  +  M  +  M|  28        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | M  +  +  +  M  +  +  +  +  M  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +|  45        |
      Pars Distalis, Cyst                  |                                                       1                  |      2  1.0|
      Pars Distalis, Hyperplasia           |                                                       1                  |      1  1.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicle, Cyst                       |                                                                          |      1  1.0|
      Follicular Cell, Hyperplasia         |          1        3           1  3        1     2  1  1     2  1     3  2|     29  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Granuloma Sperm                      | 2                                                                        |      1  2.0|
      Bilateral, Fibrosis                  |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Cyst                                 |          2                                                               |      1  2.0|
      Degeneration                         |          2              4           2              4              2      |      9  2.4|
      Fibrosis                             |    3                                                                     |      1  3.0|
      Hyperplasia                          |                                                    2                     |      1  2.0|
      Infiltration Cellular                |          2        2     1                             1                 2|      6  1.5|
      Inflammation                         | 4  2                             2                    1  3  2        1   |     11  2.5|
      Necrosis                             |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |                                                                   1      |      1  1.0|
      Inflammation                         |             2                                                            |      5  1.4|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                            3              2                              |      3  2.7|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  54                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 5| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 5| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 2| 2| 2| 2| 2| 7| 2| 2| 2| 2| 3| 7| 3| 2| 3| 6| 3| 2| 3| 3| 3|            |
                                           | 9| 9| 0| 9| 4| 9| 9| 9| 9| 4| 9| 9| 9| 9| 0| 9| 0| 9| 0| 3| 0| 9| 0| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    250                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Degeneration                         |          3  2  3  2     2              2        2                    2   |     16  2.0|
      Inflammation                         |                                                                          |      2  3.5|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Tunic, Fibrosis                      |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Myeloid Cell, Hyperplasia            |                   3        2     2                 3                     |      9  2.7|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +     +     +                                                      |  11        |
      Lumbar, Congestion                   |                                                                          |      1  2.0|
      Lumbar, Hyperplasia                  |                   3                                                      |      4  2.8|
      Lumbar, Inflammation                 |                   2                                                      |      2  1.5|
      Renal, Congestion                    |                                                                          |      2  3.0|
      Renal, Hyperplasia                   |                                                                          |      3  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  M  M  M  M  +  +  +  M  +  +  M  M  +  +  M  +  M  M  +  +  +  +  +  +|  27        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Congestion                           |                                                                          |      1  3.0|
      Hyperplasia                          |    4                                                                    2|      3  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  M  M  +  +  M  +  M  M  +  +  M  M  M  M  M  +  M  M  +  +  +  M  +|  27        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hematopoietic Cell Proliferation     |                   3                                      2               |      2  2.5|
      Lymphoid Follicle, Atrophy           |                                                                          |      1  3.0|
      Lymphoid Follicle, Hyperplasia       | 3                    2                                                   |      2  2.5|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  M  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  M|  39        |
      Atrophy                              | 3        3           2     4                 3  2     3  4  3     2      |     20  3.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  +  M  +  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|   3        |
      Atrophy                              |             4                                                            |      2  4.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |                   3                                                      |      4  2.8|
      Ulcer                                |                                                                          |      2  3.5|
      Prepuce, Degeneration                |                   3                                                      |      1  3.0|
      Prepuce, Hyperplasia, Lymphoid       |                                                                          |      1  4.0|
      Prepuce, Inflammation                |                                                             4            |      2  4.0|
      Prepuce, Ulcer                       |                                                             4            |      2  4.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  55                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 5| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 5| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 2| 2| 2| 2| 2| 7| 2| 2| 2| 2| 3| 7| 3| 2| 3| 6| 3| 2| 3| 3| 3|            |
                                           | 9| 9| 0| 9| 4| 9| 9| 9| 9| 4| 9| 9| 9| 9| 0| 9| 0| 9| 0| 3| 0| 9| 0| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    250                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |    1     1        1           1     1  1  1        1  1           1     1|     19  1.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Foreign Body                         |                                                                2         |      1  2.0|
      Infiltration Cellular                |                1  1              1                                   2   |      4  1.3|
      Glands, Degeneration                 |                                                                          |      3  1.7|
      Glands, Inflammation                 |                                                 2                        |      2  1.5|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Congestion                           |                                                          3               |      1  3.0|
      Infiltration Cellular, Histiocyte    |                                                                3         |      1  3.0|
      Pigmentation, Hemosiderin            |                                                                3         |      1  3.0|
      Thrombosis                           |                                                          1               |      1  1.0|
      Alveolar Epithelium, Hyperplasia     |                                                                      1   |      2  1.5|
      Alveolar Epithelium, Metaplasia      |                                                                          |      2  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         | 2  3                             1                                       |      4  2.0|
      Polyp, Inflammatory                  | 2                                                                        |      2  2.0|
      Nasolacrimal Duct, Inflammation      |       1                                                                  |      1  1.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                           +                    +         |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |             3                                                            |      5  3.6|
      Nephropathy                          | 1  1     2     1  1  1  1  1  1  1  3  1  3     1     1  1  2  1  1  1  1|     40  1.4|
      Cortex, Cyst                         |                      2        1                                          |      5  1.4|
      Papilla, Inflammation                |                   2                                                      |      3  1.3|
      Papilla, Necrosis                    |                                                                          |      1  3.0|
      Pelvis, Dilatation                   |                                                                          |      1  2.0|
      Renal Tubule, Vacuolization          |                                                                          |            |
          Cytoplasmic                      |                                                                2         |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  56                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 5| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 5| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 8| 2| 2| 2| 2| 2| 2| 7| 2| 2| 2| 2| 3| 7| 3| 2| 3| 6| 3| 2| 3| 3| 3|            |
                                           | 9| 9| 0| 9| 4| 9| 9| 9| 9| 4| 9| 9| 9| 9| 0| 9| 0| 9| 0| 3| 0| 9| 0| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    250                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ureter                                  |                                                                          |   2        |
      Degeneration                         |                                                                          |      1  2.0|
      Inflammation                         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Calculus Micro Observation Only      |                                                                         2|      2  3.0|
      Infiltration Cellular                |                            2                                             |      1  2.0|
      Inflammation                         |             3     2        1                             2               |      6  2.3|
      Muscularis, Inflammation             |                                                                          |      1  3.0|
      Muscularis, Necrosis                 |                                                                          |      1  3.0|
      Serosa, Fibrosis                     |                                                                          |      1  4.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  57                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 6| 5| 5| 7| 7| 7| 7| 7| 7| 6| 2| 7| 7| 7| 6| 5| 7| 7| 7| 4| 7|             
                             DAY ON TEST   | 5| 2| 3| 2| 1| 6| 8| 3| 3| 0| 3| 2| 2| 6| 5| 2| 3| 2| 7| 2| 3| 2| 3| 3| 3|             
                                           | 9| 9| 0| 9| 8| 5| 2| 0| 0| 8| 0| 9| 9| 9| 9| 9| 0| 9| 9| 0| 0| 9| 0| 0| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  A  M  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  A  +  +  M  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  A  +  A  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                      1   |             
      Basophilic Focus                     |       2                                                                  |             
      Clear Cell Focus                     |                      1                          2                        |             
      Eosinophilic Focus                   |                         2        3           2  1           2            |             
      Fibrosis                             |                                                                          |             
      Hemorrhage                           |                            2                                             |             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis                             |             2     3                       1  2                           |             
      Thrombosis                           |                                                                          |             
      Hepatocyte, Hyperplasia              |                                                             4            |             
      Hepatocyte, Hypertrophy              | 2              1           1        1           1           1  1  1     1|             
      Hepatocyte, Necrosis                 |                            2     1  1           1           3        1   |             
      Hepatocyte, Syncytial Alteration     | 1  1     1  1              1     2  1  1  1     2              1  2  1   |             
      Hepatocyte, Vacuolization Cytoplasmic|                                                    1  2                  |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|             
      Acinus, Hyperplasia                  |                                                                          |             
      Duct, Degeneration                   |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                | 1  1                    1              2     1  2  1        1     1     1|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Epithelium, Hyperplasia              |                                                                          |             
      Serosa, Inflammation                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  |                               +                                          |             
      Inflammation, Granulomatous          |                               3                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1     1  1              1        2  2        2  1           2     1     1|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  58                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 6| 5| 5| 7| 7| 7| 7| 7| 7| 6| 2| 7| 7| 7| 6| 5| 7| 7| 7| 4| 7|             
                             DAY ON TEST   | 5| 2| 3| 2| 1| 6| 8| 3| 3| 0| 3| 2| 2| 6| 5| 2| 3| 2| 7| 2| 3| 2| 3| 3| 3|             
                                           | 9| 9| 0| 9| 8| 5| 2| 0| 0| 8| 0| 9| 9| 9| 9| 9| 0| 9| 9| 0| 0| 9| 0| 0| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                     1                                    |             
      Hyperplasia                          |                                                                   2      |             
      Capsule, Hyperplasia                 |    1     1     2              1  1           1  1           1     1      |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  M  M  M  +  +  M  +  M  +  +  M  M  M  +  +  M  M  M  M  M  M  M  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +|             
      Pars Distalis, Cyst                  |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         | 1  2  1  2  2        1  1        2  2  1           1  1        1  1     1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                                                          |             
      Fat, Necrosis                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Degeneration                         |             2                    3                       3     2         |             
      Infiltration Cellular                |                      1                                                   |             
      Inflammation                         |             4  4              2  3           1                       2  3|             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular                |                                        1                                 |             
      Inflammation                         |             1                                         3  4               |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Degeneration                         |    1  3     3                    2        2  2  3  2  2     3  2  2  2   |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Mineralization                       |                                                                          |             
      Germinal Epithelium, Degeneration    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pigmentation, Hemosiderin            |                1                                                         |             
      Myeloid Cell, Hyperplasia            |                                  2                                       |             
                                            __________________________________________________________________________|             
   Lymph Node                              |             +  +                       +                                 |             
      Lumbar, Hyperplasia                  |             3  2                                                         |             
      Lumbar, Pigmentation                 |             1                                                            |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  M  +  +  M  M  +  +  +  +  M  M  M  M  M  M  +  +  +  M  +  +  +  M  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  59                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 6| 5| 5| 7| 7| 7| 7| 7| 7| 6| 2| 7| 7| 7| 6| 5| 7| 7| 7| 4| 7|             
                             DAY ON TEST   | 5| 2| 3| 2| 1| 6| 8| 3| 3| 0| 3| 2| 2| 6| 5| 2| 3| 2| 7| 2| 3| 2| 3| 3| 3|             
                                           | 9| 9| 0| 9| 8| 5| 2| 0| 0| 8| 0| 9| 9| 9| 9| 9| 0| 9| 9| 0| 0| 9| 0| 0| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                      2   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  A  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Congestion                           |                                                                          |             
      Inflammation                         |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | M  M  +  M  M  +  M  +  +  M  +  +  +  M  M  +  +  M  +  M  M  M  M  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|             
      Lymphoid Follicle, Atrophy           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  M  +  +  M  M  +  +  +  M  +  +  +  A  M  +  +  +  M  +  +  +  +  +|             
      Atrophy                              |    3                             4     3              4              3  2|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  +  M  M  M  M  M  M  M  M  M  M  +  M  M  M  M  M|             
      Atrophy                              |                                                          4               |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                              3                           |             
      Ulcer                                |                                              2                           |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Vertebra, Degeneration               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |          1                 1  1  1  1        1     1  1     1            |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                     2                                    |             
      Glands, Degeneration                 |                                                             1            |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Infiltration Cellular, Histiocyte    |          2                                                               |             
      Alveolar Epithelium, Hyperplasia     |       1                       1                                          |             
      Alveolar Epithelium, Metaplasia      |                      1                       1     1                     |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Edema                                |                                                                          |             
      Hemorrhage                           |                                                                          |             
      Inflammation                         |                                                                          |             
      Nasolacrimal Duct, Inflammation      |                                              2                           |             
      Respiratory Epithelium, Inflammation |                                                                          |             
                                            __________________________________________________________________________|             
   Pleura                                  |                            +                                             |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Glands, Cyst                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  60                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 7| 7| 6| 5| 5| 7| 7| 7| 7| 7| 7| 6| 2| 7| 7| 7| 6| 5| 7| 7| 7| 4| 7|             
                             DAY ON TEST   | 5| 2| 3| 2| 1| 6| 8| 3| 3| 0| 3| 2| 2| 6| 5| 2| 3| 2| 7| 2| 3| 2| 3| 3| 3|             
                                           | 9| 9| 0| 9| 8| 5| 2| 0| 0| 8| 0| 9| 9| 9| 9| 9| 0| 9| 9| 0| 0| 9| 0| 0| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    750                                    | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
    PPM                                    | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Glands, Hemorrhage                   |                                     1                                    |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation                         |                                           3                              |             
      Nephropathy                          | 1  1  1  1  1        1  1  1  1  1  1  1     1  1           1  1  1     1|             
      Cortex, Cyst                         |          1           1                                                   |             
      Papilla, Inflammation                |                                  2                    3                  |             
      Pelvis, Dilatation                   |             2                                                           2|             
                                            __________________________________________________________________________|             
   Ureter                                  |             +                                                            |             
      Degeneration                         |             2                                                            |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Calculus Micro Observation Only      |                                                 2                        |             
      Infiltration Cellular                |                                  2                                       |             
      Inflammation                         |             3                    2        3           4              3   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  61                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 1| 7| 6| 7| 7| 7| 7| 6| 6| 7| 7| 6| 4| 4| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7|            |
                             DAY ON TEST   | 7| 2| 3| 2| 3| 3| 2| 7| 0| 2| 3| 6| 1| 8| 3| 3| 2| 3| 3| 3| 4| 5| 2| 3| 3|            |
                                           | 9| 9| 2| 5| 0| 0| 9| 9| 7| 9| 0| 0| 8| 0| 0| 0| 9| 0| 0| 0| 7| 9| 9| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    750                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  M  +  +  +  +  +  A  +  +  +  M  A  A  +  +  +  +  M  +  A  +  +  +  +|  38        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  M  A  +  +  +  +  +  +  A  +  +  +  +|  43        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +|  45        |
      Epithelium, Hyperplasia              |          3                                                               |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  A  +  +  +  +  M  A  +  +  +  +  +  +  +  +  +  +  +|  43        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  M  +  +  +  +  M  A  +  +  +  +  +  +  A  +  +  +  +|  41        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  1.0|
      Basophilic Focus                     |          1           1                                   2               |      4  1.5|
      Clear Cell Focus                     |                                                          1               |      3  1.3|
      Eosinophilic Focus                   |             2  2                 2           3     1  1  2               |     12  1.9|
      Fibrosis                             |                                                                   3      |      1  3.0|
      Hemorrhage                           |                                                                   4      |      2  3.0|
      Mixed Cell Focus                     |                1                                                         |      1  1.0|
      Necrosis                             |                            2     1     3                 4  1     2      |     10  2.1|
      Thrombosis                           |                                                                   2      |      1  2.0|
      Hepatocyte, Hyperplasia              |                                                                          |      1  4.0|
      Hepatocyte, Hypertrophy              |             1        1  1        1  1                    1  1  1         |     17  1.1|
      Hepatocyte, Necrosis                 |                                                    3     1           3  2|     10  1.8|
      Hepatocyte, Syncytial Alteration     |          1  1     1  1  1        1     1           1        1  1         |     23  1.1|
      Hepatocyte, Vacuolization Cytoplasmic|                                           2                              |      3  1.7|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Acinus, Hyperplasia                  |                         1                                                |      1  1.0|
      Duct, Degeneration                   |          2                                                               |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |          2  1                 1           1  1  1     1     1  1        1|     20  1.2|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Cyst                                 |                                                                1         |      1  1.0|
      Epithelium, Hyperplasia              |                                           1                              |      1  1.0|
      Serosa, Inflammation                 |       1                                                                  |      1  1.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
      Inflammation, Granulomatous          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |       +                                                                  |   1        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  62                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 1| 7| 6| 7| 7| 7| 7| 6| 6| 7| 7| 6| 4| 4| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7|            |
                             DAY ON TEST   | 7| 2| 3| 2| 3| 3| 2| 7| 0| 2| 3| 6| 1| 8| 3| 3| 2| 3| 3| 3| 4| 5| 2| 3| 3|            |
                                           | 9| 9| 2| 5| 0| 0| 9| 9| 7| 9| 0| 0| 8| 0| 0| 0| 9| 0| 0| 0| 7| 9| 9| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    750                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|  47        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |    2     2  1  1  1        3  2              1  3  3     2     2     2  1|     25  1.6|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hemorrhage                           |                                                                          |      1  1.0|
      Hyperplasia                          |    1                       2              1                              |      4  1.5|
      Capsule, Hyperplasia                 |          1     2     1        1                 1     2  1     2         |     17  1.2|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia                          |                      2                                                   |      1  2.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  +  +  +  +  M  +  +  M  M  +  +  +  +  +  M  M  M  +  +  M  +  M  +|  25        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Pars Distalis, Cyst                  |                                        3                                 |      1  3.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         |    1     1  2  1     1  1  2  4           3  1  1  2  3  3        1  2  3|     32  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                     +                       +            |   2        |
      Fat, Necrosis                        |                                                             3            |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration                         |          2                                4                              |      2  3.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Degeneration                         |          4  3                                                            |      6  2.8|
      Infiltration Cellular                |    3     2                                         2                     |      4  2.0|
      Inflammation                         |    2           4     3     2  2                                         3|     13  2.7|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular                |    2                                                                     |      2  1.5|
      Inflammation                         |                   3  1  1                                                |      6  2.2|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                         4                                                |      1  4.0|
      Degeneration                         |    3        2  2  1  2     2                             2        2     2|     22  2.1|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                           4                              |      1  4.0|
      Mineralization                       |          2                                                               |      1  2.0|
      Germinal Epithelium, Degeneration    |          2                                                               |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  63                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 1| 7| 6| 7| 7| 7| 7| 6| 6| 7| 7| 6| 4| 4| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7|            |
                             DAY ON TEST   | 7| 2| 3| 2| 3| 3| 2| 7| 0| 2| 3| 6| 1| 8| 3| 3| 2| 3| 3| 3| 4| 5| 2| 3| 3|            |
                                           | 9| 9| 2| 5| 0| 0| 9| 9| 7| 9| 0| 0| 8| 0| 0| 0| 9| 0| 0| 0| 7| 9| 9| 0| 0|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    750                                    | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
    PPM                                    | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pigmentation, Hemosiderin            |                                                                          |      1  1.0|
      Myeloid Cell, Hyperplasia            |                   3  3                                               2   |      4  2.5|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                                          |   3        |
      Lumbar, Hyperplasia                  |                                                                          |      2  2.5|
      Lumbar, Pigmentation                 |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  +  +  M  +  +  +  M  M  M  +  M  +  M  +  +  +  +  M  M  M  M  M  +  +|  27        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | M  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  44        |
      Pigmentation, Hemosiderin            |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Atrophy                              |                         3                                                |      1  3.0|
      Congestion                           |                2                                      2                  |      2  2.0|
      Inflammation                         |                1                                                         |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  M  M  M  +  +  +  M  M  M  M  +  +  +  M  +  +  M  M  +  M  +  +  +  +|  25        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Lymphoid Follicle, Atrophy           |                         2                                                |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  +  +  +  +  M  +  M  M  +  M  +  +  M  +  +  +  M  +  M  +  +|  34        |
      Atrophy                              |          3        3  4                             3           3         |     11  3.2|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|   3        |
      Atrophy                              |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation                         |          2                                      3                        |      3  2.7|
      Ulcer                                |          1                                      3                        |      3  2.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Vertebra, Degeneration               |                         2                                                |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |    1        1  1     1     1  1              1        1  1           1   |     19  1.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  64                                                               
NTP Experiment-Test: 05210-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 04/24/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:49:38  
                                                                                                                                    
 ____________