Skip to Main Navigation
Skip to Page Content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Share This:
https://ntp.niehs.nih.gov/go/3641

TDMS Study 05210-03 Pathology Tables

NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34




       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




































Note:  Animals arranged according to CID number

                                                              Page   1


NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 7| 5| 7| 6| 7| 7| 7| 1| 7| 7| 4| 7| 7| 7| 1| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 0| 3| 5| 3| 3| 3| 1| 3| 3| 9| 3| 3| 3| 9| 2| 8| 3| 3| 3| 3|             
                                           | 6| 5| 8| 5| 5| 7| 4| 1| 5| 4| 5| 1| 5| 5| 6| 6| 4| 6| 4| 1| 7| 6| 5| 5| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  A  +  M  +  +  +  +  A  A  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |             X  X     X        X        X           X                 X   |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                 +                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X        X                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X        X        X                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X        X        X                                          |             
      Lymphoma Malignant                   |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X                 X                                          |             
      Lymphoma Malignant                   |                                                                          |             
      Pheochromocytoma Benign              |                                                 X                    X   |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                   X                                                      |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
      Pars Distalis, Adenoma               | X  X  X     X           X  X  X           X     X  X     X        X     X|             
      Pars Distalis, Adenoma, Multiple     |                   X                                                      |             
 _____________________________________________________________________________________________________________________|             

                                                             Page   2                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 7| 5| 7| 6| 7| 7| 7| 1| 7| 7| 4| 7| 7| 7| 1| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 0| 3| 5| 3| 3| 3| 1| 3| 3| 9| 3| 3| 3| 9| 2| 8| 3| 3| 3| 3|             
                                           | 6| 5| 8| 5| 5| 7| 4| 1| 5| 4| 5| 1| 5| 5| 6| 6| 4| 6| 4| 1| 7| 6| 5| 5| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
      Pars Distalis, Leukemia Mononuclear  |             X                 X                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  M  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                   X                                      X               |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Adenoma                              |             X                                                     X      |             
      Carcinoma                            |                                     X                                    |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X                 X                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X                                                            |             
      Polyp Stromal                        |          X                                               X               |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X        X        X                                      X   |             
                                            __________________________________________________________________________|             
   Lymph Node                              |             +                                            +               |             
      Inguinal, Lymphoma Malignant         |                                                                          |             
      Lumbar, Histiocytic Sarcoma          |                                                          X               |             
      Lumbar, Leukemia Mononuclear         |             X                                                            |             
      Lumbar, Lymphoma Malignant           |                                                                          |             
      Renal, Lymphoma Malignant            |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | M  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  M  M  +  M  M  +  +|             
      Leukemia Mononuclear                 |             X                                                            |             
      Lymphoma Malignant                   |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                      X   |             
      Lymphoma Malignant                   |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                X     X        X                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X  X     X        X                                      X   |             
      Lymphoma Malignant                   |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X  X     X        X        X           X                 X   |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page   3                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 7| 5| 7| 6| 7| 7| 7| 1| 7| 7| 4| 7| 7| 7| 1| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 0| 3| 5| 3| 3| 3| 1| 3| 3| 9| 3| 3| 3| 9| 2| 8| 3| 3| 3| 3|             
                                           | 6| 5| 8| 5| 5| 7| 4| 1| 5| 4| 5| 1| 5| 5| 6| 6| 4| 6| 4| 1| 7| 6| 5| 5| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Adenoma                              |                      X                                                   |             
      Carcinoma                            |                         X                                                |             
      Carcinoma, Multiple                  |                   X                                                      |             
      Fibroadenoma                         |    X              X           X                    X     X  X            |             
      Fibroadenoma, Multiple               |                            X           X                          X      |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                                                                         X|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Astrocytoma Malignant                |                                           X                              |             
      Leukemia Mononuclear                 |                               X                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X                 X                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                                        X                                 |             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |             X  X     X        X                                      X   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                +        +|             
      External Ear, Sarcoma                |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                    +                     |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Adenoma                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X        X        X                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X                 X                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                          X               |             
      Leukemia Mononuclear                 |             X  X     X        X        X           X                 X   |             
 _____________________________________________________________________________________________________________________|             

                                                             Page   4                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 7| 5| 7| 6| 7| 7| 7| 1| 7| 7| 4| 7| 7| 7| 1| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 0| 3| 5| 3| 3| 3| 1| 3| 3| 9| 3| 3| 3| 9| 2| 8| 3| 3| 3| 3|             
                                           | 6| 5| 8| 5| 5| 7| 4| 1| 5| 4| 5| 1| 5| 5| 6| 6| 4| 6| 4| 1| 7| 6| 5| 5| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS - cont                   |                                                                          |             
                                           |                                                                          |             
      Lymphoma Malignant                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page   5                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 7| 7| 6| 0| 7| 6| 7| 7| 7| 4| 7| 7| 3|            |
                             DAY ON TEST   | 5| 3| 3| 3| 3| 6| 3| 3| 8| 3| 5| 2| 3| 0| 8| 1| 3| 6| 3| 3| 3| 8| 3| 3| 1|            |
                                           | 9| 5| 6| 5| 6| 8| 6| 4| 6| 5| 4| 7| 6| 4| 3| 8| 5| 5| 6| 5| 4| 6| 6| 6| 8|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  A  +  +  A  +  +  +  +  +  +  A  +  A  +  +  +  +  +  +  +|  44        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |                                        X                                 |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  A  +  +  +  A  +  +  A|  41        |
      Leukemia Mononuclear                 |                                        X                                 |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | A  +  +  +  +  A  +  +  A  +  +  +  +  A  +  A  +  A  +  +  +  +  +  +  A|  41        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                           X                              |          1 |
      Leukemia Mononuclear                 |       X           X           X  X     X           X                     |         13 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +                    +        +  +                          +     +      |   7        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Histiocytic Sarcoma                  |                                           X                              |          1 |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                               X  X                                       |          4 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                  X     X                                 |          2 |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                         +                                                |   1        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                  X     X           X                     |          6 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                   X                    X           X                     |          6 |
      Lymphoma Malignant                   |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                    X                     |          3 |
      Lymphoma Malignant                   |                                                                         X|          1 |
      Pheochromocytoma Benign              |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page   6                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 7| 7| 6| 0| 7| 6| 7| 7| 7| 4| 7| 7| 3|            |
                             DAY ON TEST   | 5| 3| 3| 3| 3| 6| 3| 3| 8| 3| 5| 2| 3| 0| 8| 1| 3| 6| 3| 3| 3| 8| 3| 3| 1|            |
                                           | 9| 5| 6| 5| 6| 8| 6| 4| 6| 5| 4| 7| 6| 4| 3| 8| 5| 5| 6| 5| 4| 6| 6| 6| 8|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                               X        X                                 |          3 |
      Pars Distalis, Adenoma               | X     X  X  X  X  X  X        X     X     X           X  X        X  X   |         27 |
      Pars Distalis, Adenoma, Multiple     |                            X                                X            |          3 |
      Pars Distalis, Leukemia Mononuclear  |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      C-Cell, Adenoma                      |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Adenoma                              |                                                                          |          2 |
      Carcinoma                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                        X                                 |          3 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Polyp Stromal                        |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                               X  X     X           X                     |          8 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                                         +|   3        |
      Inguinal, Lymphoma Malignant         |                                                                         X|          1 |
      Lumbar, Histiocytic Sarcoma          |                                                                          |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          1 |
      Lumbar, Lymphoma Malignant           |                                                                         X|          1 |
      Renal, Lymphoma Malignant            |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  M  M  +  +  +  M  +  +  M  +  +  +  M  M  +  +  +  +  +|  37        |
      Leukemia Mononuclear                 |                                        X                                 |          2 |
      Lymphoma Malignant                   |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                   X                    X                                 |          4 |
      Lymphoma Malignant                   |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                   X                    X                                 |          5 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page   7                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 7| 7| 6| 0| 7| 6| 7| 7| 7| 4| 7| 7| 3|            |
                             DAY ON TEST   | 5| 3| 3| 3| 3| 6| 3| 3| 8| 3| 5| 2| 3| 0| 8| 1| 3| 6| 3| 3| 3| 8| 3| 3| 1|            |
                                           | 9| 5| 6| 5| 6| 8| 6| 4| 6| 5| 4| 7| 6| 4| 3| 8| 5| 5| 6| 5| 4| 6| 6| 6| 8|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                   X                    X                                 |          7 |
      Lymphoma Malignant                   |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |       X           X           X  X     X           X                     |         13 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                                        X                                 |          2 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  48        |
      Adenoma                              |                                                                          |          1 |
      Carcinoma                            |                                        X                                 |          2 |
      Carcinoma, Multiple                  |                                                                          |          1 |
      Fibroadenoma                         |    X  X     X        X     X        X                             X      |         13 |
      Fibroadenoma, Multiple               |                   X              X                    X                  |          6 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                  X                                       |          1 |
      Subcutaneous Tissue, Fibroma         |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Astrocytoma Malignant                |                                                                          |          1 |
      Leukemia Mononuclear                 |                                        X                                 |          2 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|  45        |
      Leukemia Mononuclear                 |                                        X                                 |          3 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Adenoma         |                                                                          |          1 |
      Histiocytic Sarcoma                  |                                           X                              |          1 |
      Leukemia Mononuclear                 |                               X  X     X           X                     |          9 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page   8                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 7| 7| 6| 0| 7| 6| 7| 7| 7| 4| 7| 7| 3|            |
                             DAY ON TEST   | 5| 3| 3| 3| 3| 6| 3| 3| 8| 3| 5| 2| 3| 0| 8| 1| 3| 6| 3| 3| 3| 8| 3| 3| 1|            |
                                           | 9| 5| 6| 5| 6| 8| 6| 4| 6| 5| 4| 7| 6| 4| 3| 8| 5| 5| 6| 5| 4| 6| 6| 6| 8|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 SPECIAL SENSES SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                           +                              |   3        |
      External Ear, Sarcoma                |                                           X                              |          1 |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                      +                                                   |   1        |
      Adenoma                              |                      X                                                   |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                        X                                 |          4 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                                        X                                 |          3 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                           X                              |          2 |
      Leukemia Mononuclear                 |       X           X           X  X     X           X                     |         13 |
      Lymphoma Malignant                   |                                                                         X|          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page   9                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7| 6| 4| 5|             
                             DAY ON TEST   | 3| 6| 3| 3| 3| 3| 3| 4| 7| 3| 3| 3| 3| 3| 3| 8| 3| 0| 3| 3| 3| 3| 1| 1| 0|             
                                           | 6| 2| 6| 6| 1| 5| 6| 6| 5| 6| 6| 5| 4| 4| 6| 6| 6| 1| 5| 5| 5| 6| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  A|             
      Leukemia Mononuclear                 |                                              X                       X   |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Granulocytic                |                                                                         X|             
      Leukemia Mononuclear                 |       X  X  X        X           X           X  X              X     X   |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                                      +   |             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X           X           X                       X   |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                   X      |             
      Leukemia Mononuclear                 |          X           X           X           X                       X   |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X           X           X           X                       X   |             
      Pheochromocytoma Malignant           |                                                                          |             
      Bilateral, Pheochromocytoma Benign   |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I|             
      Leukemia Mononuclear                 |                                                                          |             
      Pars Distalis, Adenoma               |       X        X  X     X  X        X           X     X        X         |             
      Pars Distalis, Adenoma, Multiple     |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  10                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7| 6| 4| 5|             
                             DAY ON TEST   | 3| 6| 3| 3| 3| 3| 3| 4| 7| 3| 3| 3| 3| 3| 3| 8| 3| 0| 3| 3| 3| 3| 1| 1| 0|             
                                           | 6| 2| 6| 6| 1| 5| 6| 6| 5| 6| 6| 5| 4| 4| 6| 6| 6| 1| 5| 5| 5| 6| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
      Pars Distalis, Carcinoma             |                                                                          |             
      Pars Distalis, Leukemia Mononuclear  |          X                                                               |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, C-Cell, Adenoma           |                                                                          |             
      C-Cell, Adenoma                      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                       X   |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
      Polyp Stromal                        |                                                    X                     |             
      Endometrium, Sarcoma Stromal         |    X                                                                     |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                    +                     |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X  X                                X                       X   |             
                                            __________________________________________________________________________|             
   Lymph Node                              |             +                                +                           |             
      Pancreatic, Leukemia Mononuclear     |                                              X                           |             
      Renal, Leukemia Mononuclear          |             X                                                            |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  M  +  +  M  M  +  +  +  +  M  +  +  +  +  +  +  M  M  +  +  +  +  M|             
      Leukemia Mononuclear                 |             X        X                       X                       X   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X  X                    X           X                       X   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Leukemia Mononuclear                 |          X  X                                X  X                    X   |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Granulocytic                |                                                                         X|             
      Leukemia Mononuclear                 |       X  X  X        X           X           X  X              X     X   |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Leukemia Mononuclear                 |                      X                                               X   |             
      Lymphoma Malignant                   |                                                                   X      |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                 X     X                  |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  11                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7| 6| 4| 5|             
                             DAY ON TEST   | 3| 6| 3| 3| 3| 3| 3| 4| 7| 3| 3| 3| 3| 3| 3| 8| 3| 0| 3| 3| 3| 3| 1| 1| 0|             
                                           | 6| 2| 6| 6| 1| 5| 6| 6| 5| 6| 6| 5| 4| 4| 6| 6| 6| 1| 5| 5| 5| 6| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Carcinoma                            |                                                 X                        |             
      Fibroadenoma                         |          X  X                 X  X     X              X                  |             
      Fibroadenoma, Multiple               |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
      Subcutaneous Tissue, Fibrosarcoma    |                                     X                                    |             
      Subcutaneous Tissue, Lipoma          |                                                                          |             
      Subcutaneous Tissue, Sarcoma         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                      +   |             
      Leukemia Mononuclear                 |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma, Metastatic, Pituitary     |                                                                          |             
          Gland                            |                                                                          |             
      Leukemia Mononuclear                 |                                              X                           |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma,        |                                                                          |             
          Multiple                         |                                                                          |             
      Leukemia Granulocytic                |                                                                         X|             
      Leukemia Mononuclear                 |             X                    X           X                       X   |             
      Sarcoma, Metastatic, Uncertain       |                                                                          |             
          Primary Site                     |                                                    X                     |             
      Mediastinum, Sarcoma, Metastatic,    |                                                                          |             
           Uncertain Primary Site          |                                                    X                     |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
      Glands, Adenoma                      |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                  X           X                       X   |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  12                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 7| 7| 6| 4| 5|             
                             DAY ON TEST   | 3| 6| 3| 3| 3| 3| 3| 4| 7| 3| 3| 3| 3| 3| 3| 8| 3| 0| 3| 3| 3| 3| 1| 1| 0|             
                                           | 6| 2| 6| 6| 1| 5| 6| 6| 5| 6| 6| 5| 4| 4| 6| 6| 6| 1| 5| 5| 5| 6| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Granulocytic                |                                                                         X|             
      Leukemia Mononuclear                 |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Granulocytic                |                                                                         X|             
      Leukemia Mononuclear                 |       X  X  X        X           X           X  X              X     X   |             
      Lymphoma Malignant                   |                                                                   X      |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  13                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 7| 7| 7| 6| 7| 7| 6| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|            |
                             DAY ON TEST   | 3| 6| 3| 1| 3| 3| 4| 3| 3| 3| 3| 3| 0| 3| 3| 3| 2| 3| 3| 2| 3| 3| 3| 0| 3|            |
                                           | 6| 8| 5| 9| 5| 6| 7| 4| 5| 6| 1| 5| 9| 6| 6| 1| 4| 5| 6| 4| 5| 5| 4| 9| 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      |
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                   X                                                      |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |             X     X                                                      |          3 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                            X                                             |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                   X                                                      |          3 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Granulocytic                |                                                                          |          1 |
      Leukemia Mononuclear                 |          X  X     X        X     X                    X     X     X     X|         18 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +                                      +                                +|   4        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                   X                                                      |          2 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                   X        X                                             |          3 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                   X        X                                             |          3 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X        X        X                          X                  |          8 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
      Leukemia Mononuclear                 |          X        X        X                          X     X           X|         11 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X        X        X                                X            |          9 |
      Pheochromocytoma Malignant           |                                                                X         |          1 |
      Bilateral, Pheochromocytoma Benign   |          X                                               X               |          2 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  14                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 7| 7| 7| 6| 7| 7| 6| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|            |
                             DAY ON TEST   | 3| 6| 3| 1| 3| 3| 4| 3| 3| 3| 3| 3| 0| 3| 3| 3| 2| 3| 3| 2| 3| 3| 3| 0| 3|            |
                                           | 6| 8| 5| 9| 5| 6| 7| 4| 5| 6| 1| 5| 9| 6| 6| 1| 4| 5| 6| 4| 5| 5| 4| 9| 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      |
   FISCHER 344 RATS 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                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                   X                                   X                  |          2 |
      Pars Distalis, Adenoma               |    X           X              X           X     X  X              X  X   |         17 |
      Pars Distalis, Adenoma, Multiple     | X     X                          X     X     X              X            |          6 |
      Pars Distalis, Carcinoma             |          X                                                               |          1 |
      Pars Distalis, Leukemia Mononuclear  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Bilateral, C-Cell, Adenoma           | X                                                                        |          1 |
      C-Cell, Adenoma                      |                                              X        X        X         |          3 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                            X                                             |          1 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                   X        X                          X                  |          5 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                            X                                             |          2 |
      Polyp Stromal                        |                   X                                      X               |          3 |
      Endometrium, Sarcoma Stromal         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                               +                          +               |   3        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                   X        X                          X     X           X|          9 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                   +                                                      |   3        |
      Pancreatic, Leukemia Mononuclear     |                   X                                                      |          2 |
      Renal, Leukemia Mononuclear          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  M  +  +  +  M  +  M  M  M  +  M  M  +  +  +  M  +  +  M  +  +|  34        |
      Leukemia Mononuclear                 |                                                       X                  |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X        X                                   X                  |          3 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X  X     X        X                          X                  |         10 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |             X     X        X     X                    X     X            |         11 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  15                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 7| 7| 7| 6| 7| 7| 6| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|            |
                             DAY ON TEST   | 3| 6| 3| 1| 3| 3| 4| 3| 3| 3| 3| 3| 0| 3| 3| 3| 2| 3| 3| 2| 3| 3| 3| 0| 3|            |
                                           | 6| 8| 5| 9| 5| 6| 7| 4| 5| 6| 1| 5| 9| 6| 6| 1| 4| 5| 6| 4| 5| 5| 4| 9| 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      |
   FISCHER 344 RATS 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               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Granulocytic                |                                                                          |          1 |
      Leukemia Mononuclear                 |          X  X     X        X     X                    X     X     X     X|         18 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |                   X                                                      |          3 |
      Lymphoma Malignant                   |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          2 |
      Carcinoma                            |                                                                          |          1 |
      Fibroadenoma                         |    X              X  X           X     X  X  X  X     X  X  X           X|         18 |
      Fibroadenoma, Multiple               |                                     X                                    |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |          1 |
      Subcutaneous Tissue, Lipoma          | X                                                                        |          1 |
      Subcutaneous Tissue, Sarcoma         |                                  X                                       |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Carcinoma, Metastatic, Pituitary     |                                                                          |            |
          Gland                            |          X                                                               |          1 |
      Leukemia Mononuclear                 |                   X        X                          X                  |          4 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  M  +  M  +|  43        |
      Leukemia Mononuclear                 |                   X                                   X                  |          2 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Adenoma,        |                                                                          |            |
          Multiple                         |             X                                                            |          1 |
      Leukemia Granulocytic                |                                                                          |          1 |
      Leukemia Mononuclear                 |          X        X        X                          X     X            |          9 |
      Sarcoma, Metastatic, Uncertain       |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  16                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 7| 7| 7| 6| 7| 7| 6| 5| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|            |
                             DAY ON TEST   | 3| 6| 3| 1| 3| 3| 4| 3| 3| 3| 3| 3| 0| 3| 3| 3| 2| 3| 3| 2| 3| 3| 3| 0| 3|            |
                                           | 6| 8| 5| 9| 5| 6| 7| 4| 5| 6| 1| 5| 9| 6| 6| 1| 4| 5| 6| 4| 5| 5| 4| 9| 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      |
   FISCHER 344 RATS 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                 |                                                                          |            |
                                           |                                                                          |            |
          Primary Site                     |                                                                          |          1 |
      Mediastinum, Sarcoma, Metastatic,    |                                                                          |            |
           Uncertain Primary Site          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                   X        X                                             |          3 |
      Glands, Adenoma                      |    X                                                                     |          1 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                      +   |   1        |
      Carcinoma                            |                                                                      X   |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                   X        X     X                    X     X           X|          9 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Granulocytic                |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Granulocytic                |                                                                          |          1 |
      Leukemia Mononuclear                 |          X  X     X        X     X                    X     X     X     X|         18 |
      Lymphoma Malignant                   |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  17                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 3| 6| 6| 7| 7| 7| 7| 7| 7| 5| 6| 7| 7| 6| 7| 7| 4| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 9| 8| 5| 3| 3| 3| 3| 3| 3| 0| 9| 3| 3| 5| 3| 3| 4| 3| 6| 3|             
                                           | 5| 6| 6| 5| 5| 3| 9| 9| 6| 6| 5| 4| 5| 5| 2| 4| 5| 6| 1| 6| 4| 9| 5| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
      Polyp Adenomatous                    |                                     X                                    |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X        X                    X     X           X           X   |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +                                   +        +     +           +   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                          X                           |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                      X   |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |    +                                                                     |             
      Squamous Cell Papilloma              |    X                                                                     |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                    X                                 |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                            X                                             |             
      Carcinoma                            |                                                                          |             
      Leukemia Mononuclear                 |          X        X                    X                                 |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X        X                                                      |             
      Pheochromocytoma Malignant           |                      X                       X                           |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  18                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 3| 6| 6| 7| 7| 7| 7| 7| 7| 5| 6| 7| 7| 6| 7| 7| 4| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 9| 8| 5| 3| 3| 3| 3| 3| 3| 0| 9| 3| 3| 5| 3| 3| 4| 3| 6| 3|             
                                           | 5| 6| 6| 5| 5| 3| 9| 9| 6| 6| 5| 4| 5| 5| 2| 4| 5| 6| 1| 6| 4| 9| 5| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
      Pars Distalis, Adenoma               |                         X  X  X  X  X  X        X  X     X     X     X   |             
      Pars Distalis, Adenoma, Multiple     | X                                                                        |             
      Pars Distalis, Carcinoma             |                                                                         X|             
      Pars Distalis, Leukemia Mononuclear  |                   X                                                      |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      C-Cell, Adenoma                      |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Carcinoma                            |                               X                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                          X                           |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
      Polyp Stromal                        |                                                          X               |             
      Bilateral, Polyp Stromal             |                                                             X            |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X        X                          X                           |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                   +                                                  +   |             
      Leukemia Mononuclear                 |                                                                          |             
      Inguinal, Leukemia Mononuclear       |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                   X                                                  X   |             
      Renal, Leukemia Mononuclear          |                                                                      X   |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  M  +  +  M  +  +  +  +  +  M  +  M  +  M  +  +  +  M  +  +  M  +  +  +|             
      Leukemia Mononuclear                 |          X        X                          X                           |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                          X           X           X   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X        X                                                      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X        X                    X     X           X               |             
      Rhabdomyosarcoma, Metastatic,        |                                                                          |             
          Uncertain Primary Site           |                X                                                         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X        X                    X     X           X           X   |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  19                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 3| 6| 6| 7| 7| 7| 7| 7| 7| 5| 6| 7| 7| 6| 7| 7| 4| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 9| 8| 5| 3| 3| 3| 3| 3| 3| 0| 9| 3| 3| 5| 3| 3| 4| 3| 6| 3|             
                                           | 5| 6| 6| 5| 5| 3| 9| 9| 6| 6| 5| 4| 5| 5| 2| 4| 5| 6| 1| 6| 4| 9| 5| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                          X                           |             
      Rhabdomyosarcoma, Metastatic,        |                                                                          |             
          Uncertain Primary Site           |                X                                                         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma                            |                                           X                          X   |             
      Fibroadenoma                         | X        X                          X        X     X  X                  |             
      Fibroadenoma, Multiple               |                            X                                      X     X|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Squamous Cell Carcinoma              |                                  X                                       |             
      Squamous Cell Papilloma              |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma, Metastatic, Pituitary     |                                                                          |             
          Gland                            |                                                                         X|             
      Leukemia Mononuclear                 |                   X                                                      |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +|             
      Leukemia Mononuclear                 |                   X                                                  X   |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                         X                                                |             
      Carcinoma, Metastatic, Mammary Gland |                                           X                              |             
      Leukemia Mononuclear                 |          X        X                    X     X                       X   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                                      |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |             +                                                  +         |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X        X                    X                                 |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  20                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 3| 6| 6| 7| 7| 7| 7| 7| 7| 5| 6| 7| 7| 6| 7| 7| 4| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 9| 8| 5| 3| 3| 3| 3| 3| 3| 0| 9| 3| 3| 5| 3| 3| 4| 3| 6| 3|             
                                           | 5| 6| 6| 5| 5| 3| 9| 9| 6| 6| 5| 4| 5| 5| 2| 4| 5| 6| 1| 6| 4| 9| 5| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS - cont                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |          X        X                    X     X           X           X   |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  21                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 7| 6| 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 4|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 0| 7| 3| 0| 8| 3| 3| 3| 3| 3| 3| 3| 5| 3| 2| 3| 3| 8|            |
                                           | 5| 5| 9| 5| 6| 5| 5| 9| 4| 6| 2| 5| 6| 5| 5| 6| 5| 5| 5| 8| 6| 4| 6| 6| 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      |
   FISCHER 344 RATS 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        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |       X                 X                                      X         |          3 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Polyp Adenomatous                    |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |                         X                                      X         |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  A|  47        |
      Leukemia Mononuclear                 |                         X                                                |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |                         X                                      X         |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |                         X                                      X         |          2 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X                 X              X              X     X  X     X  X|         16 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                         +                                                |   6        |
      Leukemia Mononuclear                 |                         X                                                |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                         X                                                |          3 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                         X                                                |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X                 X                                                |          4 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                         X                                      X         |          2 |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
      Squamous Cell Papilloma              |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X                 X                                      X         |          5 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
      Carcinoma                            |                                                                      X   |          1 |
      Leukemia Mononuclear                 | X     X                 X                                   X  X     X   |          9 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  22                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 7| 6| 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 4|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 0| 7| 3| 0| 8| 3| 3| 3| 3| 3| 3| 3| 5| 3| 2| 3| 3| 8|            |
                                           | 5| 5| 9| 5| 6| 5| 5| 9| 4| 6| 2| 5| 6| 5| 5| 6| 5| 5| 5| 8| 6| 4| 6| 6| 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      |
   FISCHER 344 RATS 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                   |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 | X                       X                                      X     X   |          6 |
      Pheochromocytoma Malignant           |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  M  +  +  M  +  M  M  M  +  +  +  +  M  +  +  M  +  +  +  +  +|  42        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X                 X                                      X         |          4 |
      Pars Distalis, Adenoma               | X              X  X  X        X  X  X  X  X  X        X     X     X      |         24 |
      Pars Distalis, Adenoma, Multiple     |                                                                          |          1 |
      Pars Distalis, Carcinoma             |                                                                          |          1 |
      Pars Distalis, Leukemia Mononuclear  | X                                                                    X   |          3 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                         X                                                |          1 |
      C-Cell, Adenoma                      |                                                                      X   |          2 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Carcinoma                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X                       X                                      X     X   |          6 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                         X                                                |          2 |
      Polyp Stromal                        |             X                          X        X                        |          4 |
      Bilateral, Polyp Stromal             |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X                 X              X                       X     X  X|         10 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                         +                                      +         |   4        |
      Leukemia Mononuclear                 |                                                                X         |          1 |
      Inguinal, Leukemia Mononuclear       |                                                                X         |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                X         |          1 |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          2 |
      Renal, Leukemia Mononuclear          |                         X                                      X         |          3 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +|  41        |
      Leukemia Mononuclear                 | X     X                 X                                      X     X   |          8 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  23                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 7| 6| 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 4|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 0| 7| 3| 0| 8| 3| 3| 3| 3| 3| 3| 3| 5| 3| 2| 3| 3| 8|            |
                                           | 5| 5| 9| 5| 6| 5| 5| 9| 4| 6| 2| 5| 6| 5| 5| 6| 5| 5| 5| 8| 6| 4| 6| 6| 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      |
   FISCHER 344 RATS 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, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X                 X              X                       X     X   |         10 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X                 X                                   X  X         |          7 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X                 X                                      X     X   |         10 |
      Rhabdomyosarcoma, Metastatic,        |                                                                          |            |
          Uncertain Primary Site           |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 | X  X  X                 X              X              X     X  X     X  X|         16 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 | X                       X                                      X         |          5 |
      Rhabdomyosarcoma, Metastatic,        |                                                                          |            |
          Uncertain Primary Site           |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Carcinoma                            |                                                                          |          2 |
      Fibroadenoma                         | X  X  X        X  X              X     X  X  X  X           X        X   |         18 |
      Fibroadenoma, Multiple               |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Squamous Cell Carcinoma              |                                                                          |          1 |
      Squamous Cell Papilloma              |                                     X                                    |          2 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Carcinoma, Metastatic, Pituitary     |                                                                          |            |
          Gland                            |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M|  44        |
      Leukemia Mononuclear                 |                         X                                                |          3 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Adenoma         |                                                                          |          1 |
      Carcinoma, Metastatic, Mammary Gland |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  24                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 7| 7| 7| 7| 7| 6| 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7| 4|            |
                             DAY ON TEST   | 3| 3| 9| 3| 3| 3| 3| 0| 7| 3| 0| 8| 3| 3| 3| 3| 3| 3| 3| 5| 3| 2| 3| 3| 8|            |
                                           | 5| 5| 9| 5| 6| 5| 5| 9| 4| 6| 2| 5| 6| 5| 5| 6| 5| 5| 5| 8| 6| 4| 6| 6| 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      |
   FISCHER 344 RATS 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                 |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 | X     X                 X                             X     X  X     X  X|         13 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X                                                        X         |          4 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                         X                                                |          1 |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                            +                                             |   3        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X                 X                                   X  X     X   |          9 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                         X                                                |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X                 X              X              X     X  X     X  X|         16 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  25                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 4| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 6| 7| 7|             
                             DAY ON TEST   | 2| 2| 4| 3| 3| 6| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3| 0| 3| 3| 3| 2| 3| 6| 3| 2|             
                                           | 9| 3| 8| 6| 6| 2| 5| 4| 6| 6| 5| 6| 1| 6| 5| 6| 9| 4| 4| 6| 7| 6| 7| 5| 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|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X     X                 X                 X     X         |             
                                            __________________________________________________________________________|             
   Mesentery                               |                            +                 +  +              +  +      |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                  +                                       |             
      Pharyngeal, Squamous Cell Papilloma  |                                  X                                       |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |    +                                                                     |             
      Schwannoma Malignant                 |    X                                                                     |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                               X         |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                               X         |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                               X         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                                         |             
      Pars Distalis, Adenoma               | X        X  X     X     X     X  X  X  X     X     X  X        X  X  X   |             
      Pars Distalis, Adenoma, Multiple     |                                                                          |             
      Pars Distalis, Leukemia Mononuclear  |                                                                X         |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  26                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 4| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 6| 7| 7|             
                             DAY ON TEST   | 2| 2| 4| 3| 3| 6| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3| 0| 3| 3| 3| 2| 3| 6| 3| 2|             
                                           | 9| 3| 8| 6| 6| 2| 5| 4| 6| 6| 5| 6| 1| 6| 5| 6| 9| 4| 4| 6| 7| 6| 7| 5| 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |       X                                                                  |             
      C-Cell, Adenoma                      |                               X                                          |             
      C-Cell, Carcinoma                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  M  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |       X        X                                                         |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
      Polyp Stromal                        |                                        X                       X         |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X              X                                   X     X         |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                      +                       +           +               |             
      Renal, Leukemia Mononuclear          |                                                          X               |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  +  +  +  M  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                                         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                         X     X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                  X     X         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X     X                 X                 X     X         |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                                         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Adenoma                              |                                                    X                     |             
      Carcinoma, Multiple                  |                                                                X         |             
      Fibroadenoma                         |             X                 X        X  X        X                 X  X|             
      Fibroadenoma, Multiple               |    X                    X  X     X              X                        |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Sebaceous Gland, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  27                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 4| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 6| 7| 7|             
                             DAY ON TEST   | 2| 2| 4| 3| 3| 6| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3| 0| 3| 3| 3| 2| 3| 6| 3| 2|             
                                           | 9| 3| 8| 6| 6| 2| 5| 4| 6| 6| 5| 6| 1| 6| 5| 6| 9| 4| 4| 6| 7| 6| 7| 5| 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                                         |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  M  +  +  +  +  M  M  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |                                                          X               |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X     X                                   X     X         |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                   +      |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                         X     X         |             
      Renal Tubule, Adenoma                |                                              X                           |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |       X        X     X                 X                 X     X         |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  28                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 4| 9| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 3| 3| 0| 5| 3| 3| 3| 3|            |
                                           | 5| 6| 0| 5| 6| 5| 4| 6| 5| 5| 5| 4| 9| 6| 5| 6| 4| 5| 5| 3| 5| 5| 6| 5| 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      |
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                                                             X            |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                       X  X     X   |         11 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                 +                       +|   7        |
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                                                          |   1        |
      Pharyngeal, Squamous Cell Papilloma  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          2 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                                                     |          2 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          2 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          1 |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
      Schwannoma Malignant                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                                        X            |          5 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                     X                       X  X         |          6 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                     X                       X            |          5 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Adenoma                              |                                                             X            |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  29                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 4| 9| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 3| 3| 0| 5| 3| 3| 3| 3|            |
                                           | 5| 6| 0| 5| 6| 5| 4| 6| 5| 5| 5| 4| 9| 6| 5| 6| 4| 5| 5| 3| 5| 5| 6| 5| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |    X                                                        X            |          4 |
      Pars Distalis, Adenoma               |       X     X  X              X  X     X                 X  X           X|         24 |
      Pars Distalis, Adenoma, Multiple     | X                       X                                         X      |          3 |
      Pars Distalis, Leukemia Mononuclear  |                                     X                                    |          2 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          2 |
      C-Cell, Adenoma                      |                X                                               X         |          3 |
      C-Cell, Carcinoma                    |                                        X                                 |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |    X                                                                     |          1 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Histiocytic Sarcoma                  |          X                                                               |          1 |
      Leukemia Mononuclear                 |                                                             X            |          3 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          2 |
      Polyp Stromal                        |                            X                                             |          3 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                       X            |          7 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +                                                                        |   4        |
      Renal, Leukemia Mononuclear          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  M  +  +  +  +  M  +  +  +  +  M  +  +  M  +  M  M  +  +  +  M  +  +  M|  38        |
      Leukemia Mononuclear                 |                                                             X            |          2 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                                        X  X         |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                       X  X         |          7 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                       X  X     X   |         11 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |    X                                                        X            |          4 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  30                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 4| 9| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 3| 3| 0| 5| 3| 3| 3| 3|            |
                                           | 5| 6| 0| 5| 6| 5| 4| 6| 5| 5| 5| 4| 9| 6| 5| 6| 4| 5| 5| 3| 5| 5| 6| 5| 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      |
   FISCHER 344 RATS 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               |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Adenoma                              |                                                                          |          1 |
      Carcinoma, Multiple                  |                                                                          |          1 |
      Fibroadenoma                         |             X  X     X  X           X        X        X        X         |         15 |
      Fibroadenoma, Multiple               |                                                 X                        |          6 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                                        X            |          2 |
      Sebaceous Gland, Carcinoma           |                                                                      X   |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                                        X            |          4 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|  45        |
      Leukemia Mononuclear                 |                                                                      X   |          2 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                       X  X     X   |         10 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          2 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                             X            |          1 |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                      +   |   1        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                       X  X     X   |          9 |
      Renal Tubule, Adenoma                |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                                                             X            |          2 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  31                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 4| 9| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 3| 3| 0| 5| 3| 3| 3| 3|            |
                                           | 5| 6| 0| 5| 6| 5| 4| 6| 5| 5| 5| 4| 9| 6| 5| 6| 4| 5| 5| 3| 5| 5| 6| 5| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Histiocytic Sarcoma                  |          X                                                               |          1 |
      Leukemia Mononuclear                 |    X                                X                       X  X     X   |         11 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  32                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 6| 6| 6| 7| 7| 5| 4| 7| 6| 6| 6| 6| 7| 7| 6| 7| 5| 7| 7| 6| 6| 5| 5|             
                             DAY ON TEST   | 8| 1| 0| 4| 0| 1| 3| 4| 7| 3| 4| 5| 9| 6| 3| 3| 8| 3| 9| 3| 3| 6| 0| 5| 2|             
                                           | 9| 0| 2| 0| 9| 3| 4| 7| 9| 4| 4| 2| 2| 1| 4| 4| 9| 4| 0| 4| 4| 8| 8| 3| 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|             
   FISCHER 344 RATS 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  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                    X                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | A  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                 X  X  X  X           X           X  X  X      |             
      Osteosarcoma, Metastatic, Spleen     |                                                       X                  |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                 +                        |             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                                 +                        |             
      Pharyngeal, Squamous Cell Papilloma  |                                                 X                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                    X                                   X      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                  X                                       |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X                          X  X                                       |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                              X      |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                    X  X                          X  X  X      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X     X                    X  X                          X     X      |             
      Osteosarcoma, Metastatic, Spleen     |                                                       X                  |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X     X                    X                             X            |             
      Osteosarcoma, Metastatic, Spleen     |                                                       X                  |             
      Pheochromocytoma Benign              |                                        X                                 |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  33                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 6| 6| 6| 7| 7| 5| 4| 7| 6| 6| 6| 6| 7| 7| 6| 7| 5| 7| 7| 6| 6| 5| 5|             
                             DAY ON TEST   | 8| 1| 0| 4| 0| 1| 3| 4| 7| 3| 4| 5| 9| 6| 3| 3| 8| 3| 9| 3| 3| 6| 0| 5| 2|             
                                           | 9| 0| 2| 0| 9| 3| 4| 7| 9| 4| 4| 2| 2| 1| 4| 4| 9| 4| 0| 4| 4| 8| 8| 3| 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
      Bilateral, Pheochromocytoma Benign   | X  X              X                             X        X     X  X      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                X                    X                                    |             
      Carcinoma                            |                                                       X                  |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                    X                                   X      |             
      Pars Distalis, Adenoma               |       X     X  X  X  X  X  X     X        X        X        X        X  X|             
      Pars Distalis, Adenoma, Multiple     | X                                            X                           |             
      Pars Distalis, Leukemia Mononuclear  |    X                             X                                       |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                                                                        |             
      Bilateral, C-Cell, Adenoma           |                                                                          |             
      C-Cell, Adenoma                      |                                           X                              |             
      C-Cell, Carcinoma                    |                                        X                                 |             
      Follicular Cell, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                         +                                                |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                  X                       X               |             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                  X                                X      |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                          X                                   X      |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Bilateral, Interstitial Cell, Adenoma|    X     X     X  X        X     X  X     X  X     X     X     X  X      |             
      Interstitial Cell, Adenoma           |       X                       X        X                    X            |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Leukemia Mononuclear                 |    X                          X  X  X                       X  X  X      |             
                                            __________________________________________________________________________|             
   Lymph Node                              |    +     +                    +  +              +              +         |             
      Deep Cervical, Leukemia Mononuclear  |                               X                                          |             
      Iliac, Leukemia Mononuclear          |          X                                                               |             
      Lumbar, Leukemia Mononuclear         |                               X  X                                       |             
      Pancreatic, Leukemia Mononuclear     |                                  X                             X         |             
      Renal, Leukemia Mononuclear          |    X                          X                 X                        |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  34                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 6| 6| 6| 7| 7| 5| 4| 7| 6| 6| 6| 6| 7| 7| 6| 7| 5| 7| 7| 6| 6| 5| 5|             
                             DAY ON TEST   | 8| 1| 0| 4| 0| 1| 3| 4| 7| 3| 4| 5| 9| 6| 3| 3| 8| 3| 9| 3| 3| 6| 0| 5| 2|             
                                           | 9| 0| 2| 0| 9| 3| 4| 7| 9| 4| 4| 2| 2| 1| 4| 4| 9| 4| 0| 4| 4| 8| 8| 3| 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|             
   FISCHER 344 RATS 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               |                                                                          |             
                                           |                                                                          |             
      Thoracic, Leukemia Mononuclear       |                               X                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M|             
      Leukemia Mononuclear                 | X  X     X                    X  X                          X  X  X      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                          X  X                             X  X      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                    X  X              X                 X      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                    X  X              X           X  X  X      |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                 X  X  X  X           X           X  X  X      |             
      Osteosarcoma                         |                                                       X                  |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  M|             
      Leukemia Mononuclear                 | X  X     X                    X  X                                X      |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroadenoma                         |                                                             X            |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Keratoacanthoma                      |                                           X                             X|             
      Leukemia Mononuclear                 |    X                          X                                   X      |             
      Squamous Cell Papilloma              |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                                                                          |             
      Subcutaneous Tissue, Leukemia        |                                                                          |             
          Mononuclear                      | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                       +                  |             
      Osteosarcoma, Metastatic, Spleen     |                                                       X                  |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                          X                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M|             
      Leukemia Mononuclear                 | X  X                                                                     |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                                                                          |             
      Alveolar/Bronchiolar Carcinoma       |                            X                                             |             
      Carcinoma, Metastatic, Thyroid Gland |                                        X                                 |             
      Leukemia Mononuclear                 | X  X     X                    X  X  X                       X     X      |             
      Osteosarcoma, Metastatic, Spleen     |                                                       X                  |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  35                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 6| 6| 6| 7| 7| 5| 4| 7| 6| 6| 6| 6| 7| 7| 6| 7| 5| 7| 7| 6| 6| 5| 5|             
                             DAY ON TEST   | 8| 1| 0| 4| 0| 1| 3| 4| 7| 3| 4| 5| 9| 6| 3| 3| 8| 3| 9| 3| 3| 6| 0| 5| 2|             
                                           | 9| 0| 2| 0| 9| 3| 4| 7| 9| 4| 4| 2| 2| 1| 4| 4| 9| 4| 0| 4| 4| 8| 8| 3| 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|             
   FISCHER 344 RATS 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                 |                                                                          |             
                                           |                                                                          |             
      Mediastinum, Osteosarcoma,           |                                                                          |             
          Metastatic, Spleen               |                                                       X                  |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Leukemia Mononuclear                 |    X                                                              X      |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                +         |             
      Carcinoma                            |                                                                X         |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                    X  X                          X  X  X      |             
      Lipoma                               |                                              X                           |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X                          X                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X  X     X                 X  X  X  X           X           X  X  X      |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  36                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 6| 7| 7| 6| 6| 7| 7| 5| 7| 3| 4| 7| 6| 7| 6| 6| 5| 7| 7| 3| 7| 5|            |
                             DAY ON TEST   | 3| 3| 4| 1| 3| 3| 2| 8| 1| 3| 7| 3| 9| 9| 3| 3| 3| 8| 5| 7| 1| 1| 5| 3| 8|            |
                                           | 4| 0| 0| 8| 4| 4| 3| 9| 0| 4| 4| 4| 1| 7| 4| 9| 4| 5| 3| 0| 4| 5| 4| 4| 4|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Sarcoma                              |                            X                                             |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  46        |
      Leukemia Mononuclear                 | X           X                                                           X|          5 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |    X                          X                                          |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  A  +  +  +  A  A  +  +  +  +  +  A  +  +  A  +  +|  42        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  A  +  +|  45        |
      Leukemia Mononuclear                 | X  X                                               X                     |          4 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X     X  X  X     X     X  X        X  X     X  X  X     X        X|         27 |
      Osteosarcoma, Metastatic, Spleen     |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |             +                          +                             +   |   4        |
      Sarcoma                              |                                        X                                 |          1 |
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                                                      +   |   2        |
      Pharyngeal, Squamous Cell Papilloma  |                                                                      X   |          2 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                                     X               |          7 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                                                     |          2 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                                                     |          5 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                         X        X                  |          5 |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                          +               |   1        |
      Squamous Cell Papilloma              |                                                          X               |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X        X           X     X              X     X  X        X        X|         18 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                    X                    X     X                    X|         11 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  37                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 6| 7| 7| 6| 6| 7| 7| 5| 7| 3| 4| 7| 6| 7| 6| 6| 5| 7| 7| 3| 7| 5|            |
                             DAY ON TEST   | 3| 3| 4| 1| 3| 3| 2| 8| 1| 3| 7| 3| 9| 9| 3| 3| 3| 8| 5| 7| 1| 1| 5| 3| 8|            |
                                           | 4| 0| 0| 8| 4| 4| 3| 9| 0| 4| 4| 4| 1| 7| 4| 9| 4| 5| 3| 0| 4| 5| 4| 4| 4|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Osteosarcoma, Metastatic, Spleen     |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X        X           X                    X     X                    X|         10 |
      Osteosarcoma, Metastatic, Spleen     |                                                                          |          1 |
      Pheochromocytoma Benign              |             X  X  X                                            X        X|          6 |
      Bilateral, Pheochromocytoma Benign   |                                                                          |          7 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                 X                        |          3 |
      Carcinoma                            |                                                                X         |          2 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                                                    X|          5 |
      Pars Distalis, Adenoma               |          X     X  X     X  X        X           X     X     X  X         |         23 |
      Pars Distalis, Adenoma, Multiple     |                                                                          |          2 |
      Pars Distalis, Leukemia Mononuclear  |                                                       X                  |          3 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Bilateral, C-Cell, Adenoma           |             X  X                                                         |          2 |
      C-Cell, Adenoma                      |                                                                          |          1 |
      C-Cell, Carcinoma                    |                                                             X            |          2 |
      Follicular Cell, Carcinoma           |                                                                      X   |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                                                     |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Adenoma                              |                               X                                          |          3 |
      Leukemia Mononuclear                 |    X                    X                                               X|          4 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                    X                                                |          4 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                                                     |          4 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                               X                                          |          1 |
      Bilateral, Interstitial Cell, Adenoma| X  X        X  X  X  X  X  X     X        X  X  X  X                 X   |         27 |
      Interstitial Cell, Adenoma           |       X                                X                 X  X           X|          9 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  38                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 6| 7| 7| 6| 6| 7| 7| 5| 7| 3| 4| 7| 6| 7| 6| 6| 5| 7| 7| 3| 7| 5|            |
                             DAY ON TEST   | 3| 3| 4| 1| 3| 3| 2| 8| 1| 3| 7| 3| 9| 9| 3| 3| 3| 8| 5| 7| 1| 1| 5| 3| 8|            |
                                           | 4| 0| 0| 8| 4| 4| 3| 9| 0| 4| 4| 4| 1| 7| 4| 9| 4| 5| 3| 0| 4| 5| 4| 4| 4|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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                     |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 | X  X        X           X     X              X     X  X  X              X|         17 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +        +                                                            |   9        |
      Deep Cervical, Leukemia Mononuclear  |                                                                          |          1 |
      Iliac, Leukemia Mononuclear          |                                                                          |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          2 |
      Pancreatic, Leukemia Mononuclear     |    X        X                                                            |          4 |
      Renal, Leukemia Mononuclear          | X                                                                        |          4 |
      Thoracic, Leukemia Mononuclear       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  M  M  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +|  44        |
      Leukemia Mononuclear                 |    X        X                 X                       X  X     X        X|         15 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 | X  X        X           X        X                 X  X  X              X|         14 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 | X  X        X           X     X  X                    X        X        X|         16 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 | X  X        X           X                    X     X  X                 X|         17 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X     X  X  X     X     X  X        X  X     X  X  X     X        X|         27 |
      Osteosarcoma                         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Leukemia Mononuclear                 | X  X                                               X     X              X|         11 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +  +|  46        |
      Fibroadenoma                         |                                                                      X   |          2 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Keratoacanthoma                      |          X                                                               |          3 |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Squamous Cell Papilloma              | X     X                                                                  |          2 |
      Subcutaneous Tissue, Fibroma         |                            X                                             |          1 |
      Subcutaneous Tissue, Leukemia        |                                                                          |            |
          Mononuclear                      |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  39                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 6| 7| 7| 6| 6| 7| 7| 5| 7| 3| 4| 7| 6| 7| 6| 6| 5| 7| 7| 3| 7| 5|            |
                             DAY ON TEST   | 3| 3| 4| 1| 3| 3| 2| 8| 1| 3| 7| 3| 9| 9| 3| 3| 3| 8| 5| 7| 1| 1| 5| 3| 8|            |
                                           | 4| 0| 0| 8| 4| 4| 3| 9| 0| 4| 4| 4| 1| 7| 4| 9| 4| 5| 3| 0| 4| 5| 4| 4| 4|            |
 _____________________________________________________________________________________________________________________|     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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
      Osteosarcoma, Metastatic, Spleen     |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                               X                                         X|          4 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  M  +  M  M  +  M  +  +  +  +  +  +  M  +  M|  40        |
      Leukemia Mononuclear                 |    X                                                                     |          3 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Adenoma         |                            X                                X            |          2 |
      Alveolar/Bronchiolar Carcinoma       |                                                                          |          1 |
      Carcinoma, Metastatic, Thyroid Gland |                                                             X            |          2 |
      Leukemia Mononuclear                 |    X        X           X     X  X        X  X     X     X              X|         18 |
      Osteosarcoma, Metastatic, Spleen     |                                                                          |          1 |
      Mediastinum, Osteosarcoma,           |                                                                          |            |
          Metastatic, Spleen               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                               X                    X|          5 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                              X                           |          2 |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                         +|   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   1        |
      Carcinoma                            |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X        X  X        X     X              X     X  X  X     X        X|         20 |
      Lipoma                               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                    X                                               X|          6 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X     X  X  X     X     X  X        X  X     X  X  X     X        X|         27 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  40                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 3| 5| 6| 7| 5| 4| 6| 7| 6| 7| 7| 7| 6| 7| 5| 7| 6| 7| 5| 2| 6| 5| 6|             
                             DAY ON TEST   | 0| 3| 0| 8| 1| 3| 9| 1| 5| 3| 3| 3| 3| 3| 3| 2| 6| 3| 3| 3| 8| 4| 6| 3| 9|             
                                           | 1| 4| 8| 4| 9| 4| 6| 6| 4| 4| 4| 4| 4| 4| 1| 0| 0| 4| 7| 4| 4| 4| 8| 8| 3|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                         X|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  +  A  A  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hepatocellular Adenoma               |                                                 X                 X      |             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |    X           X  X     X     X     X        X     X  X     X           X|             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                             +  +         |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                         X|             
      Duct, Carcinoma                      |    X                                                                     |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                             X           X|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                    X  X     X           X|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                    X                    X|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                    X                    X|             
      Pheochromocytoma Malignant           |                                        X                                 |             
      Pheochromocytoma Benign              |    X                                   X                 X  X            |             
      Bilateral, Pheochromocytoma Benign   |                                  X                                       |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                 X                        |             
      Carcinoma                            |                                     X                                    |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  41                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 3| 5| 6| 7| 5| 4| 6| 7| 6| 7| 7| 7| 6| 7| 5| 7| 6| 7| 5| 2| 6| 5| 6|             
                             DAY ON TEST   | 0| 3| 0| 8| 1| 3| 9| 1| 5| 3| 3| 3| 3| 3| 3| 2| 6| 3| 3| 3| 8| 4| 6| 3| 9|             
                                           | 1| 4| 8| 4| 9| 4| 6| 6| 4| 4| 4| 4| 4| 4| 1| 0| 0| 4| 7| 4| 4| 4| 8| 8| 3|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Pars Distalis, Adenoma               |          X  X           X  X     X     X     X  X  X     X        X      |             
      Pars Distalis, Adenoma, Multiple     |                                     X                                    |             
      Pars Distalis, Leukemia Mononuclear  |                                                                         X|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |    X                                         X           X               |             
      Follicular Cell, Carcinoma           |                X                                                         |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Peritoneum                              |                                                                          |             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                 X                        |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant               |                                                                          |             
      Bilateral, Interstitial Cell, Adenoma| X  X           X  X           X  X  X  X           X     X           X  X|             
      Interstitial Cell, Adenoma           |                            X                 X              X            |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |                   X     X     X                    X  X                 X|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                  +                    +     +        +  +|             
      Pancreatic, Leukemia Mononuclear     |                                                       X                 X|             
      Renal, Leukemia Mononuclear          |                                                             X            |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  M  +  M  M  M  +  M  +  +  M  +  +  +  M  +  M  +  M  +  +  +  M  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |                               X                       X     X           X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X     X                    X                    X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  42                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 3| 5| 6| 7| 5| 4| 6| 7| 6| 7| 7| 7| 6| 7| 5| 7| 6| 7| 5| 2| 6| 5| 6|             
                             DAY ON TEST   | 0| 3| 0| 8| 1| 3| 9| 1| 5| 3| 3| 3| 3| 3| 3| 2| 6| 3| 3| 3| 8| 4| 6| 3| 9|             
                                           | 1| 4| 8| 4| 9| 4| 6| 6| 4| 4| 4| 4| 4| 4| 1| 0| 0| 4| 7| 4| 4| 4| 8| 8| 3|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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               |                                                                          |             
                                           |                                                                          |             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |    X                    X     X                       X                 X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |                   X     X     X     X              X  X     X           X|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |    X           X  X     X     X     X        X     X  X     X           X|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  M  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |                                                                         X|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroadenoma                         |                                                          X               |             
      Fibroadenoma, Multiple               |                            X                                             |             
      Fibroma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Keratoacanthoma                      |                                                       X                  |             
      Leukemia Mononuclear                 |                                                                          |             
      Squamous Cell Papilloma              |                            X                                             |             
      Pinna, Schwannoma Benign             |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                                                                          |             
      Subcutaneous Tissue, Fibrosarcoma    |                                                 X                        |             
      Subcutaneous Tissue, Sarcoma         |                                                                   X      |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         | +                                                                        |             
      Histiocytic Sarcoma                  | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  A  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                                                                          |             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |                   X     X     X     X              X  X     X           X|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  43                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 3| 5| 6| 7| 5| 4| 6| 7| 6| 7| 7| 7| 6| 7| 5| 7| 6| 7| 5| 2| 6| 5| 6|             
                             DAY ON TEST   | 0| 3| 0| 8| 1| 3| 9| 1| 5| 3| 3| 3| 3| 3| 3| 2| 6| 3| 3| 3| 8| 4| 6| 3| 9|             
                                           | 1| 4| 8| 4| 9| 4| 6| 6| 4| 4| 4| 4| 4| 4| 1| 0| 0| 4| 7| 4| 4| 4| 8| 8| 3|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                 |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |    X                    X     X                    X                    X|             
      Renal Tubule, Adenoma                |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                         X|             
      Transitional Epithelium, Papilloma   |                                     X                                    |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  | X                                                                        |             
      Leukemia Mononuclear                 |    X           X  X     X     X     X        X     X  X     X           X|             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  44                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 5| 7| 7| 6| 6| 7| 6| 7| 6| 6| 7| 6| 6| 5| 7| 6| 7| 6| 7| 7| 5| 3|            |
                             DAY ON TEST   | 3| 9| 1| 1| 0| 3| 0| 2| 3| 7| 3| 4| 0| 1| 3| 9| 8| 1| 1| 2| 1| 3| 3| 4| 5|            |
                                           | 4| 5| 8| 8| 7| 4| 0| 6| 4| 1| 4| 0| 7| 4| 9| 2| 2| 3| 5| 3| 7| 4| 4| 9| 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      |
   FISCHER 344 RATS 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        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                   X                                 |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A|  44        |
      Leukemia Mononuclear                 |                                     X                    X               |          3 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                                     X                                    |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  A  +  +  A  +  +  A  +  +  A  +  A  +  +  +  +  +  +  A|  39        |
      Leukemia Mononuclear                 |                X                                                         |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A|  44        |
      Leukemia Mononuclear                 |    X           X                    X                                    |          3 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hepatocellular Adenoma               |                                  X                                       |          3 |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X     X     X  X     X  X  X     X     X  X  X  X  X      |         26 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +           +                                         +                  |   5        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                                    |          4 |
      Duct, Carcinoma                      |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                     X     X                              |          2 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                                                     |          3 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                                X                                    |          2 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X  X        X     X              X  X  X     X           X            |         14 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X  X        X     X                 X        X        X  X            |         10 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X        X     X              X  X        X           X            |          9 |
      Pheochromocytoma Malignant           |                                                                          |          1 |
      Pheochromocytoma Benign              |    X  X        X     X                 X                       X         |         10 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  45                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 5| 7| 7| 6| 6| 7| 6| 7| 6| 6| 7| 6| 6| 5| 7| 6| 7| 6| 7| 7| 5| 3|            |
                             DAY ON TEST   | 3| 9| 1| 1| 0| 3| 0| 2| 3| 7| 3| 4| 0| 1| 3| 9| 8| 1| 1| 2| 1| 3| 3| 4| 5|            |
                                           | 4| 5| 8| 8| 7| 4| 0| 6| 4| 1| 4| 0| 7| 4| 9| 2| 2| 3| 5| 3| 7| 4| 4| 9| 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      |
   FISCHER 344 RATS 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                   |                                                                          |            |
                                           |                                                                          |            |
      Bilateral, Pheochromocytoma Benign   |             X           X                                                |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              | X                                X     X                                 |          4 |
      Carcinoma                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Adenoma                              |                                                                      X   |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                           X     X                        |          2 |
      Pars Distalis, Adenoma               |          X     X  X        X     X                          X        X   |         18 |
      Pars Distalis, Adenoma, Multiple     |                                                                          |          1 |
      Pars Distalis, Leukemia Mononuclear  |                X     X                                                   |          3 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      C-Cell, Adenoma                      |       X        X                                            X            |          6 |
      Follicular Cell, Carcinoma           |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Peritoneum                              |                                                          +               |   1        |
      Mesothelioma Malignant               |                                                          X               |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                                                     |          1 |
      Mesothelioma Malignant               |                                              X           X               |          2 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
      Leukemia Mononuclear                 |    X                                X                                    |          2 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                X  X  X                              |          4 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X                 X              X                                    |          3 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                     X                                    |          1 |
      Mesothelioma Malignant               |                                              X           X               |          2 |
      Bilateral, Interstitial Cell, Adenoma| X  X  X                 X     X              X     X     X  X  X  X      |         23 |
      Interstitial Cell, Adenoma           |                X           X     X  X  X  X     X                        |         10 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  46                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 5| 7| 7| 6| 6| 7| 6| 7| 6| 6| 7| 6| 6| 5| 7| 6| 7| 6| 7| 7| 5| 3|            |
                             DAY ON TEST   | 3| 9| 1| 1| 0| 3| 0| 2| 3| 7| 3| 4| 0| 1| 3| 9| 8| 1| 1| 2| 1| 3| 3| 4| 5|            |
                                           | 4| 5| 8| 8| 7| 4| 0| 6| 4| 1| 4| 0| 7| 4| 9| 2| 2| 3| 5| 3| 7| 4| 4| 9| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |    X  X        X     X              X  X  X     X           X            |         15 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                +              +        +                                 |   8        |
      Pancreatic, Leukemia Mononuclear     |                X                                                         |          3 |
      Renal, Leukemia Mononuclear          |                                        X                                 |          2 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  M  +  M  +  +  +  +  +  M  +  +  +  M  M  +  M  +  +  +  +  +  +  +|  34        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X           X     X              X  X                 X  X            |         11 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  48        |
      Leukemia Mononuclear                 |    X  X        X                    X  X  X                              |         10 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X           X                    X  X  X           X     X  X         |         13 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X     X              X  X  X     X     X  X  X            |         19 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X     X     X  X     X  X  X     X     X  X  X  X  X      |         26 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  M|  44        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X           X                    X     X                              |          5 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  47        |
      Fibroadenoma                         |                                                                X         |          2 |
      Fibroadenoma, Multiple               |                                                                          |          1 |
      Fibroma                              |             X                                                        X   |          2 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Keratoacanthoma                      |       X                                                                  |          2 |
      Leukemia Mononuclear                 |                X                                         X               |          2 |
      Squamous Cell Papilloma              |                                                                          |          1 |
      Pinna, Schwannoma Benign             |                         X                                                |          1 |
      Subcutaneous Tissue, Fibroma         |                                                    X                     |          1 |
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |          1 |
      Subcutaneous Tissue, Sarcoma         |             X                                                            |          2 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  47                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 5| 7| 7| 6| 6| 7| 6| 7| 6| 6| 7| 6| 6| 5| 7| 6| 7| 6| 7| 7| 5| 3|            |
                             DAY ON TEST   | 3| 9| 1| 1| 0| 3| 0| 2| 3| 7| 3| 4| 0| 1| 3| 9| 8| 1| 1| 2| 1| 3| 3| 4| 5|            |
                                           | 4| 5| 8| 8| 7| 4| 0| 6| 4| 1| 4| 0| 7| 4| 9| 2| 2| 3| 5| 3| 7| 4| 4| 9| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |    X                                            X                        |          3 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  M|  44        |
      Leukemia Mononuclear                 |                      X                 X                    X            |          3 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Adenoma         |                                                    X                     |          1 |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X     X     X        X  X  X     X     X  X  X            |         20 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                      X                 X                    X            |          3 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                     +                                    |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X           X     X        X     X  X  X           X  X  X     X      |         16 |
      Renal Tubule, Adenoma                |                      X                 X                    X            |          3 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |    X  X                                                                  |          3 |
      Transitional Epithelium, Papilloma   |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X     X     X  X     X  X  X     X     X  X  X  X  X      |         26 |
      Mesothelioma Malignant               |                                              X           X               |          2 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  48                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 4| 7| 6| 7| 7| 5| 7| 7| 7| 7| 7| 7| 6| 6| 6| 4| 7| 7| 5| 5| 6| 5|             
                             DAY ON TEST   | 7| 3| 5| 9| 3| 9| 0| 3| 0| 3| 3| 3| 3| 3| 1| 6| 2| 8| 6| 0| 3| 9| 9| 6| 9|             
                                           | 1| 4| 6| 6| 4| 6| 4| 4| 9| 4| 4| 4| 4| 4| 3| 5| 9| 8| 7| 7| 4| 0| 0| 9| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                         X|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                         X|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                                     X|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                            X              X                              |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                         X|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Leukemia Mononuclear                 |                            X              X                             X|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X  X     X  X  X  X  X     X  X     X  X     X     X     X  X     X|             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                 +                        |             
      Lipoma                               |                                                                          |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                               +                                          |             
      Pharyngeal, Squamous Cell Papilloma  |                               X                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X     X                                X        X      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                                                |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                 X              X              X|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                                X               |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X     X  X              X              X     X  X     X|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                X  X     X        X        X              X     X        X|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
      Leukemia Mononuclear                 |                X  X     X        X        X                    X        X|             
      Pheochromocytoma Benign              | X                    X                                         X         |             
      Bilateral, Pheochromocytoma Benign   |                   X                          X     X                     |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              | X                 X           X  X                                       |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  49                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 4| 7| 6| 7| 7| 5| 7| 7| 7| 7| 7| 7| 6| 6| 6| 4| 7| 7| 5| 5| 6| 5|             
                             DAY ON TEST   | 7| 3| 5| 9| 3| 9| 0| 3| 0| 3| 3| 3| 3| 3| 1| 6| 2| 8| 6| 0| 3| 9| 9| 6| 9|             
                                           | 1| 4| 6| 6| 4| 6| 4| 4| 9| 4| 4| 4| 4| 4| 3| 5| 9| 8| 7| 7| 4| 0| 0| 9| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                 X              X     X         |             
      Pars Distalis, Adenoma               |    X  X              X                 X  X           X              X  X|             
      Pars Distalis, Adenoma, Multiple     |                                     X                                    |             
      Pars Distalis, Leukemia Mononuclear  |                   X                                               X      |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                                                |             
      C-Cell, Adenoma                      |                                        X     X                           |             
      Follicular Cell, Carcinoma           |                      X                                                   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                X  X     X                                         X     X|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                        X                                 |             
      Leukemia Mononuclear                 |                         X                                                |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X     X                                         X      |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X                                                      |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                X        X                                         X     X|             
      Mesothelioma Malignant               |                                                                          |             
      Bilateral, Interstitial Cell, Adenoma| X  X        X  X  X  X     X  X  X  X  X     X     X     X     X     X  X|             
      Interstitial Cell, Adenoma           |                         X                       X           X            |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X     X  X     X        X        X     X     X  X     X|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                   +           +           +        +        +     +     +|             
      Pancreatic, Leukemia Mononuclear     |                   X                                               X     X|             
      Renal, Leukemia Mononuclear          |                                           X        X                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  M  +  +  +|             
      Leukemia Mononuclear                 |                X  X     X        X        X              X        X     X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X  X     X        X                    X  X     X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X        X     X        X              X     X  X     X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X     X  X     X        X              X     X  X     X|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  50                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 4| 7| 6| 7| 7| 5| 7| 7| 7| 7| 7| 7| 6| 6| 6| 4| 7| 7| 5| 5| 6| 5|             
                             DAY ON TEST   | 7| 3| 5| 9| 3| 9| 0| 3| 0| 3| 3| 3| 3| 3| 1| 6| 2| 8| 6| 0| 3| 9| 9| 6| 9|             
                                           | 1| 4| 6| 6| 4| 6| 4| 4| 9| 4| 4| 4| 4| 4| 3| 5| 9| 8| 7| 7| 4| 0| 0| 9| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X  X     X  X  X  X  X     X  X     X  X     X     X     X  X     X|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X     X                 X              X     X         |             
      Thymoma Benign                       |                      X                                                   |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  +|             
      Adenoma                              |                                                                          |             
      Fibroadenoma                         |                      X                                                   |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                    X                     |             
      Keratoacanthoma                      |                               X                                          |             
      Leukemia Mononuclear                 |                                           X              X        X     X|             
      Squamous Cell Papilloma              |                      X                                                   |             
      Pinna, Schwannoma Malignant          |                                                                          |             
      Sebaceous Gland, Adenoma             |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                      X              X              X                     |             
      Subcutaneous Tissue, Myxoma          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Turbinate, Chondroma                 |                                                             X            |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Glioma Malignant                     |                                                                          |             
      Leukemia Mononuclear                 |                         X                 X                       X     X|             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  M  M|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X  X     X  X     X  X        X     X        X     X     X  X     X|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                   X     X                 X                             X|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leiomyosarcoma                       |    X                                                                     |             
      Leukemia Mononuclear                 |                                                                         X|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  51                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 5| 4| 7| 6| 7| 7| 5| 7| 7| 7| 7| 7| 7| 6| 6| 6| 4| 7| 7| 5| 5| 6| 5|             
                             DAY ON TEST   | 7| 3| 5| 9| 3| 9| 0| 3| 0| 3| 3| 3| 3| 3| 1| 6| 2| 8| 6| 0| 3| 9| 9| 6| 9|             
                                           | 1| 4| 6| 6| 4| 6| 4| 4| 9| 4| 4| 4| 4| 4| 3| 5| 9| 8| 7| 7| 4| 0| 0| 9| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                        +                                 |             
      Carcinoma                            |                                        X                                 |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X     X  X     X  X     X  X              X     X     X  X     X|             
      Renal Tubule, Adenoma                |                                                                          |             
      Renal Tubule, Carcinoma              |                      X                                                   |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                 X              X               |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X  X     X  X  X  X  X     X  X     X  X     X     X     X  X     X|             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  52                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 5| 6| 6| 7| 6| 5| 7| 6| 7| 4| 2| 7| 7| 7| 5| 5| 7| 6| 7| 7| 7| 5| 6|            |
                             DAY ON TEST   | 4| 3| 9| 6| 2| 2| 1| 8| 0| 7| 2| 2| 6| 1| 3| 3| 2| 2| 0| 4| 0| 3| 0| 9| 8|            |
                                           | 4| 4| 1| 8| 4| 0| 9| 9| 3| 1| 3| 0| 6| 2| 4| 4| 8| 7| 8| 3| 3| 4| 3| 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      |
   FISCHER 344 RATS 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        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |          X                    X                                      X   |          4 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                      X                                                   |          3 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +|  46        |
      Leukemia Mononuclear                 |                         X                                                |          3 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X           X  X     X        X                                 |          6 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  A  +  A  +  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +|  44        |
      Leukemia Mononuclear                 |          X                                                           X   |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  A  +  +  +  +  +|  45        |
      Leukemia Mononuclear                 |          X           X  X                                                |          6 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X  X     X     X  X     X        X  X  X        X  X  X     X  X   |         32 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                        +                                +|   3        |
      Lipoma                               |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                                                          |   1        |
      Pharyngeal, Squamous Cell Papilloma  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X  X           X  X     X                             X     X  X   |         12 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                    X                                          |          3 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X        X           X        X        X     X              X     X  X   |         13 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                    X                                   X  X   |          6 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X  X           X        X        X  X              X  X     X  X   |         18 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X  X     X     X  X     X        X  X              X  X        X   |         19 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |       X  X     X     X  X     X        X  X              X  X        X   |         18 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  53                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 5| 6| 6| 7| 6| 5| 7| 6| 7| 4| 2| 7| 7| 7| 5| 5| 7| 6| 7| 7| 7| 5| 6|            |
                             DAY ON TEST   | 4| 3| 9| 6| 2| 2| 1| 8| 0| 7| 2| 2| 6| 1| 3| 3| 2| 2| 0| 4| 0| 3| 0| 9| 8|            |
                                           | 4| 4| 1| 8| 4| 0| 9| 9| 3| 1| 3| 0| 6| 2| 4| 4| 8| 7| 8| 3| 3| 4| 3| 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      |
   FISCHER 344 RATS 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                   |                                                                          |            |
                                           |                                                                          |            |
      Pheochromocytoma Benign              |                                           X  X                 X         |          6 |
      Bilateral, Pheochromocytoma Benign   |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          4 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                    X                          X  X     X  X   |         10 |
      Pars Distalis, Adenoma               | X  X        X              X  X  X        X     X  X        X            |         18 |
      Pars Distalis, Adenoma, Multiple     |                                                                          |          1 |
      Pars Distalis, Leukemia Mononuclear  |                X     X  X              X                                 |          6 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                      X   |          2 |
      C-Cell, Adenoma                      |                                                                      X   |          3 |
      Follicular Cell, Carcinoma           |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                      X   |          6 |
      Mesothelioma Malignant               |                                                    X                     |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Adenoma                              |                                                                          |          1 |
      Leukemia Mononuclear                 |          X                    X                                          |          3 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                    X        X                 X           X   |          8 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                    X                          X           X   |          5 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                      X                                      X            |          6 |
      Mesothelioma Malignant               |                                                    X                     |          1 |
      Bilateral, Interstitial Cell, Adenoma|    X  X  X     X  X     X  X           X  X  X           X     X  X  X  X|         32 |
      Interstitial Cell, Adenoma           |             X        X        X  X                    X                  |          8 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X  X     X     X  X     X        X  X  X        X  X  X     X  X   |         25 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +                                      +                                 |   9        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  54                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 5| 6| 6| 7| 6| 5| 7| 6| 7| 4| 2| 7| 7| 7| 5| 5| 7| 6| 7| 7| 7| 5| 6|            |
                             DAY ON TEST   | 4| 3| 9| 6| 2| 2| 1| 8| 0| 7| 2| 2| 6| 1| 3| 3| 2| 2| 0| 4| 0| 3| 0| 9| 8|            |
                                           | 4| 4| 1| 8| 4| 0| 9| 9| 3| 1| 3| 0| 6| 2| 4| 4| 8| 7| 8| 3| 3| 4| 3| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          3 |
      Renal, Leukemia Mononuclear          | X                                      X                                 |          4 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  M  M  M  +  +  +  +  +  M  +  +  +  M  +  M  +  +  +  +  +  M  +|  39        |
      Leukemia Mononuclear                 | X     X                 X     X        X  X              X  X     X      |         17 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |          X           X  X     X        X     X              X        X   |         15 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X  X           X  X     X        X  X              X           X   |         17 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X  X     X     X  X     X        X  X  X           X  X     X  X   |         23 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X  X     X     X  X     X        X  X  X        X  X  X     X  X   |         32 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +|  46        |
      Leukemia Mononuclear                 |       X  X           X        X        X                 X               |         11 |
      Thymoma Benign                       |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Adenoma                              |                                                          X               |          1 |
      Fibroadenoma                         |                X                                                         |          2 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basal Cell Adenoma                   |                                                                          |          1 |
      Keratoacanthoma                      |                                           X                              |          2 |
      Leukemia Mononuclear                 |                               X                                          |          5 |
      Squamous Cell Papilloma              |                                                                          |          1 |
      Pinna, Schwannoma Malignant          | X                                                                        |          1 |
      Sebaceous Gland, Adenoma             |                            X                                             |          1 |
      Subcutaneous Tissue, Fibroma         |                                                                          |          3 |
      Subcutaneous Tissue, Myxoma          |                                     X                                    |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Turbinate, Chondroma                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Glioma Malignant                     |                                  X                                       |          1 |
      Leukemia Mononuclear                 |          X                             X                 X  X     X  X   |         10 |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                                   +     +|   2        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  55                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 5| 6| 6| 7| 6| 5| 7| 6| 7| 4| 2| 7| 7| 7| 5| 5| 7| 6| 7| 7| 7| 5| 6|            |
                             DAY ON TEST   | 4| 3| 9| 6| 2| 2| 1| 8| 0| 7| 2| 2| 6| 1| 3| 3| 2| 2| 0| 4| 0| 3| 0| 9| 8|            |
                                           | 4| 4| 1| 8| 4| 0| 9| 9| 3| 1| 3| 0| 6| 2| 4| 4| 8| 7| 8| 3| 3| 4| 3| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 NERVOUS SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                   +  +  +|   3        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  M  +|  41        |
      Leukemia Mononuclear                 | X                                                           X     X      |          3 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X  X     X     X  X     X        X  X  X        X  X  X     X  X   |         28 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X  X     X     X  X     X                          X  X     X  X   |         14 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leiomyosarcoma                       |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                         +|   1        |
      Carcinoma                            |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   1        |
      Carcinoma                            |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X     X  X     X     X  X     X        X  X  X           X  X     X  X   |         26 |
      Renal Tubule, Adenoma                |                            X                 X                           |          2 |
      Renal Tubule, Carcinoma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                    X        X                 X           X   |          8 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 | X  X  X  X     X     X  X     X        X  X  X        X  X  X     X  X   |         32 |
      Mesothelioma Malignant               |                                                    X                     |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  56                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 5| 6| 5| 7| 5| 5| 7| 5| 6| 5| 5| 5| 5| 5| 6| 5| 6| 5| 6| 6| 5| 5|             
                             DAY ON TEST   | 0| 6| 3| 6| 4| 8| 1| 5| 4| 3| 8| 8| 8| 9| 3| 4| 7| 1| 8| 5| 6| 5| 8| 8| 8|             
                                           | 2| 8| 4| 7| 3| 8| 9| 5| 7| 4| 7| 1| 6| 0| 8| 6| 2| 6| 7| 1| 3| 2| 0| 4| 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|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                         X|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  A  +  +  +  +  +  A  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +|             
      Leukemia Mononuclear                 |                                              X                           |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                          X|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  A  +  +  +  +  A  A  A  +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  A  +  +  +  +  A  A  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +  A  +|             
      Leukemia Mononuclear                 |                                              X                           |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +|             
      Leukemia Mononuclear                 |                            X              X  X              X           X|             
                                            __________________________________________________________________________|             
   Mesentery                               |          +                    +                                          |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                                                          |             
      Pharyngeal, Squamous Cell Papilloma  |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X                          X|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X              X           X|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X              X           X|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X              X            |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                             X           X|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                             X           X|             
      Pheochromocytoma Malignant           |                               X                                          |             
      Pheochromocytoma Benign              |       X        X        X  X                       X  X                  |             
      Bilateral, Pheochromocytoma Benign   |                   X                          X                           |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                            X                             X        X      |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  57                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 5| 6| 5| 7| 5| 5| 7| 5| 6| 5| 5| 5| 5| 5| 6| 5| 6| 5| 6| 6| 5| 5|             
                             DAY ON TEST   | 0| 6| 3| 6| 4| 8| 1| 5| 4| 3| 8| 8| 8| 9| 3| 4| 7| 1| 8| 5| 6| 5| 8| 8| 8|             
                                           | 2| 8| 4| 7| 3| 8| 9| 5| 7| 4| 7| 1| 6| 0| 8| 6| 2| 6| 7| 1| 3| 2| 0| 4| 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|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                                                             X           X|             
      Pars Distalis, Adenoma               |       X  X                    X        X  X              X  X  X  X      |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X                           |             
      C-Cell, Adenoma                      |                                                                          |             
      Follicular Cell, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X              X            |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                   X                                                      |             
      Leukemia Mononuclear                 |                                                             X            |             
      Bilateral, Adenoma                   |                                              X                           |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                             X            |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                             X            |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
      Bilateral, Interstitial Cell, Adenoma| X  X  X  X  X  X  X  X  X  X     X  X  X     X  X  X  X     X     X     X|             
      Interstitial Cell, Adenoma           |                                                          X     X     X   |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X              X           X|             
                                            __________________________________________________________________________|             
   Lymph Node                              |       +                       +           +  +     +     +  +           +|             
      Leukemia Mononuclear                 |                                              X              X            |             
      Lumbar, Leukemia Mononuclear         |                                              X              X           X|             
      Pancreatic, Leukemia Mononuclear     |                                              X                           |             
      Renal, Leukemia Mononuclear          |                                           X  X              X           X|             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  M  +  +  +  +  M  +  +  M  M  M  +  +  +  M  +  M  M  +  M  M  M  +|             
      Leukemia Mononuclear                 |                                           X                 X           X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X              X           X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                            X              X  X              X           X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X              X           X|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                            X              X  X              X           X|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  58                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 5| 6| 5| 7| 5| 5| 7| 5| 6| 5| 5| 5| 5| 5| 6| 5| 6| 5| 6| 6| 5| 5|             
                             DAY ON TEST   | 0| 6| 3| 6| 4| 8| 1| 5| 4| 3| 8| 8| 8| 9| 3| 4| 7| 1| 8| 5| 6| 5| 8| 8| 8|             
                                           | 2| 8| 4| 7| 3| 8| 9| 5| 7| 4| 7| 1| 6| 0| 8| 6| 2| 6| 7| 1| 3| 2| 0| 4| 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|             
   FISCHER 344 RATS 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               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  M  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X                          X|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Carcinoma                 |                   X                                                      |             
      Keratoacanthoma                      |                            X                                             |             
      Leukemia Mononuclear                 |                                           X  X              X           X|             
      Subcutaneous Tissue, Lipoma          |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
      Sarcoma                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Glioma Malignant                     |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  M  +  M  +  +  +  M  +  +  M  +  M  +  +  +  +  +  M  M  +  +  M|             
      Leukemia Mononuclear                 |                                              X                           |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                                                                          |             
      Leukemia Mononuclear                 |                                           X  X              X           X|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                          X|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                              X                           |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X  X              X            |             
      Renal Tubule, Adenoma                |                            X                       X  X                  |             
      Renal Tubule, Carcinoma              |                               X                          X               |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  59                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 5| 6| 5| 7| 5| 5| 7| 5| 6| 5| 5| 5| 5| 5| 6| 5| 6| 5| 6| 6| 5| 5|             
                             DAY ON TEST   | 0| 6| 3| 6| 4| 8| 1| 5| 4| 3| 8| 8| 8| 9| 3| 4| 7| 1| 8| 5| 6| 5| 8| 8| 8|             
                                           | 2| 8| 4| 7| 3| 8| 9| 5| 7| 4| 7| 1| 6| 0| 8| 6| 2| 6| 7| 1| 3| 2| 0| 4| 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|             
   FISCHER 344 RATS 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|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS - cont                   |                                                                          |             
                                           |                                                                          |             
      Leukemia Mononuclear                 |                            X              X  X              X           X|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  60                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 4| 6| 3| 6| 6| 6| 5| 6| 6| 5| 5| 7| 6| 6| 5| 6| 5| 3| 5| 6| 3| 6| 5| 5|            |
                             DAY ON TEST   | 6| 8| 6| 9| 7| 7| 6| 9| 2| 6| 0| 9| 0| 2| 4| 9| 4| 0| 7| 9| 9| 8| 9| 9| 3|            |
                                           | 9| 3| 1| 3| 9| 2| 3| 6| 6| 5| 7| 0| 9| 7| 1| 7| 5| 0| 7| 1| 6| 3| 6| 4| 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      |
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |                X                                                         |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |          X     X                                                         |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | A  A  +  A  +  +  +  +  A  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +|  39        |
      Leukemia Mononuclear                 |                X                                                         |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          3 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | A  A  A  A  +  +  A  +  A  +  A  +  +  +  A  +  +  A  +  +  +  A  +  +  +|  34        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | A  A  +  A  +  +  +  +  +  +  A  +  +  A  +  +  +  A  +  +  +  A  +  +  +|  37        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |          X     X                                               X     X   |          9 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                  +                                       |   3        |
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                      +                                                   |   1        |
      Pharyngeal, Squamous Cell Papilloma  |                      X                                                   |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          4 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          4 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          4 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X     X                                                     X   |          6 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          3 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Leukemia Mononuclear                 |          X                                                               |          3 |
      Pheochromocytoma Malignant           |                               X                                          |          2 |
      Pheochromocytoma Benign              |                                                 X           X     X      |          9 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  61                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 4| 6| 3| 6| 6| 6| 5| 6| 6| 5| 5| 7| 6| 6| 5| 6| 5| 3| 5| 6| 3| 6| 5| 5|            |
                             DAY ON TEST   | 6| 8| 6| 9| 7| 7| 6| 9| 2| 6| 0| 9| 0| 2| 4| 9| 4| 0| 7| 9| 9| 8| 9| 9| 3|            |
                                           | 9| 3| 1| 3| 9| 2| 3| 6| 6| 5| 7| 0| 9| 7| 1| 7| 5| 0| 7| 1| 6| 3| 6| 4| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Bilateral, Pheochromocytoma Benign   |             X                                                            |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                 X                        |          4 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  45        |
      Leukemia Mononuclear                 |          X                                                               |          3 |
      Pars Distalis, Adenoma               |                   X     X  X     X  X     X  X        X  X               |         18 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          3 |
      C-Cell, Adenoma                      |                            X        X                                    |          2 |
      Follicular Cell, Carcinoma           |       X                                                                  |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |             X                                                            |          2 |
      Leukemia Mononuclear                 |          X                                                               |          2 |
      Bilateral, Adenoma                   |                                                    X                     |          2 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          2 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          2 |
      Bilateral, Interstitial Cell, Adenoma| X     X     X  X  X  X  X     X  X  X  X  X  X  X  X     X  X     X  X  X|         40 |
      Interstitial Cell, Adenoma           |    X                                                                     |          4 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X     X                                               X         |          7 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +              +     +                    +                 +        +   |  14        |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          3 |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          1 |
      Renal, Leukemia Mononuclear          |                X                                                     X   |          6 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  62                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 4| 6| 3| 6| 6| 6| 5| 6| 6| 5| 5| 7| 6| 6| 5| 6| 5| 3| 5| 6| 3| 6| 5| 5|            |
                             DAY ON TEST   | 6| 8| 6| 9| 7| 7| 6| 9| 2| 6| 0| 9| 0| 2| 4| 9| 4| 0| 7| 9| 9| 8| 9| 9| 3|            |
                                           | 9| 3| 1| 3| 9| 2| 3| 6| 6| 5| 7| 0| 9| 7| 1| 7| 5| 0| 7| 1| 6| 3| 6| 4| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  M  M  +  +  M  M  M  M  +  +  M  +  +  M  +  M  +  +  M  +  +  +  +  +|  28        |
      Leukemia Mononuclear                 |          X                                                               |          4 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X     X                                                         |          7 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Leukemia Mononuclear                 |          X     X                                                         |          6 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X     X                                               X     X   |          9 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|  44        |
      Leukemia Mononuclear                 |          X                                                               |          4 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basal Cell Carcinoma                 |                                                                          |          1 |
      Keratoacanthoma                      |                X                                                         |          2 |
      Leukemia Mononuclear                 |                                                                          |          4 |
      Subcutaneous Tissue, Lipoma          |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                     +                                    |   1        |
      Sarcoma                              |                                     X                                    |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Glioma Malignant                     |                                                    X                     |          1 |
      Leukemia Mononuclear                 |          X                                                               |          1 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | M  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  M  M  M  +  +  +  M  +|  35        |
      Leukemia Mononuclear                 |          X                                                               |          2 |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Adenoma         |             X                                                            |          1 |
      Leukemia Mononuclear                 |          X     X                                                     X   |          7 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X                                                               |          3 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  63                                                               
NTP Experiment-Test: 05210-03                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                            ETHYLBENZENE                                       Date: 03/17/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 19:55:34  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 4| 6| 3| 6| 6| 6| 5| 6| 6| 5| 5| 7| 6| 6| 5| 6| 5| 3| 5| 6| 3| 6| 5| 5|            |
                             DAY ON TEST   | 6| 8| 6| 9| 7| 7| 6| 9| 2| 6| 0| 9| 0| 2| 4| 9| 4| 0| 7| 9| 9| 8| 9| 9| 3|            |
                                           | 9| 3| 1| 3| 9| 2| 3| 6| 6| 5| 7| 0| 9| 7| 1| 7| 5| 0| 7| 1| 6| 3| 6| 4| 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      |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                     +                                    |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X     X                                                     X   |          6 |
      Renal Tubule, Adenoma                |                   X                                                      |          4 |
      Renal Tubule, Carcinoma              |                                              X                           |          3 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |          X                                                     X         |          2 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |          X     X                                               X     X   |          9 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  64                                                               
                                  ------------------------------------------------------------                                      
                                  ----------              END OF REPORT             ----------                                      
                                  ------------------------------------------------------------