https://ntp.niehs.nih.gov/go/4404

TDMS Study 88034-04 Pathology Tables

                                     INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
                                                               OZONE
NTP Experiment-Test: 88034-04                                                                                     Report: PEIRPT03
Study Type: CHRONIC                                                                                               Date: 05/08/95
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29
       Facility:  Battelle Northwest
       Chemical CAS #:  10028-15-6
       Lock Date:  02/17/93
       Cage Range:  All
       Reasons For Removal:    All
       Removal Date Range:     All
       Treatment Groups:       Include All
a  Number of animals examined microscopically at site and number of animals with lesion
                                                             Page   1
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                15           10            9            9                                     
    Natural Death                                      6            3            6            1                                     
    Accidently Killed                                                            2                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                29           37           33           40                                     
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Gallbladder                                        (50)         (47)         (46)         (50)                                   
      Inflammation, Chronic Active                                               1 (2%)                                             
   Intestine Small, Duodenum                          (47)         (48)         (45)         (49)                                   
      Inflammation, Acute                                                                     1 (2%)                                
      Necrosis                                                                                1 (2%)                                
   Intestine Small, Jejunum                           (50)         (47)         (46)         (49)                                   
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Inflammation, Chronic Active                     1 (2%)                                                                       
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)                    1 (2%)       1 (2%)                                
      Basophilic Focus                                 1 (2%)       2 (4%)       2 (4%)                                             
      Clear Cell Focus                                 1 (2%)       1 (2%)       2 (4%)                                             
      Cyst                                                                       1 (2%)                                             
      Degeneration, Fatty                              1 (2%)                    1 (2%)                                             
      Eosinophilic Focus                               3 (6%)       3 (6%)       5 (10%)      4 (8%)                                
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       1 (2%)                                             
      Hepatodiaphragmatic Nodule                                                              1 (2%)                                
      Necrosis                                         1 (2%)       2 (4%)                    1 (2%)                                
      Centrilobular, Necrosis                                       1 (2%)                                                          
   Mesentery                                          (11)         (4)          (4)          (1)                                    
      Artery, Inflammation, Chronic Active             1 (9%)                                                                       
      Fat, Inflammation, Chronic                                    1 (25%)                                                         
      Fat, Necrosis                                    7 (64%)      3 (75%)      3 (75%)                                            
   Pancreas                                           (49)         (50)         (48)         (50)                                   
      Atrophy                                          1 (2%)       2 (4%)                    1 (2%)                                
      Basophilic Focus                                                                        1 (2%)                                
      Cyst                                                                       1 (2%)                                             
      Hypertrophy                                      1 (2%)                                 1 (2%)                                
      Lipomatosis                                                                             1 (2%)                                
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
   Salivary Glands                                    (50)         (49)         (49)         (50)                                   
      Degeneration, Fatty                                                        1 (2%)                                             
   Stomach, Forestomach                               (50)         (50)         (48)         (50)                                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT                                                                                                            
      Diverticulum                                                  1 (2%)                                                          
      Hyperplasia, Squamous                                         1 (2%)                    3 (6%)                                
      Inflammation, Acute                                           1 (2%)                    5 (10%)                               
      Mineralization                                                             1 (2%)                                             
      Necrosis                                         1 (2%)                                                                       
   Stomach, Glandular                                 (50)         (50)         (48)         (50)                                   
      Mineralization                                   2 (4%)       8 (16%)      6 (13%)      3 (6%)                                
      Necrosis                                                      1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                   6 (12%)      8 (16%)      5 (10%)      5 (10%)                               
      Mineralization                                   1 (2%)                                                                       
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
      Atrium, Thrombosis                               1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Cortex                                     (50)         (50)         (49)         (50)                                   
      Hematopoietic Cell Proliferation                                           1 (2%)                                             
      Hyperplasia                                      1 (2%)       4 (8%)       7 (14%)      3 (6%)                                
      Hypertrophy                                                   1 (2%)                    4 (8%)                                
      Vacuolization Cytoplasmic                        1 (2%)                    1 (2%)                                             
   Adrenal Medulla                                    (50)         (50)         (49)         (50)                                   
      Hyperplasia                                      1 (2%)       1 (2%)       2 (4%)       2 (4%)                                
   Islets, Pancreatic                                 (49)         (50)         (48)         (50)                                   
      Hyperplasia                                                                1 (2%)       1 (2%)                                
   Pituitary Gland                                    (50)         (50)         (47)         (49)                                   
      Cyst                                                          1 (2%)                                                          
      Pars Distalis, Hyperplasia                      11 (22%)     14 (28%)     20 (43%)     17 (35%)                               
      Pars Intermedia, Hyperplasia                     1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
   Thyroid Gland                                      (50)         (50)         (49)         (50)                                   
      Follicular Cell, Hyperplasia                     8 (16%)     19 (38%)     21 (43%)     25 (50%)                               
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Ovary                                              (50)         (50)         (48)         (50)                                   
      Angiectasis                                      2 (4%)                    2 (4%)                                             
      Cyst                                            11 (22%)     12 (24%)     13 (27%)     11 (22%)                               
      Hyperplasia, Tubular                                                       1 (2%)                                             
      Inflammation, Suppurative                                                               1 (2%)                                
      Thrombosis                                                    1 (2%)       1 (2%)                                             
   Uterus                                             (50)         (50)         (49)         (50)                                   
      Angiectasis                                      1 (2%)       2 (4%)       1 (2%)       2 (4%)                                
      Decidual Reaction                                1 (2%)                                                                       
      Hydrometra                                       4 (8%)       8 (16%)      3 (6%)       3 (6%)                                
      Inflammation, Suppurative                                                  1 (2%)       1 (2%)                                
      Necrosis                                                                   1 (2%)                                             
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (50)         (50)         (49)         (50)                                   
      Myelofibrosis                                    1 (2%)                                                                       
   Lymph Node                                         (9)          (6)          (3)          (4)                                    
      Iliac, Angiectasis                               1 (11%)                                                                      
      Iliac, Hematopoietic Cell Proliferation          1 (11%)                                                                      
      Iliac, Hemorrhage                                1 (11%)                                                                      
      Iliac, Infiltration Cellular, Plasma Cell                                  1 (33%)                                            
      Iliac, Infiltration Cellular, Histiocyte         1 (11%)                                                                      
      Lumbar, Infiltration Cellular, Histiocyte        1 (11%)                                                                      
      Renal, Hematopoietic Cell Proliferation          1 (11%)                                                                      
   Lymph Node, Bronchial                              (48)         (39)         (40)         (42)                                   
      Infiltration Cellular, Plasma Cell                                         1 (3%)                                             
   Lymph Node, Mandibular                             (47)         (39)         (43)         (46)                                   
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Infiltration Cellular, Histiocyte                1 (2%)                                                                       
   Lymph Node, Mesenteric                             (49)         (49)         (46)         (47)                                   
      Angiectasis                                      1 (2%)       1 (2%)                    1 (2%)                                
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Hemorrhage                                       2 (4%)                                 1 (2%)                                
      Inflammation, Chronic Active                     2 (4%)                                                                       
   Lymph Node, Mediastinal                            (41)         (42)         (39)         (35)                                   
      Infiltration Cellular, Plasma Cell                            1 (2%)                                                          
   Spleen                                             (49)         (50)         (48)         (50)                                   
      Hematopoietic Cell Proliferation                11 (22%)      6 (12%)     10 (21%)      3 (6%)                                
      Hyperplasia, Lymphoid                            2 (4%)       2 (4%)                    2 (4%)                                
      Hyperplasia, Mast Cell                           1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Mammary Gland                                      (50)         (50)         (48)         (49)                                   
      Hyperplasia                                                                             1 (2%)                                
   Skin                                               (50)         (50)         (49)         (50)                                   
      Prepuce, Inflammation, Chronic Active            1 (2%)       1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (50)         (49)         (50)                                   
      Necrosis                                                      1 (2%)                                                          
      Meninges, Inflammation, Chronic                  1 (2%)       1 (2%)       1 (2%)                                             
   Spinal Cord                                                                  (1)                                                 
      Inflammation, Chronic                                                      1 (100%)                                           
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Larynx                                             (50)         (50)         (49)         (50)                                   
      Inflammation, Chronic Active                     2 (4%)                                 1 (2%)                                
      Epiglottis, Hyperplasia                                                                 7 (14%)                               
      Epiglottis, Metaplasia, Squamous                                                        4 (8%)                                
   Lung                                               (50)         (50)         (49)         (50)                                   
      Congestion, Chronic                              1 (2%)       1 (2%)                                                          
      Thrombosis                                       1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 2 (4%)       1 (2%)       1 (2%)       2 (4%)                                
      Alveolar Epithelium, Metaplasia                                           43 (88%)     49 (98%)                               
      Alveolus, Infiltration Cellular, Histiocyte                               11 (22%)     42 (84%)                               
      Bronchiole, Hyperplasia                                                                 2 (4%)                                
      Bronchiole, Necrosis                                                                    1 (2%)                                
   Nose                                               (50)         (50)         (48)         (50)                                   
      Glands, Hyperplasia                                                                     1 (2%)                                
      Lateral Wall, Degeneration, Hyaline              5 (10%)     18 (36%)     48 (100%)    50 (100%)                              
      Lateral Wall, Fibrosis                                        3 (6%)      46 (96%)     50 (100%)                              
      Lateral Wall, Hyperplasia                                                 42 (88%)     50 (100%)                              
      Lateral Wall, Inflammation, Suppurative                       5 (10%)     46 (96%)     50 (100%)                              
      Lateral Wall, Metaplasia, Squamous               1 (2%)       1 (2%)      11 (23%)     36 (72%)                               
      Olfactory Epithelium, Atrophy                    4 (8%)       1 (2%)      14 (29%)     41 (82%)                               
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                                                       (2)                                    
      Inflammation, Chronic Active                                                            1 (50%)                               
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (50)         (50)         (49)         (50)                                   
      Amyloid Deposition                               1 (2%)                                                                       
      Infarct                                          1 (2%)                    1 (2%)       1 (2%)                                
      Nephropathy                                     25 (50%)     33 (66%)     29 (59%)     26 (52%)                               
      Renal Tubule, Necrosis                                        1 (2%)                                                          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                16           10           19           20                                     
    Natural Death                                      4            6            6            3                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                29           34           25           27                                     
    Natural Death                                      1                                                                            
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Gallbladder                                        (46)         (46)         (48)         (48)                                   
      Degeneration, Hyaline                                         1 (2%)                                                          
   Intestine Small, Duodenum                          (49)         (47)         (48)         (48)                                   
      Necrosis                                                                   1 (2%)                                             
   Intestine Small, Ileum                             (49)         (48)         (49)         (50)                                   
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Peyer's Patch, Infiltration Cellular, Plasma                                                                                  
          Cell                                         1 (2%)                                                                       
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                                                             1 (2%)                                
      Basophilic Focus                                              2 (4%)                                                          
      Clear Cell Focus                                 4 (8%)       4 (8%)       2 (4%)       1 (2%)                                
      Cyst                                             1 (2%)                                                                       
      Degeneration, Fatty                                                        1 (2%)                                             
      Eosinophilic Focus                               1 (2%)       2 (4%)                    2 (4%)                                
      Fibrosis                                         1 (2%)                    1 (2%)                                             
      Hematopoietic Cell Proliferation                                           1 (2%)                                             
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Karyomegaly                                                   1 (2%)                                                          
      Mineralization                                                1 (2%)                                                          
      Necrosis                                         3 (6%)       1 (2%)       1 (2%)                                             
      Centrilobular, Necrosis                                       1 (2%)                    2 (4%)                                
   Mesentery                                          (4)          (5)          (1)          (3)                                    
      Inflammation, Chronic Active                                  1 (20%)                                                         
      Fat, Necrosis                                    3 (75%)      3 (60%)                   3 (100%)                              
   Pancreas                                           (49)         (50)         (50)         (50)                                   
      Atrophy                                          1 (2%)       1 (2%)                                                          
      Basophilic Focus                                              1 (2%)                                                          
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Angiectasis                                                   1 (2%)                                                          
      Hyperplasia, Squamous                            1 (2%)       1 (2%)                                                          
      Inflammation, Acute                              3 (6%)       1 (2%)                                                          
      Necrosis                                         1 (2%)                    1 (2%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT                                                                                                            
   Stomach, Glandular                                 (50)         (49)         (50)         (50)                                   
      Inflammation, Acute                                                        1 (2%)                                             
   Tooth                                              (1)          (1)          (1)          (1)                                    
      Developmental Malformation                                                              1 (100%)                              
      Inflammation, Chronic Active                     1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                   8 (16%)     18 (36%)     11 (22%)     17 (34%)                               
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Thrombosis                                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Atrophy                                                                    1 (2%)                                             
      Hyperplasia                                     14 (28%)      9 (18%)     12 (24%)     15 (30%)                               
      Hypertrophy                                     26 (52%)     31 (62%)     22 (44%)     22 (44%)                               
      Capsule, Hyperplasia                             3 (6%)                    1 (2%)       1 (2%)                                
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      2 (4%)       2 (4%)       2 (4%)       3 (6%)                                
   Pituitary Gland                                    (47)         (49)         (49)         (48)                                   
      Cyst                                             1 (2%)                    1 (2%)       1 (2%)                                
      Pars Distalis, Hyperplasia                       5 (11%)      2 (4%)       1 (2%)                                             
   Thyroid Gland                                      (49)         (50)         (50)         (50)                                   
      Inflammation, Chronic                                                                   2 (4%)                                
      Follicular Cell, Hyperplasia                     6 (12%)      8 (16%)     10 (20%)     17 (34%)                               
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm                                  1 (2%)       2 (4%)       1 (2%)                                             
   Penis                                                                        (2)          (1)                                    
      Inflammation, Acute                                                        1 (50%)      1 (100%)                              
   Preputial Gland                                    (50)         (50)         (50)         (50)                                   
      Cyst                                                                       1 (2%)                                             
      Hyperplasia                                      1 (2%)                                                                       
      Inflammation, Chronic Active                    12 (24%)      4 (8%)       6 (12%)      2 (4%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
GENITAL SYSTEM - CONT                                                                                                               
      Necrosis                                                                                1 (2%)                                
   Prostate                                           (49)         (50)         (47)         (49)                                   
      Inflammation, Suppurative                        1 (2%)                    2 (4%)       2 (4%)                                
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
   Seminal Vesicle                                    (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic Active                     1 (2%)       1 (2%)                    1 (2%)                                
   Testes                                             (50)         (50)         (50)         (50)                                   
      Atrophy                                          4 (8%)       2 (4%)       1 (2%)       4 (8%)                                
      Mineralization                                   1 (2%)                                 3 (6%)                                
      Interstitial Cell, Hyperplasia                                             1 (2%)                                             
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (49)         (50)         (50)         (50)                                   
      Atrophy                                          1 (2%)                                                                       
      Necrosis                                         1 (2%)                                                                       
   Lymph Node                                         (4)          (6)          (3)          (10)                                   
      Iliac, Infiltration Cellular, Plasma Cell        1 (25%)      1 (17%)      1 (33%)      7 (70%)                               
      Inguinal, Infiltration Cellular, Plasma Cell                  1 (17%)                                                         
      Renal, Infiltration Cellular, Plasma Cell        1 (25%)                                1 (10%)                               
   Lymph Node, Mesenteric                             (48)         (49)         (49)         (49)                                   
      Angiectasis                                      1 (2%)                                 1 (2%)                                
      Hemorrhage                                                                              2 (4%)                                
   Spleen                                             (49)         (50)         (49)         (50)                                   
      Angiectasis                                                                1 (2%)                                             
      Hematopoietic Cell Proliferation                 2 (4%)       3 (6%)       3 (6%)       6 (12%)                               
      Necrosis                                         1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Skin                                               (50)         (50)         (50)         (50)                                   
      Ulcer                                            1 (2%)                                                                       
      Prepuce, Inflammation, Chronic Active            8 (16%)      6 (12%)     12 (24%)     20 (40%)                               
      Subcutaneous Tissue, Fibrosis                                                           1 (2%)                                
      Subcutaneous Tissue, Inflammation,                                                                                            
          Granulomatous                                1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (50)         (50)         (50)                                   
      Hemorrhage                                       1 (2%)                                                                       
      Necrosis                                         1 (2%)                                                                       
      Meninges, Inflammation, Chronic                               1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Larynx                                             (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Chronic Active                     4 (8%)      13 (26%)      4 (8%)       9 (18%)                               
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
      Epiglottis, Hyperplasia                          1 (2%)                                 6 (12%)                               
      Epiglottis, Metaplasia, Squamous                                                        2 (4%)                                
   Lung                                               (50)         (50)         (50)         (50)                                   
      Fibrosis                                                                   1 (2%)                                             
      Hemorrhage                                       1 (2%)                    1 (2%)       1 (2%)                                
      Thrombosis                                       1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 4 (8%)       6 (12%)      2 (4%)       3 (6%)                                
      Alveolar Epithelium, Metaplasia                                           48 (96%)     50 (100%)                              
      Alveolus, Infiltration Cellular, Histiocyte                               18 (36%)     31 (62%)                               
      Bronchiole, Erosion                                                                     1 (2%)                                
      Bronchiole, Hyperplasia                                                                 1 (2%)                                
      Bronchiole, Necrosis                                                                    3 (6%)                                
      Bronchus, Erosion                                                                       1 (2%)                                
      Bronchus, Necrosis                                                                      1 (2%)                                
   Nose                                               (50)         (50)         (50)         (50)                                   
      Inflammation, Suppurative                        2 (4%)                                                                       
      Lateral Wall, Degeneration, Hyaline              2 (4%)       1 (2%)      49 (98%)     50 (100%)                              
      Lateral Wall, Fibrosis                                                    47 (94%)     49 (98%)                               
      Lateral Wall, Hyperplasia                                                 42 (84%)     50 (100%)                              
      Lateral Wall, Inflammation, Suppurative                       8 (16%)     42 (84%)     50 (100%)                              
      Lateral Wall, Metaplasia, Squamous                            3 (6%)       3 (6%)      36 (72%)                               
      Nasopharyngeal Duct, Inflammation, Chronic                                                                                    
          Active                                                    1 (2%)                                                          
      Olfactory Epithelium, Atrophy                    1 (2%)       3 (6%)       3 (6%)      11 (22%)                               
      Olfactory Epithelium, Metaplasia                 1 (2%)                                                                       
   Trachea                                            (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Polymorphonuclear                                   1 (2%)                                             
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 88034-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                               OZONE                                           Date: 05/08/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 20:38:29  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      0.12 PPM     0.5 PPM      1.0 PPM                                   
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                             (1)                                                              
      Cataract                                                      1 (100%)                                                        
   Harderian Gland                                    (1)          (8)          (6)          (4)                                    
      Hyperplasia                                                   1 (13%)                                                         
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Cyst                                             1 (2%)       1 (2%)       1 (2%)                                             
      Infarct                                          3 (6%)       1 (2%)       1 (2%)       6 (12%)                               
      Metaplasia, Osseous                                           1 (2%)                    4 (8%)                                
      Nephropathy                                     43 (86%)     40 (80%)     46 (92%)     37 (74%)                               
      Papilla, Inflammation, Suppurative               6 (12%)      3 (6%)       8 (16%)     14 (28%)                               
      Pelvis, Dilatation                               3 (6%)       4 (8%)       4 (8%)       4 (8%)                                
   Urethra                                                                                   (3)                                    
      Inflammation, Suppurative                                                               1 (33%)                               
      Bulbourethral Gland, Inflammation,                                                                                            
          Suppurative                                                                         2 (67%)                               
   Urinary Bladder                                    (50)         (50)         (50)         (49)                                   
      Inflammation, Chronic Active                     6 (12%)      3 (6%)       8 (16%)     13 (27%)                               
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
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