Share This:
https://ntp.niehs.nih.gov/go/2936

TDMS Study 05134-02 Pathology Tables


                                     INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
                                                     1,3 BUTADIENE (BUTADIENE)


NTP Experiment-Test: 05134-02                                                                                     Report: PEIRPT03
Study Type: CHRONIC                                                                                               Date: 09/17/94
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58




       Facility:  Battelle Northwest

       Chemical CAS #:  106-99-0

       Lock Date:  None

       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: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          70           70           70           70           70           90           
  Scheduled Sacrifice                                 20           20           20           20           20           10           
  Early Deaths                                                                                                                      
    Moribund                                          10           10           14           31           37           46           
    Dead                                               3            7           11            8           12           33           
    Accident                                                                     1                         1            1           
  Survivors                                                                                                                         
    Terminal Sacrifice                                37           33           24           11                                     
  Animals Examined Microscopically                    70           70           70           70           70           90           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (61)         (41)         (47)         (45)         (58)         (89)         
      Acanthosis                                       1 (2%)                                                                       
   Gallbladder                                        (66)         (44)         (41)         (43)         (49)         (64)         
      Hyperplasia                                      1 (2%)                                 3 (7%)                                
      Inflammation                                     1 (2%)                    1 (2%)       2 (5%)                    1 (2%)      
   Intestine Large, Cecum                             (68)         (46)         (46)         (47)         (57)         (78)         
      Hemorrhage                                                    1 (2%)                                                          
   Intestine Large, Colon                             (68)         (48)         (47)         (47)         (58)         (83)         
      Endothelium, Hyperplasia                                                   1 (2%)                                             
   Intestine Small, Ileum                             (68)         (46)         (43)         (47)         (55)         (75)         
      Inflammation, Chronic                                         1 (2%)                                                          
      Peyer's Patch, Hyperplasia                                                                           1 (2%)                   
   Intestine Small, Jejunum                           (67)         (45)         (44)         (47)         (54)         (70)         
      Hemorrhage                                                                                                        2 (3%)      
      Peyer's Patch, Hyperplasia                                                              1 (2%)                                
   Liver                                              (69)         (52)         (51)         (61)         (61)         (90)         
      Angiectasis                                                   5 (10%)      1 (2%)       3 (5%)       2 (3%)       1 (1%)      
      Basophilic Focus                                 1 (1%)       2 (4%)       1 (2%)       4 (7%)       2 (3%)       1 (1%)      
      Clear Cell Focus                                 2 (3%)       1 (2%)                    1 (2%)                                
      Degeneration, Fatty                              2 (3%)       2 (4%)       1 (2%)       8 (13%)      4 (7%)                   
      Eosinophilic Focus                               5 (7%)      12 (23%)     19 (37%)     11 (18%)      5 (8%)       2 (2%)      
      Hematopoietic Cell Proliferation                 3 (4%)       6 (12%)      1 (2%)      11 (18%)     14 (23%)     10 (11%)     
      Infarct                                                                    1 (2%)                                             
      Inflammation, Chronic                            1 (1%)       1 (2%)                                              1 (1%)      
      Inflammation, Focal, Granulomatous               1 (1%)       1 (2%)       1 (2%)                                             
      Mixed Cell Focus                                              1 (2%)                    1 (2%)       1 (2%)       1 (1%)      
      Necrosis                                         2 (3%)       2 (4%)       7 (14%)      5 (8%)      22 (36%)     19 (21%)     
      Pigmentation, Bile                                                                                   1 (2%)                   
      Thrombosis                                                                                           1 (2%)       1 (1%)      
      Biliary Tract, Cyst                              1 (1%)                                 1 (2%)       1 (2%)       2 (2%)      
      Biliary Tract, Hyperplasia                                                              1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Centrilobular, Degeneration, Fatty                                                      1 (2%)       1 (2%)       3 (3%)      
      Centrilobular, Necrosis                                                                 1 (2%)       4 (7%)       7 (8%)      
   Mesentery                                          (12)         (13)         (16)         (9)          (15)         (6)          
      Fat, Angiectasis                                 3 (25%)      3 (23%)      4 (25%)      3 (33%)      1 (7%)                   
      Fat, Ectopic Tissue                                           1 (8%)                                                          
      Fat, Hemorrhage                                  1 (8%)                    1 (6%)                    2 (13%)                  
      Fat, Inflammation, Chronic                       4 (33%)      3 (23%)      7 (44%)      2 (22%)      7 (47%)      1 (17%)     
      Fat, Necrosis                                    8 (67%)      6 (46%)      6 (38%)      3 (33%)      7 (47%)                  
   Pancreas                                           (69)         (49)         (47)         (48)         (59)         (88)         
      Acinus, Atrophy                                  3 (4%)       3 (6%)       5 (11%)                   2 (3%)       1 (1%)      
      Acinus, Focal Cellular Change                    3 (4%)       5 (10%)      3 (6%)       3 (6%)       1 (2%)                   
      Acinus, Hyperplasia                              1 (1%)                    1 (2%)                    1 (2%)                   
      Acinus, Infarct                                  1 (1%)                                                                       
      Acinus, Inflammation, Chronic                    2 (3%)                    3 (6%)                                             
      Duct, Cyst                                       2 (3%)                    2 (4%)                                 1 (1%)      
   Salivary Glands                                    (70)         (49)         (50)         (49)         (60)         (89)         
      Atrophy, Focal                                                                          1 (2%)                                
      Inflammation                                     3 (4%)                                 4 (8%)                                
      Inflammation, Chronic                                                      1 (2%)                                             
   Stomach, Forestomach                               (70)         (50)         (57)         (68)         (70)         (89)         
      Cyst Epithelial Inclusion                                     1 (2%)                                                          
      Mineralization                                                             1 (2%)                                             
      Ulcer                                            2 (3%)       2 (4%)       1 (2%)       3 (4%)       5 (7%)      14 (16%)     
      Epithelium, Hyperplasia                          4 (6%)       5 (10%)      4 (7%)       8 (12%)     18 (26%)     56 (63%)     
   Stomach, Glandular                                 (69)         (49)         (58)         (68)         (68)         (86)         
      Hemorrhage                                                    1 (2%)                                              2 (2%)      
      Inflammation, Suppurative                                     1 (2%)                                                          
      Mineralization                                                                          1 (1%)                                
      Pigmentation, Hemosiderin                        2 (3%)       2 (4%)       1 (2%)       2 (3%)       5 (7%)       4 (5%)      
      Ulcer                                            2 (3%)       1 (2%)       1 (2%)       2 (3%)       6 (9%)       2 (2%)      
      Epithelium, Hyperplasia                                                                                           1 (1%)      
   Tooth                                              (4)          (5)          (1)                                                 
      Developmental Malformation                       1 (25%)                                                                      
      Inflammation                                     3 (75%)      4 (80%)      1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (1)          (1)                       (1)                       (1)          
      Inflammation                                     1 (100%)     1 (100%)                                                        
      Mineralization                                                                          1 (100%)                              
   Heart                                              (70)         (50)         (50)         (59)         (70)         (90)         
      Cardiomyopathy                                   4 (6%)       2 (4%)       1 (2%)       4 (7%)                    2 (2%)      
      Infiltration Cellular, Mixed Cell                                                                    1 (1%)                   
      Mineralization                                                2 (4%)                    2 (3%)       2 (3%)      11 (12%)     
      Necrosis                                                                                2 (3%)       1 (1%)       3 (3%)      
      Atrium, Thrombosis                                                                                                2 (2%)      
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
CARDIOVASCULAR SYSTEM - CONT                                                                                                        
      Endothelium, Hyperplasia                                      2 (4%)       1 (2%)       4 (7%)       9 (13%)      9 (10%)     
      Pericardium, Inflammation, Chronic                                                      1 (2%)                                
      Pericardium, Fat, Necrosis                                                              1 (2%)                                
      Perivascular, Inflammation                       1 (1%)       1 (2%)       1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (70)         (49)         (48)         (49)         (60)         (88)         
      Cyst                                                                       1 (2%)       4 (8%)       1 (2%)                   
      Focal Cellular Change                                         3 (6%)                                                          
      Hematocyst                                                                                           1 (2%)                   
      Hematopoietic Cell Proliferation                 1 (1%)                    1 (2%)       4 (8%)       5 (8%)       2 (2%)      
      Hemorrhage                                                                                                        1 (1%)      
      Hyperplasia                                      3 (4%)                                 2 (4%)       2 (3%)       1 (1%)      
      Hypertrophy                                      1 (1%)       3 (6%)       1 (2%)       3 (6%)       3 (5%)                   
      Capsule, Hyperplasia                                          2 (4%)                                                          
   Adrenal Gland, Medulla                             (70)         (48)         (47)         (45)         (60)         (86)         
      Cyst                                                                                    1 (2%)                                
      Hematopoietic Cell Proliferation                                                                                  1 (1%)      
      Hyperplasia                                      3 (4%)       1 (2%)       1 (2%)       2 (4%)                                
   Islets, Pancreatic                                 (69)         (49)         (46)         (47)         (59)         (88)         
      Hyperplasia                                      2 (3%)                    2 (4%)                                             
   Parathyroid Gland                                  (57)         (40)         (33)         (39)         (47)         (77)         
      Cyst                                                          1 (3%)                                              1 (1%)      
   Pituitary Gland                                    (70)         (49)         (48)         (47)         (58)         (80)         
      Pars Distalis, Angiectasis                       1 (1%)       2 (4%)       3 (6%)       1 (2%)                                
      Pars Distalis, Cyst                                           1 (2%)       1 (2%)                    1 (2%)       2 (3%)      
      Pars Distalis, Hemorrhage                                     1 (2%)                                                          
      Pars Distalis, Hyperplasia                      13 (19%)     19 (39%)     10 (21%)      9 (19%)                               
      Pars Intermedia, Hyperplasia                                  2 (4%)       1 (2%)                                             
   Thyroid Gland                                      (69)         (49)         (49)         (49)         (59)         (88)         
      Cyst                                             1 (1%)       6 (12%)      1 (2%)       4 (8%)       1 (2%)                   
      Inflammation                                     2 (3%)                    2 (4%)       2 (4%)                                
      C-Cell, Hyperplasia                                                                     1 (2%)                                
      Follicular Cell, Hyperplasia                    11 (16%)     10 (20%)     13 (27%)      6 (12%)      2 (3%)       1 (1%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (69)         (59)         (58)         (70)         (70)         (89)         
      Angiectasis                                      5 (7%)       7 (12%)      3 (5%)      13 (19%)     16 (23%)     17 (19%)     
      Atrophy                                          4 (6%)      19 (32%)     33 (57%)     51 (73%)     59 (84%)     79 (89%)     
      Cyst                                            16 (23%)     29 (49%)     21 (36%)     19 (27%)     12 (17%)     13 (15%)     
      Metaplasia, Osseous                                           1 (2%)                                                          
      Mineralization                                                1 (2%)                                                          
      Corpus Luteum, Hyperplasia                                    1 (2%)                                                          
      Germinal Epithelium, Hyperplasia                 2 (3%)       3 (5%)       8 (14%)     15 (21%)     17 (24%)     20 (22%)     
      Granulosa Cell, Hyperplasia                      1 (1%)                    2 (3%)       3 (4%)       5 (7%)       3 (3%)      
   Uterus                                             (70)         (50)         (60)         (69)         (70)         (88)         
      Angiectasis                                      3 (4%)       8 (16%)     10 (17%)      6 (9%)       2 (3%)                   
      Atrophy                                          1 (1%)                    1 (2%)       1 (1%)      11 (16%)     49 (56%)     
      Cyst                                             1 (1%)                                 1 (1%)                    1 (1%)      
      Dilatation                                       2 (3%)       2 (4%)                                                          
      Hemorrhage                                                    1 (2%)       2 (3%)       1 (1%)                                
      Hyperplasia, Cystic                             63 (90%)     48 (96%)     50 (83%)     58 (84%)     30 (43%)                  
      Hyperplasia, Histiocytic                                                                                          1 (1%)      
      Inflammation                                     1 (1%)       1 (2%)                                                          
      Thrombosis                                                                              1 (1%)       1 (1%)                   
      Arteriole, Hypertrophy                           1 (1%)       1 (2%)                                                          
      Cervix, Cyst                                                  1 (2%)                                                          
      Muscularis, Hyperplasia                                       1 (2%)                                 1 (1%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (70)         (49)         (48)         (59)         (70)         (89)         
      Angiectasis                                                                             1 (2%)                                
      Atrophy                                                                                                          12 (13%)     
      Fibrosis                                                                   1 (2%)       1 (2%)       1 (1%)                   
      Hyperplasia                                      4 (6%)       5 (10%)      9 (19%)     18 (31%)     18 (26%)     20 (22%)     
      Necrosis                                                                                                          2 (2%)      
   Lymph Node                                         (70)         (50)         (50)         (60)         (69)         (89)         
      Iliac, Hyperplasia                                                         1 (2%)                                             
      Pancreatic, Hyperplasia                                       1 (2%)                                                          
      Renal, Hyperplasia                                            1 (2%)                                 1 (1%)                   
   Lymph Node, Bronchial                              (58)         (42)         (42)         (41)         (46)         (62)         
      Congestion                                                    1 (2%)                                 1 (2%)       2 (3%)      
      Hematopoietic Cell Proliferation                 1 (2%)                                 1 (2%)       2 (4%)                   
      Hyperplasia                                      9 (16%)     10 (24%)      6 (14%)      1 (2%)       1 (2%)                   
      Inflammation                                                                            1 (2%)                                
   Lymph Node, Mandibular                             (53)         (42)         (46)         (49)         (54)         (64)         
      Congestion                                       1 (2%)                                                                       
      Hematopoietic Cell Proliferation                 2 (4%)                                 3 (6%)       2 (4%)                   
      Hyperplasia                                      8 (15%)      5 (12%)      3 (7%)       5 (10%)      2 (4%)                   
      Hyperplasia, Histiocytic                                                                                          3 (5%)      
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Hyperplasia, Plasma Cell                                                                                          1 (2%)      
      Necrosis                                                                                                          1 (2%)      
   Lymph Node, Mediastinal                            (39)         (29)         (33)         (44)         (51)         (74)         
      Angiectasis                                                   1 (3%)                                                          
      Congestion                                                    1 (3%)                                 1 (2%)       4 (5%)      
      Hematopoietic Cell Proliferation                 2 (5%)                                 3 (7%)       2 (4%)       1 (1%)      
      Hyperplasia                                      6 (15%)      1 (3%)       2 (6%)       3 (7%)       3 (6%)       1 (1%)      
   Lymph Node, Mesenteric                             (69)         (46)         (48)         (58)         (66)         (81)         
      Angiectasis                                      3 (4%)       2 (4%)       3 (6%)       4 (7%)       1 (2%)                   
      Congestion                                                    1 (2%)       1 (2%)                                 1 (1%)      
      Hematopoietic Cell Proliferation                 2 (3%)       1 (2%)       2 (4%)       3 (5%)       2 (3%)                   
      Hemorrhage                                                    1 (2%)                                              1 (1%)      
      Hyperplasia                                      9 (13%)     17 (37%)      7 (15%)      6 (10%)      3 (5%)       1 (1%)      
      Hyperplasia, Histiocytic                         1 (1%)                                                           1 (1%)      
      Inflammation                                                                                                      1 (1%)      
      Inflammation, Granulomatous                                                                          2 (3%)                   
      Necrosis                                                                                                          1 (1%)      
   Spleen                                             (69)         (49)         (48)         (58)         (70)         (88)         
      Angiectasis                                                                1 (2%)                    1 (1%)                   
      Depletion Lymphoid                                                                                                1 (1%)      
      Hematopoietic Cell Proliferation                27 (39%)     25 (51%)     24 (50%)     29 (50%)     28 (40%)     28 (32%)     
      Hemorrhage                                                                 1 (2%)                                             
      Hyperplasia, Histiocytic                         1 (1%)                                                           1 (1%)      
      Hyperplasia, Lymphoid                            2 (3%)       3 (6%)       2 (4%)       1 (2%)                                
      Inflammation, Focal, Granulomatous                            1 (2%)                                                          
      Necrosis                                                                                             1 (1%)                   
      Capsule, Inflammation, Chronic                                             2 (4%)                    1 (1%)                   
   Thymus                                             (66)         (46)         (45)         (51)         (59)         (81)         
      Angiectasis                                                   2 (4%)       1 (2%)                                             
      Hyperplasia, Lymphoid                            8 (12%)     14 (30%)      3 (7%)       2 (4%)       1 (2%)                   
      Infiltration Cellular, Mixed Cell                                                       1 (2%)       1 (2%)                   
      Necrosis                                         1 (2%)       6 (13%)      6 (13%)     16 (31%)     22 (37%)     25 (31%)     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (69)         (46)         (49)         (61)         (58)         (87)         
      Galactocele                                      1 (1%)                    1 (2%)       1 (2%)       1 (2%)                   
      Hyperplasia                                      2 (3%)                    2 (4%)       5 (8%)       9 (16%)      2 (2%)      
   Skin                                               (70)         (50)         (50)         (53)         (60)         (89)         
      Acanthosis                                                    1 (2%)                                                          
      Cyst Epithelial Inclusion                                                  1 (2%)                                             
      Inflammation, Chronic                            1 (1%)       1 (2%)                                 2 (3%)                   
      Necrosis                                                                   1 (2%)                    1 (2%)                   
      Hair Follicle, Atrophy                                                     2 (4%)       3 (6%)                                
      Subcutaneous Tissue, Edema                                    1 (2%)                                                          
      Subcutaneous Tissue, Hemorrhage                                            2 (4%)       1 (2%)       1 (2%)       1 (1%)      
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - CONT                                                                                                         
      Subcutaneous Tissue, Inflammation,                                                                                            
          Granulomatous                                                                                    1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (70)         (50)         (50)         (50)         (60)         (90)         
      Developmental Malformation                       1 (1%)                                                                       
      Fibrous Osteodystrophy                          38 (54%)     36 (72%)     29 (58%)     22 (44%)     12 (20%)                  
      Osteopetrosis                                                 1 (2%)                                 1 (2%)                   
      Proliferation Connective Tissue                  1 (1%)                                                                       
      Periosteum, Hemorrhage                                                                                            1 (1%)      
   Skeletal Muscle                                    (1)                       (1)          (1)          (2)          (2)          
      Hemorrhage                                                                                           1 (50%)      1 (50%)     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (70)         (50)         (50)         (50)         (60)         (90)         
      Compression                                      1 (1%)                    1 (2%)                                             
      Hemorrhage                                                                 3 (6%)       3 (6%)       2 (3%)       6 (7%)      
      Infiltration Cellular, Mixed Cell                                                                                 1 (1%)      
      Mineralization                                  24 (34%)     24 (48%)     17 (34%)     14 (28%)      7 (12%)     12 (13%)     
      Necrosis                                                                                             1 (2%)                   
      Thrombosis                                                                                                        1 (1%)      
      Perivascular, Infiltration Cellular,                                                                                          
          Lymphocyte                                                3 (6%)                                                          
      Ventricle, Cyst Epithelial Inclusion                                                                              1 (1%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (70)         (50)         (49)         (47)         (59)         (82)         
      Inflammation                                                                            1 (2%)                    1 (1%)      
      Inflammation, Suppurative                        1 (1%)       1 (2%)                                                          
   Lung                                               (70)         (60)         (60)         (70)         (70)         (88)         
      Hemorrhage                                       3 (4%)       4 (7%)       6 (10%)      5 (7%)      10 (14%)     13 (15%)     
      Hyperplasia, Lymphoid                            1 (1%)       1 (2%)                                                          
      Infiltration Cellular, Mixed Cell                                          1 (2%)                    2 (3%)       3 (3%)      
      Inflammation, Chronic, Diffuse                                                                       1 (1%)                   
      Inflammation, Chronic, Focal                     3 (4%)       2 (3%)                    1 (1%)       2 (3%)                   
      Inflammation, Focal, Granulomatous                                                      1 (1%)                                
      Inflammation, Suppurative                                     1 (2%)                    1 (1%)       1 (1%)                   
      Thrombosis                                                                 1 (2%)                                 1 (1%)      
      Alveolar Epithelium, Hyperplasia                 5 (7%)       5 (8%)       4 (7%)      11 (16%)     17 (24%)     13 (15%)     
      Alveolus, Infiltration Cellular, Histiocyte      1 (1%)       3 (5%)       7 (12%)      7 (10%)     10 (14%)      3 (3%)      
      Alveolus, Pigmentation, Hemosiderin              1 (1%)                    2 (3%)       2 (3%)       1 (1%)                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Fat, Mediastinum, Inflammation, Chronic          1 (1%)                                                                       
      Fat, Mediastinum, Necrosis                       1 (1%)                    1 (2%)                                             
      Mediastinum, Hyperplasia, Lymphoid               1 (1%)                                                                       
      Peribronchiolar, Inflammation,                                                                                                
          Pyogranulomatous                                                                                              1 (1%)      
   Nose                                               (70)         (49)         (48)         (50)         (60)         (89)         
      Inflammation, Suppurative                       19 (27%)     12 (24%)     13 (27%)     11 (22%)      7 (12%)      1 (1%)      
      Nasolacrimal Duct, Inflammation, Suppurative     2 (3%)       1 (2%)       6 (13%)      4 (8%)       1 (2%)                   
      Olfactory Epithelium, Atrophy                    2 (3%)                                                           7 (8%)      
      Olfactory Epithelium, Inflammation, Chronic                                                                       1 (1%)      
      Respiratory Epithelium, Hyperplasia                                                                  1 (2%)                   
      Respiratory Epithelium, Metaplasia, Squamous     1 (1%)                                              2 (3%)                   
   Trachea                                            (69)         (50)         (48)         (49)         (60)         (83)         
      Inflammation, Suppurative                       13 (19%)     17 (34%)     14 (29%)     10 (20%)      8 (13%)                  
      Metaplasia, Squamous                                                                                 1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (3)                       (2)          (2)          (3)          (3)          
      Degeneration                                     2 (67%)                   1 (50%)                                            
      Cornea, Hyperplasia                                                                     1 (50%)      1 (33%)                  
      Cornea, Inflammation, Chronic                                              1 (50%)      1 (50%)      2 (67%)                  
      Lens, Degeneration                                                                      2 (100%)                              
   Harderian Gland                                    (64)         (50)         (49)         (59)         (60)         (73)         
      Hyperplasia                                      1 (2%)       5 (10%)      9 (18%)      4 (7%)       5 (8%)       7 (10%)     
      Inflammation, Chronic                            1 (2%)                    1 (2%)                                 1 (1%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (69)         (49)         (48)         (50)         (60)         (90)         
      Amyloid Deposition                                                                                   1 (2%)                   
      Glomerulosclerosis                                                                                                1 (1%)      
      Hematopoietic Cell Proliferation                              1 (2%)                                 2 (3%)                   
      Hydronephrosis                                   2 (3%)                                 2 (4%)       2 (3%)                   
      Infarct                                                                                              1 (2%)                   
      Infiltration Cellular, Lymphocyte                1 (1%)       1 (2%)                                                          
      Inflammation, Suppurative                        1 (1%)                                              1 (2%)                   
      Metaplasia, Osseous                              1 (1%)       1 (2%)       2 (4%)                    2 (3%)       1 (1%)      
      Nephropathy                                     11 (16%)      3 (6%)       3 (6%)       6 (12%)      1 (2%)                   
      Pigmentation, Hemosiderin                                                               2 (4%)                                
      Thrombosis                                                                                                        1 (1%)      
      Capsule, Inflammation, Chronic                                                                       1 (2%)                   
      Medulla, Congestion                                                                                  1 (2%)                   
      Renal Tubule, Degeneration                                                              1 (2%)                                
      Renal Tubule, Hyperplasia                                                               1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      625 PPM         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Renal Tubule, Mineralization                                                            1 (2%)                                
   Urinary Bladder                                    (67)         (46)         (48)         (46)         (59)         (85)         
      Hemorrhage                                                                                                        3 (4%)      
      Hyperplasia, Histiocytic                                                                                          1 (1%)      
      Inflammation                                     2 (3%)       1 (2%)                                                          
      Transitional Epithelium, Hyperplasia             1 (1%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      200 PPM         
                                                                                                                    SE40            
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          70           70           70           70           70           50           
  Scheduled Sacrifice                                 20           20           20           20           20                        
  Early Deaths                                                                                                                      
    Dead                                               6            5           11           12           23           12           
    Moribund                                           9            6           15           15           23           29           
  Survivors                                                                                                                         
    Terminal Sacrifice                                35           39           24           22            3            9           
    Dead                                                                                                   1                        
  Missing                                                                                     1                                     
  Animals Examined Microscopically                    70           70           70           70           70           50           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (64)         (47)         (39)         (36)         (42)         (40)         
      Hyperplasia                                                   2 (4%)                                 1 (2%)       1 (3%)      
      Inflammation                                                  1 (2%)                                                          
   Intestine Large, Cecum                             (70)         (46)         (42)         (44)         (50)         (42)         
      Angiectasis                                                                                          1 (2%)                   
      Inflammation                                     1 (1%)                                                                       
   Intestine Large, Rectum                            (70)         (47)         (46)         (48)         (55)         (44)         
      Hemorrhage                                                                              1 (2%)                                
   Intestine Small                                    (69)         (48)         (44)         (47)         (49)         (44)         
      Epithelium, Hyperplasia                                                    1 (2%)                                             
   Intestine Small, Duodenum                          (67)         (46)         (42)         (44)         (47)         (42)         
      Angiectasis                                                   1 (2%)                                                          
      Hemorrhage                                                    1 (2%)                                                          
      Inflammation, Chronic                                                      1 (2%)                                             
      Pigmentation, Hemosiderin                                                  1 (2%)                                             
      Ulcer                                            1 (1%)                                                                       
      Peyer's Patch, Hyperplasia                       1 (1%)                                 1 (2%)                                
   Intestine Small, Ileum                             (68)         (48)         (43)         (46)         (47)         (44)         
      Peyer's Patch, Hyperplasia                                    2 (4%)                    2 (4%)                                
   Intestine Small, Jejunum                           (68)         (46)         (43)         (44)         (43)         (43)         
      Cyst                                                                       1 (2%)                                             
      Inflammation, Chronic                                                      1 (2%)                                             
      Pigmentation, Hemosiderin                                                  1 (2%)                                             
      Peyer's Patch, Hyperplasia                                    2 (4%)                    3 (7%)       1 (2%)       1 (2%)      
      Peyer's Patch, Inflammation, Granulomatous       1 (1%)                                                                       
   Liver                                              (70)         (61)         (61)         (60)         (68)         (49)         
      Angiectasis                                                   4 (7%)                    3 (5%)                    1 (2%)      
      Basophilic Focus                                 3 (4%)       3 (5%)       3 (5%)       5 (8%)       1 (1%)       3 (6%)      
      Clear Cell Focus                                 2 (3%)       1 (2%)       1 (2%)                                 1 (2%)      
      Degeneration, Fatty                                           4 (7%)       3 (5%)                    1 (1%)                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      200 PPM         
                                                                                                                    SE40            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Developmental Malformation                                                              1 (2%)       1 (1%)                   
      Eosinophilic Focus                               3 (4%)       6 (10%)      4 (7%)       3 (5%)       4 (6%)       1 (2%)      
      Focal Cellular Change                                                                   1 (2%)                                
      Hematopoietic Cell Proliferation                                           1 (2%)       3 (5%)       4 (6%)       1 (2%)      
      Infarct                                          1 (1%)                    5 (8%)       3 (5%)                    2 (4%)      
      Inflammation, Chronic                            1 (1%)       1 (2%)                                                          
      Inflammation, Focal, Granulomatous                                         1 (2%)                    1 (1%)       2 (4%)      
      Mineralization                                                                                       1 (1%)                   
      Mixed Cell Focus                                 2 (3%)       2 (3%)       1 (2%)       4 (7%)       1 (1%)       1 (2%)      
      Necrosis                                         4 (6%)       5 (8%)       8 (13%)     13 (22%)     14 (21%)      8 (16%)     
      Biliary Tract, Cyst                                                        1 (2%)                                             
      Biliary Tract, Hyperplasia                                                                           1 (1%)                   
      Centrilobular, Degeneration, Fatty              15 (21%)      6 (10%)     10 (16%)      9 (15%)     12 (18%)      1 (2%)      
      Centrilobular, Necrosis                                                                 2 (3%)                                
   Mesentery                                          (6)          (5)          (9)          (14)         (10)         (13)         
      Fat, Angiectasis                                 1 (17%)      2 (40%)      4 (44%)      6 (43%)      3 (30%)      6 (46%)     
      Fat, Hemorrhage                                                            1 (11%)      3 (21%)      1 (10%)                  
      Fat, Inflammation, Chronic                                    1 (20%)      5 (56%)      2 (14%)      5 (50%)      3 (23%)     
      Fat, Inflammation, Granulomatous                 1 (17%)                                                                      
      Fat, Necrosis                                    2 (33%)      2 (40%)      4 (44%)      2 (14%)      1 (10%)      1 (8%)      
   Pancreas                                           (70)         (49)         (49)         (58)         (66)         (46)         
      Acinus, Angiectasis                                           1 (2%)                                                          
      Acinus, Atrophy                                  1 (1%)                    2 (4%)                    1 (2%)       1 (2%)      
      Acinus, Focal Cellular Change                                 1 (2%)       5 (10%)      4 (7%)       4 (6%)       3 (7%)      
      Acinus, Hyperplasia                              1 (1%)                                                           1 (2%)      
      Acinus, Inflammation, Chronic                                                           1 (2%)                                
      Acinus, Necrosis                                              2 (4%)                                                          
   Pharynx                                                                                   (1)          (1)          (1)          
      Epithelium, Hyperplasia                                                                 1 (100%)     1 (100%)                 
      Palate, Inflammation, Chronic                                                                                     1 (100%)    
   Salivary Glands                                    (70)         (50)         (50)         (48)         (58)         (48)         
      Inflammation                                     1 (1%)                                                                       
      Inflammation, Chronic                                                                                1 (2%)                   
   Stomach, Forestomach                               (70)         (50)         (60)         (60)         (68)         (48)         
      Angiectasis                                                                                                       1 (2%)      
      Cyst Epithelial Inclusion                                                  1 (2%)                                             
      Hyperplasia, Mast Cell                           1 (1%)                                                                       
      Ulcer                                            3 (4%)                    2 (3%)       5 (8%)       4 (6%)       3 (6%)      
      Epithelium, Hyperplasia                          4 (6%)       3 (6%)       3 (5%)       8 (13%)      6 (9%)      10 (21%)     
   Stomach, Glandular                                 (70)         (48)         (60)         (60)         (65)         (44)         
      Inflammation, Suppurative                                     1 (2%)       2 (3%)                                             
      Mineralization                                                             1 (2%)                                             
      Pigmentation, Hemosiderin                        2 (3%)       2 (4%)       3 (5%)       5 (8%)      10 (15%)      2 (5%)      
      Ulcer                                            3 (4%)                    1 (2%)       6 (10%)      9 (14%)      2 (5%)      
   Tooth                                              (9)          (4)          (6)          (3)          (1)          (6)          
      Developmental Malformation                                                              1 (33%)                               
      Inflammation                                     9 (100%)     4 (100%)     6 (100%)     2 (67%)      1 (100%)     6 (100%)    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      200 PPM         
                                                                                                                    SE40            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                                    (1)                                                              
      Inflammation                                                  1 (100%)                                                        
   Heart                                              (70)         (50)         (60)         (58)         (68)         (50)         
      Cardiomyopathy                                   4 (6%)       1 (2%)       6 (10%)      3 (5%)       2 (3%)       2 (4%)      
      Inflammation, Suppurative                        1 (1%)       2 (4%)       1 (2%)       1 (2%)       1 (1%)                   
      Mineralization                                   2 (3%)                                 1 (2%)       3 (4%)                   
      Necrosis                                                      1 (2%)                    2 (3%)                                
      Atrium, Thrombosis                               1 (1%)                                                                       
      Endothelium, Hyperplasia                                      1 (2%)                    2 (3%)       5 (7%)       6 (12%)     
      Pericardium, Inflammation, Chronic                                                                                1 (2%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (70)         (49)         (50)         (47)         (58)         (45)         
      Cyst                                                          2 (4%)       1 (2%)                                             
      Focal Cellular Change                            6 (9%)      13 (27%)      8 (16%)     12 (26%)                   4 (9%)      
      Hyperplasia                                      6 (9%)       8 (16%)      1 (2%)       3 (6%)       4 (7%)       5 (11%)     
      Hypertrophy                                     19 (27%)     16 (33%)     14 (28%)     11 (23%)      6 (10%)     10 (22%)     
   Adrenal Gland, Medulla                             (70)         (48)         (47)         (44)         (54)         (45)         
      Hyperplasia                                                                1 (2%)       1 (2%)       1 (2%)                   
   Islets, Pancreatic                                 (70)         (49)         (49)         (58)         (65)         (46)         
      Hyperplasia                                      2 (3%)       8 (16%)      4 (8%)       3 (5%)       6 (9%)       3 (7%)      
   Parathyroid Gland                                  (58)         (36)         (42)         (40)         (48)         (40)         
      Cyst                                                                                                 1 (2%)       1 (3%)      
   Pituitary Gland                                    (69)         (47)         (47)         (48)         (56)         (44)         
      Pars Distalis, Cyst                              1 (1%)       1 (2%)       4 (9%)       2 (4%)       1 (2%)       1 (2%)      
      Pars Distalis, Hyperplasia                                    1 (2%)                    2 (4%)                    1 (2%)      
      Pars Intermedia, Hyperplasia                                  1 (2%)                                                          
   Thyroid Gland                                      (70)         (50)         (50)         (48)         (57)         (48)         
      Cyst                                                          3 (6%)       1 (2%)       4 (8%)       3 (5%)       1 (2%)      
      Hemorrhage                                                                                                        1 (2%)      
      Hyperplasia                                      1 (1%)                                                                       
      Inflammation                                     2 (3%)                                                           1 (2%)      
      C-Cell, Hyperplasia                                                                     1 (2%)                                
      Follicular Cell, Hyperplasia                     1 (1%)      11 (22%)      4 (8%)       5 (10%)                   2 (4%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      200 PPM         
                                                                                                                    SE40            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (70)         (50)         (50)         (48)         (59)         (49)         
      Angiectasis                                                   1 (2%)                                                          
      Degeneration                                                                            2 (4%)                                
      Hypospermia                                                                1 (2%)                                 4 (8%)      
      Inflammation, Chronic                            1 (1%)       2 (4%)       3 (6%)       2 (4%)       1 (2%)                   
      Muscularis, Hyperplasia                          1 (1%)                                                           1 (2%)      
   Penis                                              (4)          (1)          (4)          (7)          (1)          (4)          
      Hyperplasia                                                                1 (25%)                                            
      Inflammation, Suppurative                        1 (25%)      1 (100%)     3 (75%)      2 (29%)      1 (100%)     1 (25%)     
   Preputial Gland                                    (8)          (2)          (4)          (9)          (6)          (8)          
      Degeneration, Cystic                             1 (13%)                   1 (25%)      3 (33%)      1 (17%)      1 (13%)     
      Hyperplasia                                      2 (25%)                                                                      
      Inflammation, Suppurative                        7 (88%)      2 (100%)     1 (25%)      2 (22%)                   3 (38%)     
      Duct, Dilatation                                                           2 (50%)      1 (11%)                   1 (13%)     
   Prostate                                           (67)         (50)         (48)         (45)         (56)         (44)         
      Hyperplasia                                                                2 (4%)       1 (2%)       1 (2%)                   
      Inflammation                                                  1 (2%)                                                          
      Inflammation, Suppurative                        3 (4%)       2 (4%)       5 (10%)      2 (4%)       1 (2%)       3 (7%)      
   Seminal Vesicle                                    (70)         (48)         (47)         (46)         (54)         (44)         
      Inflammation, Suppurative                        3 (4%)       1 (2%)                                 1 (2%)       2 (5%)      
   Testes                                             (70)         (50)         (51)         (48)         (69)         (50)         
      Angiectasis                                                                                          1 (1%)                   
      Atrophy                                          1 (1%)       3 (6%)       4 (8%)       2 (4%)       6 (9%)       5 (10%)     
      Degeneration                                     1 (1%)                                 3 (6%)       1 (1%)       2 (4%)      
      Hemorrhage                                                                                           1 (1%)                   
      Mineralization                                                1 (2%)       2 (4%)                                 2 (4%)      
      Spermatocele                                                  1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (70)         (50)         (50)         (58)         (69)         (50)         
      Angiectasis                                                                             1 (2%)                                
      Hyperplasia                                     14 (20%)      5 (10%)      7 (14%)     17 (29%)     14 (20%)      9 (18%)     
      Infiltration Cellular, Mast Cell                 1 (1%)                                                                       
   Lymph Node                                         (70)         (50)         (50)         (57)         (68)         (50)         
      Hyperplasia                                                                             1 (2%)       1 (1%)                   
      Iliac, Hyperplasia                                                         1 (2%)       1 (2%)                                
   Lymph Node, Bronchial                              (64)         (42)         (42)         (40)         (46)         (43)         
      Congestion                                                                                                        1 (2%)      
      Hematopoietic Cell Proliferation                              1 (2%)       1 (2%)                                             
      Hyperplasia                                                   2 (5%)       4 (10%)      1 (3%)       3 (7%)       5 (12%)     
   Lymph Node, Mandibular                             (55)         (39)         (38)         (37)         (53)         (42)         
      Hematopoietic Cell Proliferation                                                                                  1 (2%)      
      Hyperplasia                                      5 (9%)       5 (13%)      1 (3%)       4 (11%)      9 (17%)      9 (21%)     
   Lymph Node, Mediastinal                            (37)         (27)         (33)         (39)         (48)         (39)         
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   13                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      200 PPM         
                                                                                                                    SE40            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Congestion                                                                              2 (5%)                                
      Hematopoietic Cell Proliferation                              1 (4%)       1 (3%)       1 (3%)                    1 (3%)      
      Hyperplasia                                      3 (8%)       2 (7%)       4 (12%)                   3 (6%)       1 (3%)      
      Inflammation                                                                                                      1 (3%)      
   Lymph Node, Mesenteric                             (68)         (47)         (47)         (55)         (65)         (44)         
      Angiectasis                                      2 (3%)       9 (19%)      5 (11%)      8 (15%)      7 (11%)      7 (16%)     
      Congestion                                       4 (6%)       7 (15%)      4 (9%)      12 (22%)      6 (9%)       2 (5%)      
      Hematopoietic Cell Proliferation                 1 (1%)       7 (15%)      1 (2%)       4 (7%)       5 (8%)       5 (11%)     
      Hemorrhage                                       1 (1%)       1 (2%)       1 (2%)                                             
      Hyperplasia                                     11 (16%)     17 (36%)     12 (26%)      8 (15%)      5 (8%)       3 (7%)      
      Inflammation                                                               1 (2%)                                             
      Inflammation, Granulomatous                                                             1 (2%)                                
   Spleen                                             (70)         (50)         (51)         (58)         (66)         (47)         
      Depletion Lymphoid                                                                                   1 (2%)                   
      Hematopoietic Cell Proliferation                10 (14%)     15 (30%)      9 (18%)     23 (40%)     21 (32%)     12 (26%)     
      Hyperplasia, Histiocytic                                                   1 (2%)                                             
      Hyperplasia, Lymphoid                                         3 (6%)                    2 (3%)                                
      Necrosis                                                                   1 (2%)       1 (2%)                                
      Pigmentation, Melanin                                                      1 (2%)                                             
      Thrombosis                                                                                                        1 (2%)      
   Thymus                                             (66)         (43)         (42)         (51)         (55)         (41)         
      Hyperplasia, Lymphoid                                         1 (2%)       1 (2%)       2 (4%)                                
      Infiltration Cellular, Mixed Cell                                          1 (2%)                                             
      Necrosis                                        13 (20%)      7 (16%)     18 (43%)     18 (35%)     19 (35%)     14 (34%)     
      Epithelial Cell, Hyperplasia                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (70)         (50)         (51)         (49)         (60)         (50)         
      Acanthosis                                                                                           1 (2%)                   
      Cyst Epithelial Inclusion                                                               1 (2%)                                
      Inflammation, Chronic                                         1 (2%)                    4 (8%)       3 (5%)       2 (4%)      
      Foot, Developmental Malformation                              1 (2%)                                                          
      Hair Follicle, Atrophy                                                                  1 (2%)       1 (2%)                   
      Prepuce, Inflammation, Suppurative               2 (3%)       3 (6%)       7 (14%)      7 (14%)      2 (3%)       5 (10%)     
      Sebaceous Gland, Hyperplasia                                                                         1 (2%)                   
      Subcutaneous Tissue, Angiectasis                              1 (2%)       2 (4%)       1 (2%)       2 (3%)       1 (2%)      
      Subcutaneous Tissue, Edema                                    1 (2%)       1 (2%)       1 (2%)                    1 (2%)      
      Subcutaneous Tissue, Hemorrhage                                            1 (2%)                                             
      Subcutaneous Tissue, Inflammation, Chronic                                              1 (2%)                                
      Subcutaneous Tissue, Inflammation,                                                                                            
          Granulomatous                                1 (1%)                                 1 (2%)                                
      Subcutaneous Tissue, Inflammation,                                                                                            
          Pyogranulomatous                             1 (1%)                    1 (2%)                    1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   14                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      200 PPM         
                                                                                                                    SE40            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (70)         (50)         (50)         (49)         (60)         (50)         
      Developmental Malformation                                                                                        2 (4%)      
      Fibrous Osteodystrophy                           1 (1%)                                                                       
      Fracture                                                                   1 (2%)                                             
      Osteopetrosis                                                              1 (2%)                    1 (2%)       1 (2%)      
      Cranium, Hemorrhage                                                                                  1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (70)         (50)         (50)         (48)         (60)         (50)         
      Developmental Malformation                       1 (1%)                                                                       
      Hemorrhage                                                                              1 (2%)       2 (3%)       4 (8%)      
      Inflammation, Chronic                                                                                             1 (2%)      
      Mineralization                                  33 (47%)     27 (54%)     16 (32%)     15 (31%)     11 (18%)     15 (30%)     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (70)         (48)         (49)         (46)         (53)         (46)         
      Inflammation, Suppurative                        3 (4%)       5 (10%)      2 (4%)       4 (9%)       1 (2%)       1 (2%)      
   Lung                                               (70)         (52)         (62)         (69)         (70)         (50)         
      Angiectasis                                                                                                       1 (2%)      
      Hemorrhage                                       1 (1%)       6 (12%)      7 (11%)      3 (4%)       6 (9%)       3 (6%)      
      Hyperplasia, Lymphoid                                                                                             1 (2%)      
      Inflammation, Chronic, Diffuse                   2 (3%)                    1 (2%)                                             
      Inflammation, Chronic, Focal                                  1 (2%)                    1 (1%)                                
      Inflammation, Suppurative                                                                            1 (1%)       2 (4%)      
      Thrombosis                                       1 (1%)                                 1 (1%)                                
      Alveolar Epithelium, Hyperplasia                 2 (3%)      10 (19%)      6 (10%)     14 (20%)     23 (33%)     18 (36%)     
      Alveolus, Infiltration Cellular, Histiocyte     10 (14%)      4 (8%)       7 (11%)      6 (9%)      12 (17%)     18 (36%)     
      Perivascular, Inflammation, Chronic                           1 (2%)                                                          
      Pleura, Inflammation, Chronic                                              1 (2%)                                 1 (2%)      
   Nose                                               (70)         (50)         (50)         (47)         (59)         (49)         
      Inflammation, Suppurative                       21 (30%)     15 (30%)     21 (42%)     15 (32%)      8 (14%)     14 (29%)     
      Inflammation, Pyogranulomatous                                                                       1 (2%)                   
      Nasolacrimal Duct, Inflammation, Suppurative     2 (3%)       2 (4%)       1 (2%)       9 (19%)      9 (15%)      6 (12%)     
      Olfactory Epithelium, Atrophy                                              1 (2%)       1 (2%)       1 (2%)                   
      Respiratory Epithelium, Metaplasia, Squamous     1 (1%)                                                                       
   Trachea                                            (70)         (49)         (50)         (46)         (55)         (47)         
      Inflammation, Suppurative                       25 (36%)     24 (49%)     19 (38%)     19 (41%)     12 (22%)     20 (43%)     
      Metaplasia, Squamous                             1 (1%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   15                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      6.25 PPM     20 PPM       62.5 PPM     200 PPM      200 PPM         
                                                                                                                    SE40            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)                       (1)          (3)          (8)          (1)          
      Degeneration                                                                                         1 (13%)                  
      Cornea, Hyperplasia                                                                                  3 (38%)                  
      Cornea, Inflammation, Chronic                    1 (100%)                                            6 (75%)                  
      Lens, Degeneration                               1 (100%)                               1 (33%)      1 (13%)                  
   Harderian Gland                                    (63)         (59)         (60)         (57)         (61)         (48)         
      Hyperplasia                                      1 (2%)       3 (5%)       4 (7%)       6 (11%)     14 (23%)      4 (8%)      
      Inflammation, Suppurative                                                  1 (2%)                                             
   Zymbal's Gland                                     (2)                                                              (1)          
      Cyst                                             1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (70)         (53)         (54)         (50)         (69)         (48)         
      Cyst                                             4 (6%)       8 (15%)      1 (2%)       2 (4%)       1 (1%)                   
      Hydronephrosis                                                2 (4%)       1 (2%)       1 (2%)                                
      Hyperplasia, Mast Cell                           1 (1%)                                                                       
      Infarct                                                       1 (2%)       1 (2%)                    1 (1%)                   
      Infiltration Cellular, Histiocyte                                                                                 1 (2%)      
      Inflammation, Suppurative                        1 (1%)       1 (2%)       4 (7%)       1 (2%)       3 (4%)       1 (2%)      
      Metaplasia, Osseous                              1 (1%)       1 (2%)                                                          
      Nephropathy                                     35 (50%)     38 (72%)     26 (48%)     20 (40%)     13 (19%)     12 (25%)     
      Pigmentation, Hemosiderin                                                                                         1 (2%)      
      Capsule, Inflammation, Chronic                                                          1 (2%)                                
      Papilla, Necrosis                                1 (1%)       2 (4%)                                                          
      Renal Tubule, Hyperplasia                        2 (3%)                                 3 (6%)       1 (1%)       4 (8%)      
      Renal Tubule, Mineralization                                               2 (4%)                                             
   Urethra                                            (2)          (2)          (1)          (6)          (2)          (1)          
      Inflammation, Suppurative                                     1 (50%)      1 (100%)                  1 (50%)                  
      Necrosis                                                      1 (50%)                                                         
   Urinary Bladder                                    (70)         (48)         (50)         (49)         (58)         (43)         
      Calculus Micro Observation Only                                                         1 (2%)                                
      Dilatation                                       9 (13%)      3 (6%)       8 (16%)      8 (16%)      5 (9%)       8 (19%)     
      Inflammation                                     1 (1%)       1 (2%)       3 (6%)       1 (2%)                    1 (2%)      
      Necrosis                                                      1 (2%)                                                          
      Transitional Epithelium, Hyperplasia                                       1 (2%)                                 2 (5%)      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   16                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          312 PPM      625 PPM      625 PPM      625 PPM                                   
                                                   SE52                      SE13         SE 26                                     
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           90           50           50                                     
  Scheduled Sacrifice                                              17                                                               
  Early Deaths                                                                                                                      
    Moribund                                          25           33           25           22                                     
    Dead                                              24           39           19           28                                     
    Accident                                                        1            1                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                 1                         5                                                  
  Animals Examined Microscopically                    50           90           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (27)         (57)         (32)         (32)                                   
      Hyperplasia                                                                1 (3%)                                             
   Intestine Large                                    (48)         (82)         (46)         (47)                                   
      Anus, Inflammation, Suppurative                               1 (1%)                                                          
   Intestine Large, Colon                             (44)         (78)         (44)         (45)                                   
      Necrosis                                                      1 (1%)                    1 (2%)                                
   Intestine Small, Duodenum                          (38)         (67)         (35)         (32)                                   
      Hemorrhage                                                    1 (1%)                    1 (3%)                                
   Intestine Small, Ileum                             (40)         (68)         (37)         (40)                                   
      Angiectasis                                      1 (3%)                                                                       
      Peyer's Patch, Hyperplasia                       1 (3%)                                                                       
   Intestine Small, Jejunum                           (37)         (65)         (40)         (41)                                   
      Hemorrhage                                                                              1 (2%)                                
      Peyer's Patch, Necrosis                                                                 1 (2%)                                
   Liver                                              (50)         (89)         (49)         (50)                                   
      Angiectasis                                      1 (2%)                    1 (2%)                                             
      Basophilic Focus                                 2 (4%)       2 (2%)       1 (2%)                                             
      Degeneration, Fatty                              1 (2%)       2 (2%)                    2 (4%)                                
      Eosinophilic Focus                               4 (8%)       1 (1%)       1 (2%)       3 (6%)                                
      Hematopoietic Cell Proliferation                 4 (8%)       7 (8%)       3 (6%)       9 (18%)                               
      Hyperplasia, Focal                                            1 (1%)                                                          
      Infarct                                          1 (2%)                    3 (6%)                                             
      Inflammation, Chronic                                                                   1 (2%)                                
      Inflammation, Focal, Granulomatous                                         1 (2%)                                             
      Mineralization                                                2 (2%)                                                          
      Necrosis                                        13 (26%)     19 (21%)     10 (20%)     14 (28%)                               
      Thrombosis                                       2 (4%)                                                                       
      Biliary Tract, Cyst                                                        2 (4%)                                             
      Biliary Tract, Hyperplasia                       2 (4%)                                                                       
      Biliary Tract, Hypertrophy                                                              1 (2%)                                
      Centrilobular, Degeneration, Fatty               4 (8%)       8 (9%)       1 (2%)       1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   17                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          312 PPM      625 PPM      625 PPM      625 PPM                                   
                                                   SE52                      SE13         SE 26                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Centrilobular, Necrosis                          7 (14%)      7 (8%)       1 (2%)       1 (2%)                                
   Mesentery                                          (13)         (6)          (11)         (4)                                    
      Fat, Angiectasis                                 3 (23%)                   2 (18%)                                            
      Fat, Hemorrhage                                  1 (8%)       1 (17%)      1 (9%)       1 (25%)                               
      Fat, Inflammation, Chronic                       1 (8%)       2 (33%)                                                         
      Fat, Necrosis                                                 1 (17%)      2 (18%)      1 (25%)                               
   Pancreas                                           (49)         (89)         (46)         (49)                                   
      Acinus, Atrophy                                  1 (2%)                                 1 (2%)                                
      Acinus, Focal Cellular Change                    2 (4%)       3 (3%)                                                          
      Acinus, Hyperplasia                              3 (6%)                                                                       
      Acinus, Inflammation, Chronic                                 1 (1%)                                                          
      Acinus, Vacuolization Cytoplasmic                1 (2%)                                                                       
   Pharynx                                                         (2)                       (2)                                    
      Palate, Inflammation, Chronic                                 1 (50%)                                                         
   Salivary Glands                                    (48)         (86)         (50)         (50)                                   
      Hemorrhage                                                    1 (1%)                                                          
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Inflammation                                                               2 (4%)                                             
   Stomach, Forestomach                               (48)         (89)         (50)         (50)                                   
      Hemorrhage                                                    1 (1%)                                                          
      Ulcer                                            4 (8%)      13 (15%)      2 (4%)       2 (4%)                                
      Epithelium, Hyperplasia                         20 (42%)     50 (56%)      8 (16%)     15 (30%)                               
   Stomach, Glandular                                 (47)         (83)         (44)         (47)                                   
      Mineralization                                                1 (1%)                                                          
      Pigmentation, Hemosiderin                        7 (15%)      7 (8%)       3 (7%)       4 (9%)                                
      Ulcer                                            3 (6%)       6 (7%)       1 (2%)       4 (9%)                                
   Tooth                                                                        (4)                                                 
      Inflammation                                                               3 (75%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                                    (1)                                                              
      Mineralization                                                1 (100%)                                                        
   Heart                                              (50)         (90)         (50)         (50)                                   
      Cardiomyopathy                                   1 (2%)       2 (2%)       1 (2%)       4 (8%)                                
      Hemorrhage                                                    2 (2%)                    1 (2%)                                
      Inflammation, Suppurative                                                               2 (4%)                                
      Mineralization                                   6 (12%)     21 (23%)      9 (18%)     14 (28%)                               
      Necrosis                                         1 (2%)       1 (1%)                    1 (2%)                                
      Atrium, Thrombosis                               1 (2%)       3 (3%)                    1 (2%)                                
      Endothelium, Hyperplasia                         3 (6%)       8 (9%)       7 (14%)      7 (14%)                               
      Pericardium, Inflammation, Chronic                                         1 (2%)                                             
      Ventricle, Thrombosis                                                                   1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   18                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          312 PPM      625 PPM      625 PPM      625 PPM                                   
                                                   SE52                      SE13         SE 26                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (49)         (90)         (50)         (50)                                   
      Focal Cellular Change                            1 (2%)                                                                       
      Hematocyst                                       1 (2%)                                                                       
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hyperplasia                                      4 (8%)                                 1 (2%)                                
      Hypertrophy                                     12 (24%)      5 (6%)       9 (18%)      2 (4%)                                
   Adrenal Gland, Medulla                             (48)         (86)         (49)         (48)                                   
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
   Islets, Pancreatic                                 (49)         (87)         (45)         (48)                                   
      Cytoplasmic Alteration                           1 (2%)                                                                       
      Hyperplasia                                      1 (2%)       1 (1%)                    1 (2%)                                
   Parathyroid Gland                                  (44)         (69)         (33)         (37)                                   
      Cyst                                                          2 (3%)                                                          
   Pituitary Gland                                    (43)         (78)         (43)         (43)                                   
      Pars Distalis, Cyst                              1 (2%)       1 (1%)       2 (5%)                                             
      Pars Distalis, Hemorrhage                                                  1 (2%)                                             
      Pars Distalis, Hyperplasia                                                 1 (2%)                                             
   Thyroid Gland                                      (49)         (86)         (50)         (49)                                   
      Cyst                                             3 (6%)                    1 (2%)       1 (2%)                                
      Follicular Cell, Hyperplasia                     1 (2%)                    2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                               (2)                                                              
      Inflammation, Suppurative                                     2 (100%)                                                        
   Epididymis                                         (50)         (87)         (49)         (50)                                   
      Angiectasis                                                   1 (1%)                    1 (2%)                                
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Inflammation, Chronic                            3 (6%)                    1 (2%)                                             
   Preputial Gland                                    (4)          (2)          (10)         (6)                                    
      Angiectasis                                      1 (25%)                                                                      
      Degeneration, Cystic                                                       1 (10%)                                            
      Hyperplasia                                                                2 (20%)                                            
      Inflammation, Suppurative                                     2 (100%)     6 (60%)      3 (50%)                               
   Prostate                                           (48)         (83)         (48)         (47)                                   
      Hyperplasia                                                   1 (1%)                                                          
      Inflammation                                                  1 (1%)                    1 (2%)                                
      Inflammation, Suppurative                                     1 (1%)       2 (4%)                                             
      Mineralization                                                1 (1%)                                                          
   Seminal Vesicle                                    (47)         (84)         (42)         (47)                                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   19                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          312 PPM      625 PPM      625 PPM      625 PPM                                   
                                                   SE52                      SE13         SE 26                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Inflammation, Suppurative                                                  1 (2%)                                             
   Testes                                             (50)         (89)         (50)         (50)                                   
      Angiectasis                                      4 (8%)                    1 (2%)                                             
      Atrophy                                          3 (6%)      63 (71%)      3 (6%)       5 (10%)                               
      Degeneration                                                                            2 (4%)                                
      Interstitial Cell, Hyperplasia                                             1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (90)         (48)         (49)                                   
      Angiectasis                                      1 (2%)                                                                       
      Atrophy                                          5 (10%)     28 (31%)      3 (6%)       2 (4%)                                
      Fibrosis                                         1 (2%)                                                                       
      Hyperplasia                                      9 (18%)      5 (6%)      11 (23%)      8 (16%)                               
      Hyperplasia, Histiocytic                                      1 (1%)                                                          
      Infiltration Cellular, Megakaryocyte                          1 (1%)                                                          
      Necrosis                                                      1 (1%)                    1 (2%)                                
   Lymph Node                                         (50)         (90)         (49)         (50)                                   
      Necrosis                                                      1 (1%)                                                          
      Axillary, Hematopoietic Cell Proliferation                                              1 (2%)                                
      Iliac, Hematopoietic Cell Proliferation                                                 1 (2%)                                
      Iliac, Hyperplasia                                                         1 (2%)                                             
      Inguinal, Hematopoietic Cell Proliferation                                              1 (2%)                                
      Pancreatic, Hyperplasia                                                                 1 (2%)                                
      Renal, Mineralization                                         1 (1%)                                                          
   Lymph Node, Bronchial                              (37)         (53)         (40)         (41)                                   
      Hematopoietic Cell Proliferation                 2 (5%)                                 2 (5%)                                
      Hyperplasia                                      1 (3%)                    1 (3%)                                             
   Lymph Node, Mandibular                             (31)         (70)         (39)         (43)                                   
      Hematopoietic Cell Proliferation                              1 (1%)                    2 (5%)                                
      Hyperplasia                                      3 (10%)                   7 (18%)                                            
      Hyperplasia, Histiocytic                                      2 (3%)                                                          
      Hyperplasia, Plasma Cell                                      4 (6%)                                                          
      Mineralization                                                2 (3%)                                                          
      Necrosis                                                      6 (9%)                    1 (2%)                                
   Lymph Node, Mediastinal                            (41)         (68)         (39)         (44)                                   
      Congestion                                                    1 (1%)                    1 (2%)                                
      Hematopoietic Cell Proliferation                 2 (5%)       2 (3%)                    3 (7%)                                
      Hyperplasia                                      2 (5%)                    1 (3%)                                             
   Lymph Node, Mesenteric                             (44)         (84)         (43)         (48)                                   
      Angiectasis                                      1 (2%)                    2 (5%)       1 (2%)                                
      Congestion                                       1 (2%)                    2 (5%)                                             
      Hematopoietic Cell Proliferation                 2 (5%)                    4 (9%)       1 (2%)                                
      Hemorrhage                                                    1 (1%)                                                          
      Hyperplasia                                      1 (2%)                                                                       
      Hyperplasia, Histiocytic                                      3 (4%)                                                          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   20                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          312 PPM      625 PPM      625 PPM      625 PPM                                   
                                                   SE52                      SE13         SE 26                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Inflammation                                                  1 (1%)                    1 (2%)                                
      Necrosis                                                      1 (1%)                                                          
   Spleen                                             (48)         (87)         (49)         (50)                                   
      Angiectasis                                                                1 (2%)                                             
      Depletion Lymphoid                               1 (2%)       2 (2%)                                                          
      Hematopoietic Cell Proliferation                21 (44%)     16 (18%)     18 (37%)     18 (36%)                               
      Hemorrhage                                                                              1 (2%)                                
      Hyperplasia, Histiocytic                                      2 (2%)                                                          
      Hyperplasia, Lymphoid                                                      2 (4%)                                             
      Mineralization                                                1 (1%)                                                          
      Necrosis                                                      2 (2%)                    1 (2%)                                
   Thymus                                             (37)         (78)         (37)         (40)                                   
      Hyperplasia, Neutrophil                                       1 (1%)                                                          
      Infiltration Cellular, Mixed Cell                                                       1 (3%)                                
      Inflammation, Suppurative                        1 (3%)                                                                       
      Necrosis                                        30 (81%)     17 (22%)     10 (27%)     10 (25%)                               
      Mediastinum, Necrosis                                                                   1 (3%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (49)         (90)         (50)         (50)                                   
      Acanthosis                                                    1 (1%)                                                          
      Cyst Epithelial Inclusion                        1 (2%)                                 1 (2%)                                
      Inflammation, Chronic                            1 (2%)                                 1 (2%)                                
      Necrosis                                                      1 (1%)                                                          
      Hair Follicle, Atrophy                           1 (2%)                                 1 (2%)                                
      Hair Follicle, Inflammation, Suppurative                      1 (1%)                                                          
      Prepuce, Inflammation, Suppurative                            1 (1%)       2 (4%)                                             
      Sebaceous Gland, Hyperplasia                                               1 (2%)                                             
      Subcutaneous Tissue, Angiectasis                 1 (2%)                                                                       
      Subcutaneous Tissue, Edema                       1 (2%)                    1 (2%)                                             
      Subcutaneous Tissue, Hemorrhage                  3 (6%)       1 (1%)       2 (4%)       1 (2%)                                
      Subcutaneous Tissue, Inflammation,                                                                                            
          Granulomatous                                             2 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   21                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          312 PPM      625 PPM      625 PPM      625 PPM                                   
                                                   SE52                      SE13         SE 26                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (90)         (50)         (50)                                   
      Hemorrhage                                       6 (12%)     12 (13%)      2 (4%)       3 (6%)                                
      Mineralization                                   9 (18%)      9 (10%)     12 (24%)      6 (12%)                               
      Necrosis                                         1 (2%)                                 2 (4%)                                
      Pigmentation, Hemosiderin                        1 (2%)                                                                       
   Spinal Cord                                                     (12)         (1)          (2)                                    
      Hemorrhage                                                    2 (17%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (49)         (88)         (49)         (47)                                   
      Hyperplasia                                                   1 (1%)                                                          
      Inflammation                                                  1 (1%)                                                          
      Inflammation, Suppurative                        1 (2%)                                                                       
      Metaplasia, Squamous                                                                    1 (2%)                                
   Lung                                               (50)         (90)         (50)         (50)                                   
      Hemorrhage                                       7 (14%)     14 (16%)      5 (10%)     10 (20%)                               
      Inflammation, Chronic, Focal                     1 (2%)                    1 (2%)       2 (4%)                                
      Inflammation, Suppurative                                                               2 (4%)                                
      Thrombosis                                                    1 (1%)                    1 (2%)                                
      Alveolar Epithelium, Hyperplasia                14 (28%)     22 (24%)     10 (20%)     11 (22%)                               
      Alveolus, Infiltration Cellular, Histiocyte     12 (24%)      2 (2%)       9 (18%)      3 (6%)                                
      Alveolus, Pigmentation, Hemosiderin              1 (2%)       1 (1%)       1 (2%)                                             
      Bronchiole, Epithelium, Hyperplasia              1 (2%)                                                                       
      Pleura, Inflammation, Chronic                                 1 (1%)                    1 (2%)                                
   Nose                                               (49)         (88)         (50)         (50)                                   
      Inflammation, Suppurative                        7 (14%)      2 (2%)       7 (14%)      1 (2%)                                
      Nasolacrimal Duct, Inflammation, Suppurative     8 (16%)                   8 (16%)      1 (2%)                                
      Nerve, Hyperplasia                                                         1 (2%)                                             
      Olfactory Epithelium, Atrophy                    2 (4%)       4 (5%)       2 (4%)       1 (2%)                                
      Olfactory Epithelium, Metaplasia, Squamous                    2 (2%)                                                          
      Respiratory Epithelium, Metaplasia, Squamous     1 (2%)                                                                       
   Trachea                                            (47)         (84)         (48)         (48)                                   
      Inflammation, Suppurative                       12 (26%)                  11 (23%)      7 (15%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (4)          (6)          (4)          (3)                                    
      Degeneration                                                  1 (17%)      1 (25%)                                            
      Cornea, Hyperplasia                              1 (25%)                                                                      
      Cornea, Inflammation, Chronic                    2 (50%)                   2 (50%)                                            
   Harderian Gland                                    (48)         (53)         (42)         (36)                                   
      Hyperplasia                                      6 (13%)      5 (9%)       3 (7%)       7 (19%)                               
      Inflammation, Chronic                            1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   22                                                              
NTP Experiment-Test: 05134-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     1,3 BUTADIENE (BUTADIENE)                                 Date: 09/17/94  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 11:36:58  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          312 PPM      625 PPM      625 PPM      625 PPM                                   
                                                   SE52                      SE13         SE 26                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (90)         (50)         (50)                                   
      Cyst                                             1 (2%)                    1 (2%)                                             
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hemorrhage                                                    2 (2%)       1 (2%)       2 (4%)                                
      Hydronephrosis                                                1 (1%)                                                          
      Infarct                                                                                 1 (2%)                                
      Inflammation, Suppurative                                     1 (1%)       4 (8%)       1 (2%)                                
      Metaplasia, Osseous                                                        1 (2%)                                             
      Nephropathy                                      4 (8%)       5 (6%)      10 (20%)      4 (8%)                                
      Capsule, Angiectasis                             1 (2%)                                                                       
      Capsule, Inflammation, Chronic                   1 (2%)                                                                       
      Papilla, Necrosis                                             1 (1%)                                                          
      Pelvis, Hyperplasia                                           2 (2%)                                                          
      Pelvis, Mineralization                                        3 (3%)                                                          
      Renal Tubule, Hyperplasia                        1 (2%)       1 (1%)       1 (2%)       2 (4%)                                
      Renal Tubule, Mineralization                                  4 (4%)       1 (2%)                                             
   Urinary Bladder                                    (47)         (83)         (46)         (48)                                   
      Dilatation                                                    1 (1%)       3 (7%)                                             
      Hemorrhage                                                    1 (1%)                                                          
      Inflammation                                                  3 (4%)       1 (2%)                                             
      Transitional Epithelium, Hyperplasia             1 (2%)       2 (2%)                                                          
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   23                                                              
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------