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TDMS Study 05156-05 Pathology Tables

NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51

                                                           CORE STUDY




       Facility:  Battelle Northwest

       Chemical CAS #:  10026-24-1

       Lock Date:  07/15/94

       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: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                19           20           20           17                                     
    Natural Death                                      3            4            4            3                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                28           25           26           30                                     
  Other                                                             1                                                               
  Animals Examined Microscopically                    50           49           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (50)         (49)         (50)         (50)                                   
      Inflammation, Suppurative                                                  1 (2%)                                             
   Intestine Large, Cecum                             (48)         (45)         (47)         (47)                                   
      Necrosis                                                                   1 (2%)                                             
   Liver                                              (50)         (49)         (50)         (49)                                   
      Angiectasis                                      6 (12%)      4 (8%)       1 (2%)       2 (4%)                                
      Basophilic Focus                                39 (78%)     37 (76%)     45 (90%)     41 (84%)                               
      Clear Cell Focus                                 7 (14%)      6 (12%)      5 (10%)     11 (22%)                               
      Cyst                                                                       1 (2%)                                             
      Degeneration, Fatty                              8 (16%)      9 (18%)      8 (16%)      2 (4%)                                
      Eosinophilic Focus                               4 (8%)       1 (2%)       1 (2%)       2 (4%)                                
      Hepatodiaphragmatic Nodule                       6 (12%)      6 (12%)      8 (16%)      4 (8%)                                
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Mixed Cell Focus                                11 (22%)     11 (22%)     18 (36%)     15 (31%)                               
      Necrosis                                                      1 (2%)                                                          
      Regeneration                                                  1 (2%)       2 (4%)                                             
      Thrombosis                                       1 (2%)                                                                       
      Bile Duct, Hyperplasia                           5 (10%)      6 (12%)      9 (18%)      7 (14%)                               
      Centrilobular, Necrosis                          5 (10%)      6 (12%)      7 (14%)      5 (10%)                               
   Mesentery                                          (5)          (8)          (6)          (13)                                   
      Inflammation, Chronic Active                                                            1 (8%)                                
      Artery, Inflammation, Chronic Active                          1 (13%)                                                         
      Fat, Necrosis                                    5 (100%)     6 (75%)      6 (100%)    12 (92%)                               
   Pancreas                                           (49)         (49)         (50)         (48)                                   
      Atrophy                                         22 (45%)     11 (22%)     16 (32%)     16 (33%)                               
      Basophilic Focus                                                                        3 (6%)                                
      Hyperplasia                                                                             1 (2%)                                
      Artery, Inflammation                                                       1 (2%)                                             
   Salivary Glands                                    (50)         (49)         (50)         (50)                                   
      Atrophy                                          3 (6%)       4 (8%)       1 (2%)                                             
   Stomach, Forestomach                               (50)         (49)         (50)         (50)                                   
      Hyperplasia, Basal Cell                                       1 (2%)                                                          
      Hyperplasia, Squamous                                                      1 (2%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Necrosis                                         3 (6%)       2 (4%)       1 (2%)       1 (2%)                                
   Stomach, Glandular                                 (49)         (49)         (49)         (48)                                   
      Mineralization                                   1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Necrosis                                         4 (8%)                    1 (2%)                                             
   Tooth                                                           (2)                       (1)                                    
      Developmental Malformation                                    1 (50%)                                                         
      Inflammation, Chronic Active                                  1 (50%)                   1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                                                 (1)                                                 
      Aorta, Inflammation, Chronic Active                                        1 (100%)                                           
   Heart                                              (50)         (49)         (50)         (50)                                   
      Cardiomyopathy                                  29 (58%)     24 (49%)     29 (58%)     23 (46%)                               
      Atrium, Thrombosis                                            1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (49)         (50)         (49)                                   
      Hyperplasia                                     21 (43%)     21 (43%)     25 (50%)     23 (47%)                               
      Hypertrophy                                      5 (10%)      3 (6%)       8 (16%)      9 (18%)                               
      Necrosis                                         1 (2%)                                                                       
      Vacuolization Cytoplasmic                       11 (22%)      5 (10%)     10 (20%)     12 (24%)                               
   Adrenal Medulla                                    (48)         (49)         (50)         (48)                                   
      Hyperplasia                                      8 (17%)      7 (14%)     11 (22%)     13 (27%)                               
   Pituitary Gland                                    (50)         (49)         (50)         (49)                                   
      Pars Distalis, Angiectasis                                                 2 (4%)                                             
      Pars Distalis, Cyst                                                                     1 (2%)                                
      Pars Distalis, Hyperplasia                       5 (10%)      5 (10%)      8 (16%)      5 (10%)                               
   Thyroid Gland                                      (49)         (49)         (50)         (48)                                   
      C-Cell, Hyperplasia                             37 (76%)     42 (86%)     37 (74%)     38 (79%)                               
      Follicular Cell, Hyperplasia                     2 (4%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (48)         (48)         (49)                                   
      Hyperplasia                                      2 (4%)       1 (2%)       1 (2%)       2 (4%)                                
      Inflammation, Chronic Active                     2 (4%)       6 (13%)      2 (4%)       6 (12%)                               
   Ovary                                              (50)         (49)         (50)         (49)                                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Cyst                                             5 (10%)      1 (2%)       3 (6%)                                             
   Uterus                                             (50)         (49)         (50)         (49)                                   
      Hydrometra                                                                              2 (4%)                                
      Cervix, Hypertrophy                                           1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (49)         (50)         (50)                                   
      Atrophy                                          2 (4%)                                 1 (2%)                                
      Hyperplasia, Histiocytic                                                   1 (2%)       1 (2%)                                
   Lymph Node                                         (2)          (3)          (3)          (2)                                    
      Renal, Hemorrhage                                             1 (33%)                                                         
   Lymph Node, Mandibular                             (44)         (40)         (47)         (45)                                   
      Infiltration Cellular, Plasma Cell                                                      1 (2%)                                
   Lymph Node, Mesenteric                             (49)         (49)         (50)         (48)                                   
      Hemorrhage                                                    1 (2%)                    1 (2%)                                
      Infiltration Cellular, Eosinophil                                                       1 (2%)                                
   Lymph Node, Mediastinal                            (43)         (38)         (43)         (45)                                   
      Hemorrhage                                       1 (2%)                                 1 (2%)                                
      Infiltration Cellular, Plasma Cell                                         1 (2%)       1 (2%)                                
   Spleen                                             (49)         (48)         (50)         (49)                                   
      Accessory Spleen                                 1 (2%)       2 (4%)                                                          
      Fibrosis                                                      4 (8%)       2 (4%)                                             
      Hematopoietic Cell Proliferation                 3 (6%)       2 (4%)       4 (8%)       3 (6%)                                
      Hemorrhage                                       2 (4%)                    3 (6%)       1 (2%)                                
      Hyperplasia, Focal                                                                      1 (2%)                                
      Necrosis                                                                                1 (2%)                                
      Thrombosis                                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (49)         (50)         (49)                                   
      Galactocele                                                   2 (4%)       1 (2%)       1 (2%)                                
      Inflammation, Chronic Active                                                            1 (2%)                                
   Skin                                               (50)         (49)         (50)         (50)                                   
      Hyperkeratosis                                                1 (2%)                                                          
      Inflammation, Chronic                                                                   1 (2%)                                
      Inflammation, Chronic Active                                  4 (8%)       3 (6%)       3 (6%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (49)         (50)         (50)                                   
      Hyperostosis                                     4 (8%)       5 (10%)      5 (10%)      3 (6%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (49)         (50)         (50)                                   
      Gliosis                                                                                 1 (2%)                                
      Hemorrhage                                       2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (49)         (50)         (50)                                   
      Epiglottis, Metaplasia, Squamous                 1 (2%)      22 (45%)     39 (78%)     48 (96%)                               
   Lung                                               (50)         (49)         (50)         (50)                                   
      Congestion, Chronic                                           1 (2%)                                                          
      Cyst                                                                       1 (2%)                                             
      Metaplasia, Osseous                                                                     1 (2%)                                
      Metaplasia, Squamous                                          1 (2%)       8 (16%)      3 (6%)                                
      Pigmentation, Hemosiderin                                     1 (2%)                                                          
      Proteinosis                                                  36 (73%)     49 (98%)     49 (98%)                               
      Alveolar Epithelium, Hyperplasia                15 (30%)      7 (14%)     20 (40%)     33 (66%)                               
      Alveolar Epithelium, Hyperplasia, Atypical                                 3 (6%)       5 (10%)                               
      Alveolar Epithelium, Metaplasia                  2 (4%)      47 (96%)     50 (100%)    49 (98%)                               
      Alveolus, Inflammation, Granulomatous            9 (18%)     47 (96%)     50 (100%)    49 (98%)                               
      Interstitium, Fibrosis                           7 (14%)     47 (96%)     50 (100%)    49 (98%)                               
      Perivascular, Inflammation, Chronic Active                                              1 (2%)                                
   Nose                                               (50)         (49)         (50)         (50)                                   
      Inflammation, Suppurative                        6 (12%)     10 (20%)      2 (4%)       4 (8%)                                
      Thrombosis                                       4 (8%)       4 (8%)       3 (6%)       2 (4%)                                
      Lateral Wall, Hyperplasia                        1 (2%)       8 (16%)     26 (52%)     38 (76%)                               
      Lateral Wall, Metaplasia, Squamous               1 (2%)       1 (2%)       4 (8%)      10 (20%)                               
      Nasolacrimal Duct, Metaplasia, Squamous                       1 (2%)                                                          
      Olfactory Epithelium, Atrophy                    5 (10%)     29 (59%)     46 (92%)     47 (94%)                               
      Olfactory Epithelium, Metaplasia                 2 (4%)       2 (4%)       3 (6%)      40 (80%)                               
      Respiratory Epithelium, Hyperplasia, Focal       1 (2%)                                                                       
      Respiratory Epithelium, Metaplasia, Squamous     2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)          (5)          (3)          (3)                                    
      Cataract                                         1 (100%)     4 (80%)      3 (100%)     2 (67%)                               
      Cornea, Edema                                                 1 (20%)                                                         
      Retina, Atrophy                                  1 (100%)     4 (80%)      3 (100%)     1 (33%)                               
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (49)         (50)         (48)                                   
      Hyperplasia, Stromal                                                                    1 (2%)                                
      Infarct                                          1 (2%)                    2 (4%)       2 (4%)                                
      Nephropathy                                     47 (96%)     48 (98%)     45 (90%)     48 (100%)                              
      Renal Tubule, Hyperplasia                                                  1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                30           34           26           34                                     
    Natural Death                                      3            1            3            1                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                17           15           21           15                                     
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (50)         (50)         (50)         (50)                                   
      Inflammation, Suppurative                                                  1 (2%)                                             
   Intestine Small, Jejunum                           (49)         (49)         (47)         (49)                                   
      Inflammation, Chronic Active                                  1 (2%)                                                          
   Liver                                              (50)         (50)         (48)         (50)                                   
      Angiectasis                                      5 (10%)      1 (2%)                    1 (2%)                                
      Basophilic Focus                                13 (26%)     16 (32%)     23 (48%)     21 (42%)                               
      Clear Cell Focus                                 8 (16%)      5 (10%)      8 (17%)      6 (12%)                               
      Degeneration, Cystic                            10 (20%)     11 (22%)     16 (33%)     10 (20%)                               
      Degeneration, Fatty                              6 (12%)      5 (10%)      5 (10%)      6 (12%)                               
      Eosinophilic Focus                               2 (4%)                    3 (6%)       5 (10%)                               
      Hepatodiaphragmatic Nodule                       1 (2%)       4 (8%)       4 (8%)       6 (12%)                               
      Mixed Cell Focus                                 3 (6%)       3 (6%)       4 (8%)       5 (10%)                               
      Necrosis                                                      2 (4%)       1 (2%)       1 (2%)                                
      Regeneration                                     3 (6%)       1 (2%)       1 (2%)       1 (2%)                                
      Thrombosis                                       1 (2%)       1 (2%)                                                          
      Bile Duct, Hyperplasia                          41 (82%)     42 (84%)     34 (71%)     35 (70%)                               
      Centrilobular, Necrosis                         17 (34%)     19 (38%)      5 (10%)     11 (22%)                               
   Mesentery                                          (21)         (14)         (11)         (14)                                   
      Fat, Hemorrhage                                  1 (5%)                    1 (9%)                                             
      Fat, Necrosis                                   20 (95%)     11 (79%)      9 (82%)     13 (93%)                               
   Pancreas                                           (50)         (50)         (48)         (50)                                   
      Angiectasis                                                   1 (2%)                                                          
      Atrophy                                         25 (50%)     25 (50%)     20 (42%)     28 (56%)                               
      Basophilic Focus                                 3 (6%)       2 (4%)       6 (13%)      3 (6%)                                
      Hyperplasia                                      2 (4%)       1 (2%)       4 (8%)       1 (2%)                                
      Metaplasia, Hepatocyte                                        1 (2%)                                                          
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Atrophy                                          2 (4%)       2 (4%)                    1 (2%)                                
   Stomach, Forestomach                               (50)         (50)         (49)         (50)                                   
      Hyperplasia, Basal Cell                                       1 (2%)                                                          
      Hyperplasia, Squamous                                         1 (2%)                                                          
      Necrosis                                         6 (12%)      5 (10%)     10 (20%)      3 (6%)                                
   Stomach, Glandular                                 (50)         (50)         (48)         (50)                                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Acute                                           1 (2%)                                                          
      Mineralization                                   1 (2%)       2 (4%)       1 (2%)       1 (2%)                                
      Necrosis                                         3 (6%)       2 (4%)       5 (10%)      2 (4%)                                
   Tongue                                             (1)                                    (2)                                    
      Hyperplasia, Squamous                            1 (100%)                               1 (50%)                               
      Epithelium, Cyst                                                                        1 (50%)                               
   Tooth                                                                        (1)          (1)                                    
      Developmental Malformation                                                 1 (100%)     1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                                                              (1)                                    
      Aorta, Mineralization                                                                   1 (100%)                              
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                  38 (76%)     46 (92%)     45 (90%)     38 (76%)                               
      Atrium, Thrombosis                               2 (4%)       4 (8%)       1 (2%)       4 (8%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (48)         (50)                                   
      Hyperplasia                                     26 (52%)     24 (48%)     26 (54%)     24 (48%)                               
      Hypertrophy                                      2 (4%)       5 (10%)      5 (10%)      5 (10%)                               
      Necrosis                                         2 (4%)       1 (2%)                    3 (6%)                                
      Thrombosis                                                                 1 (2%)                                             
      Vacuolization Cytoplasmic                        6 (12%)      4 (8%)       3 (6%)       3 (6%)                                
   Adrenal Medulla                                    (50)         (50)         (49)         (50)                                   
      Cyst                                                                                    1 (2%)                                
      Hyperplasia                                     34 (68%)     23 (46%)     29 (59%)     30 (60%)                               
   Islets, Pancreatic                                 (50)         (50)         (48)         (50)                                   
      Hyperplasia                                                   1 (2%)                                                          
   Parathyroid Gland                                  (48)         (48)         (49)         (49)                                   
      Hyperplasia                                      1 (2%)       1 (2%)       3 (6%)       1 (2%)                                
   Pituitary Gland                                    (49)         (49)         (50)         (49)                                   
      Pars Distalis, Hyperplasia                       4 (8%)       5 (10%)      4 (8%)       5 (10%)                               
   Thyroid Gland                                      (49)         (50)         (48)         (50)                                   
      C-Cell, Hyperplasia                             31 (63%)     32 (64%)     32 (67%)     34 (68%)                               
      Follicular Cell, Hyperplasia                     2 (4%)                    1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm                                  1 (2%)       3 (6%)                                                          
   Preputial Gland                                    (50)         (50)         (49)         (50)                                   
      Hyperplasia                                      1 (2%)                                                                       
      Inflammation, Chronic Active                    11 (22%)     10 (20%)      3 (6%)      12 (24%)                               
   Prostate                                           (50)         (50)         (49)         (50)                                   
      Hyperplasia                                     12 (24%)      8 (16%)      5 (10%)      9 (18%)                               
      Inflammation, Chronic Active                     3 (6%)       4 (8%)       1 (2%)       1 (2%)                                
      Necrosis                                                                                1 (2%)                                
   Seminal Vesicle                                    (50)         (50)         (49)         (49)                                   
      Inflammation, Chronic Active                                               1 (2%)                                             
      Necrosis                                                                                1 (2%)                                
   Testes                                             (50)         (50)         (50)         (50)                                   
      Atrophy                                          2 (4%)       4 (8%)       5 (10%)                                            
      Artery, Inflammation, Chronic Active             1 (2%)       1 (2%)       2 (4%)       3 (6%)                                
      Interstitial Cell, Hyperplasia                  13 (26%)     10 (20%)      6 (12%)     10 (20%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (48)         (50)                                   
      Necrosis                                                      1 (2%)                                                          
   Lymph Node                                         (8)          (9)          (9)          (9)                                    
      Iliac, Ectasia                                                                          1 (11%)                               
      Iliac, Hemorrhage                                                                       1 (11%)                               
      Pancreatic, Ectasia                                                        1 (11%)                                            
      Renal, Hemorrhage                                                          1 (11%)                                            
   Lymph Node, Bronchial                              (45)         (30)         (41)         (49)                                   
      Inflammation, Suppurative                                                  1 (2%)                                             
   Lymph Node, Mandibular                             (46)         (47)         (47)         (49)                                   
      Infiltration Cellular, Plasma Cell                                                      1 (2%)                                
   Lymph Node, Mediastinal                            (47)         (46)         (44)         (49)                                   
      Hemorrhage                                                    1 (2%)                    1 (2%)                                
   Spleen                                             (50)         (50)         (49)         (50)                                   
      Accessory Spleen                                 1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Depletion Cellular                                                         1 (2%)                                             
      Fibrosis                                        16 (32%)     16 (32%)     12 (24%)     13 (26%)                               
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       1 (2%)                                             
      Hyperplasia, Focal                                                                      1 (2%)                                
      Necrosis                                         2 (4%)                    1 (2%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (30)         (34)         (36)         (38)                                   
      Galactocele                                      2 (7%)       1 (3%)                    1 (3%)                                
      Hyperplasia, Atypical                                                      1 (3%)                                             
   Skin                                               (50)         (48)         (50)         (50)                                   
      Cyst Epithelial Inclusion                        1 (2%)                                                                       
      Inflammation, Chronic                            3 (6%)       1 (2%)       1 (2%)       1 (2%)                                
      Inflammation, Chronic Active                     1 (2%)       2 (4%)                    3 (6%)                                
      Subcutaneous Tissue, Edema                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Fibrous Osteodystrophy                                                     2 (4%)                                             
      Hyperostosis                                     2 (4%)       2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Developmental Malformation                                    1 (2%)                                                          
      Gliosis                                          1 (2%)       1 (2%)       1 (2%)                                             
      Mineralization                                                1 (2%)                                                          
      Necrosis                                         2 (4%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (49)         (48)         (50)                                   
      Epiglottis, Metaplasia, Squamous                             10 (20%)     37 (77%)     50 (100%)                              
   Lung                                               (50)         (50)         (48)         (50)                                   
      Cyst                                                                                    1 (2%)                                
      Foreign Body                                                                            1 (2%)                                
      Hemorrhage                                       1 (2%)                                                                       
      Hyperplasia, Atypical                                                      1 (2%)       1 (2%)                                
      Infiltration Cellular, Histiocyte                             1 (2%)       1 (2%)       1 (2%)                                
      Inflammation, Suppurative                                                               1 (2%)                                
      Metaplasia, Squamous                                          1 (2%)       4 (8%)       2 (4%)                                
      Mineralization                                                                          1 (2%)                                
      Proteinosis                                                  16 (32%)     40 (83%)     47 (94%)                               
      Thrombosis                                                    1 (2%)                    1 (2%)                                
      Alveolar Epithelium, Hyperplasia                 9 (18%)     20 (40%)     20 (42%)     23 (46%)                               
      Alveolar Epithelium, Hyperplasia, Atypical                    1 (2%)       2 (4%)       2 (4%)                                
      Alveolar Epithelium, Metaplasia                              50 (100%)    48 (100%)    49 (98%)                               
      Alveolus, Inflammation, Granulomatous            2 (4%)      50 (100%)    48 (100%)    50 (100%)                              
      Artery, Mediastinum, Mineralization                                                     1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 05156-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                    COBALT SULFATE HEPTAHYDRATE                                Date: 07/25/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:33:51  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      0.3          1.0          3.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Bronchiole, Inflammation, Chronic                                                       1 (2%)                                
      Interstitium, Fibrosis                           1 (2%)      50 (100%)    48 (100%)    49 (98%)                               
      Mediastinum, Inflammation, Suppurative                                     1 (2%)                                             
   Nose                                               (50)         (50)         (49)         (50)                                   
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Inflammation, Suppurative                        4 (8%)      15 (30%)      5 (10%)      6 (12%)                               
      Metaplasia, Squamous                             1 (2%)                                                                       
      Thrombosis                                      14 (28%)     18 (36%)      3 (6%)       9 (18%)                               
      Glands, Cyst                                     1 (2%)                                                                       
      Lateral Wall, Hyperplasia                        2 (4%)      14 (28%)     21 (43%)     20 (40%)                               
      Lateral Wall, Inflammation                                                              1 (2%)                                
      Lateral Wall, Metaplasia, Squamous               1 (2%)       3 (6%)       5 (10%)      8 (16%)                               
      Olfactory Epithelium, Atrophy                    8 (16%)     24 (48%)     42 (86%)     48 (96%)                               
      Olfactory Epithelium, Metaplasia                 5 (10%)      1 (2%)       5 (10%)     30 (60%)                               
      Respiratory Epithelium, Hyperplasia, Focal       6 (12%)      1 (2%)       3 (6%)       2 (4%)                                
      Respiratory Epithelium, Inflammation             4 (8%)                                 1 (2%)                                
      Respiratory Epithelium, Metaplasia, Squamous     1 (2%)                                 1 (2%)                                
   Trachea                                            (50)         (50)         (48)         (50)                                   
      Mineralization                                                                          1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (5)                       (1)          (1)                                    
      Cataract                                         5 (100%)                  1 (100%)     1 (100%)                              
      Retina, Atrophy                                  5 (100%)                  1 (100%)     1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (48)         (50)                                   
      Cyst                                             1 (2%)                                 1 (2%)                                
      Hydronephrosis                                                1 (2%)                    1 (2%)                                
      Infarct                                          4 (8%)       1 (2%)       1 (2%)       3 (6%)                                
      Nephropathy                                     49 (98%)     49 (98%)     48 (100%)    50 (100%)                              
      Thrombosis                                                                 1 (2%)                                             
      Papilla, Necrosis                                                                       1 (2%)                                
      Renal Tubule, Hyperplasia                        2 (4%)       4 (8%)       2 (4%)       2 (4%)                                
   Urinary Bladder                                    (50)         (50)         (48)         (50)                                   
      Necrosis                                                                                1 (2%)                                
      Transitional Epithelium, Hyperplasia                                                    1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
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