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TDMS Study 88007-06 Pathology Tables

NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99
Route: DOSED WATER                                                                                                Time: 09:34:16

                                                      2 YEAR CHRONIC MICE




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  7632-00-0

       Lock Date:  03/20/98

       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: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 


  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 1            7            2            4                                     
    Natural Death                                      9            9           11            5                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                40           34           37           41                                     

  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (48)         (50)         (50)         (49)                                   
      Cyst                                             1 (2%)       1 (2%)                                                          
      Infiltration Cellular, Mononuclear Cell                       3 (6%)       1 (2%)       4 (8%)                                
      Epithelium, Cytoplasmic Alteration                            1 (2%)                                                          
      Epithelium, Hyperplasia                                       1 (2%)                                                          
   Intestine Small, Duodenum                          (50)         (48)         (50)         (49)                                   
      Epithelium, Inflammation, Chronic Active         1 (2%)                                                                       
      Epithelium, Ulcer                                1 (2%)                                                                       
   Intestine Small, Jejunum                           (50)         (50)         (50)         (50)                                   
      Necrosis                                         1 (2%)                                                                       
      Peyer's Patch, Hyperplasia, Lymphoid                                                    1 (2%)                                
   Intestine Small, Ileum                             (49)         (49)         (50)         (50)                                   
      Inflammation, Chronic Active                                                            1 (2%)                                
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                                                             2 (4%)                                
      Basophilic Focus                                 3 (6%)       4 (8%)       3 (6%)       1 (2%)                                
      Clear Cell Focus                                 2 (4%)       3 (6%)       3 (6%)       2 (4%)                                
      Congestion                                                                              1 (2%)                                
      Eosinophilic Focus                               7 (14%)      3 (6%)       4 (8%)       5 (10%)                               
      Hematopoietic Cell Proliferation                 2 (4%)       5 (10%)      3 (6%)       4 (8%)                                
      Hemorrhage                                       1 (2%)                                                                       
      Infiltration Cellular, Mononuclear Cell         30 (60%)     32 (64%)     29 (58%)     35 (70%)                               
      Inflammation, Chronic Active                    36 (72%)     35 (70%)     30 (60%)     35 (70%)                               
      Mineralization                                   1 (2%)       1 (2%)       1 (2%)                                             
      Mixed Cell Focus                                 3 (6%)       1 (2%)                                                          
      Necrosis                                         5 (10%)      4 (8%)       3 (6%)       2 (4%)                                
      Pigmentation                                    12 (24%)     17 (34%)     16 (32%)     18 (36%)                               
      Thrombosis                                                    1 (2%)                                                          
      Vacuolization Cytoplasmic                       10 (20%)     17 (34%)     12 (24%)     13 (26%)                               
      Bile Duct, Cyst                                                            1 (2%)                                             
      Bile Duct, Hyperplasia                           1 (2%)       1 (2%)                    1 (2%)                                
      Centrilobular, Necrosis                                                                 2 (4%)                                
      Centrilobular, Vacuolization Cytoplasmic                                                1 (2%)                                
      Hepatocyte, Centrilobular, Hypertrophy           1 (2%)                                                                       

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
   Mesentery                                          (14)         (19)         (17)         (13)                                   
      Congestion                                                    1 (5%)                                                          
      Hemorrhage                                                                 1 (6%)                                             
      Infiltration Cellular, Mononuclear Cell                                                 1 (8%)                                
      Inflammation, Chronic Active                                  1 (5%)                                                          
      Inflammation, Granulomatous                      1 (7%)                                                                       
      Pigmentation, Hemosiderin                                                  1 (6%)                                             
      Thrombosis                                                    1 (5%)                                                          
      Artery, Inflammation, Chronic Active                                                    1 (8%)                                
      Fat, Necrosis                                   10 (71%)      7 (37%)     10 (59%)     11 (85%)                               
   Oral Mucosa                                        (1)                       (2)          (3)                                    
      Gingival, Foreign Body                           1 (100%)                  2 (100%)     3 (100%)                              
      Gingival, Inflammation, Chronic Active           1 (100%)                  2 (100%)     2 (67%)                               
   Pancreas                                           (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Mononuclear Cell         14 (28%)     10 (20%)      7 (14%)     13 (26%)                               
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Acinus, Atrophy                                  1 (2%)                                 1 (2%)                                
      Acinus, Hyperplasia                                                        1 (2%)                                             
      Acinus, Hypertrophy                                                                     1 (2%)                                
      Artery, Inflammation, Chronic Active                                       1 (2%)       1 (2%)                                
      Duct, Cyst                                       1 (2%)       1 (2%)                                                          
   Salivary Glands                                    (49)         (49)         (48)         (50)                                   
      Atrophy                                                                                 2 (4%)                                
      Infiltration Cellular, Mononuclear Cell         34 (69%)     36 (73%)     40 (83%)     35 (70%)                               
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Mononuclear Cell                       1 (2%)                                                          
      Ulcer                                            1 (2%)       2 (4%)       2 (4%)                                             
      Epithelium, Hyperkeratosis                                                              1 (2%)                                
      Epithelium, Hyperplasia                          2 (4%)       3 (6%)       3 (6%)       6 (12%)                               
      Epithelium, Inflammation, Chronic Active         2 (4%)       3 (6%)       3 (6%)       1 (2%)                                
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
      Mineralization                                   1 (2%)                                                                       
      Epithelium, Hyperplasia                                                    1 (2%)       1 (2%)                                
      Epithelium, Necrosis                                                       1 (2%)                                             
      Glands, Ectasia                                 19 (38%)     16 (32%)     10 (20%)     21 (42%)                               
      Glands, Necrosis                                                           1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Mononuclear Cell                                    1 (2%)                                             
      Aorta, Inflammation, Chronic Active                                                     1 (2%)                                
      Aorta, Mineralization                            2 (4%)                                                                       
      Pulmonary Artery, Mineralization                 1 (2%)                                                                       
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                                1 (2%)                                                          

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
CARDIOVASCULAR SYSTEM - CONT                                                                                                        
      Infiltration Cellular, Mononuclear Cell          1 (2%)                                                                       
      Inflammation, Chronic Active                                  1 (2%)       1 (2%)                                             
      Mineralization                                   1 (2%)       2 (4%)                    1 (2%)                                
      Artery, Inflammation, Chronic Active                                                    1 (2%)                                
      Artery, Mineralization                                        1 (2%)                                                          
      Valve, Inflammation, Chronic Active              2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (49)         (50)                                   
      Accessory Adrenal Cortical Nodule                1 (2%)       2 (4%)       1 (2%)       1 (2%)                                
      Degeneration, Fatty                                                        1 (2%)       2 (4%)                                
      Hematopoietic Cell Proliferation                 1 (2%)       2 (4%)                    2 (4%)                                
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Capsule, Hyperplasia                            49 (98%)     50 (100%)    49 (100%)    49 (98%)                               
      Zona Fasciculata, Hyperplasia                                              1 (2%)       1 (2%)                                
      Zona Fasciculata, Hypertrophy                    1 (2%)       1 (2%)                                                          
      Zona Glomerulosa, Hyperplasia                                 1 (2%)                    1 (2%)                                
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Hyperplasia                                     45 (90%)     44 (88%)     40 (80%)     42 (84%)                               
      Pigmentation                                                               1 (2%)                                             
   Parathyroid Gland                                  (33)         (31)         (31)         (37)                                   
      Cyst                                                                       1 (3%)                                             
   Pituitary Gland                                    (48)         (47)         (43)         (48)                                   
      Pars Distalis, Angiectasis                       1 (2%)       3 (6%)                    3 (6%)                                
      Pars Distalis, Cyst                                                        2 (5%)       2 (4%)                                
      Pars Distalis, Hyperplasia                       2 (4%)       3 (6%)       4 (9%)       6 (13%)                               
   Thyroid Gland                                      (49)         (49)         (48)         (49)                                   
      Inflammation, Chronic Active                     2 (4%)       1 (2%)                    1 (2%)                                
      Follicle, Cyst                                                2 (4%)                    1 (2%)                                
      Follicular Cell, Hyperplasia                                               1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                                      (1)                       (1)                                    
      Inflammation, Granulomatous                                                             1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (49)         (50)         (48)                                   
      Infiltration Cellular, Mononuclear Cell          7 (14%)      4 (8%)      13 (26%)      3 (6%)                                
      Inflammation, Chronic Active                     1 (2%)                                 1 (2%)                                
      Inflammation, Suppurative                                     2 (4%)       2 (4%)                                             
      Duct, Cyst                                       1 (2%)                                                                       

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
   Ovary                                              (47)         (49)         (50)         (49)                                   
      Angiectasis                                                                             1 (2%)                                
      Cyst                                             6 (13%)      9 (18%)      9 (18%)      7 (14%)                               
      Hemorrhage                                       2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
      Hyperplasia, Adenomatous                                      1 (2%)                                                          
      Mineralization                                   3 (6%)                                 1 (2%)                                
      Pigmentation                                                                            1 (2%)                                
      Thrombosis                                       2 (4%)                    1 (2%)       1 (2%)                                
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Hemorrhage                                                    1 (2%)                                                          
      Hydrometra                                      32 (64%)     31 (62%)     33 (66%)     37 (74%)                               
      Infiltration Cellular, Mononuclear Cell          2 (4%)                                                                       
      Inflammation, Suppurative                        1 (2%)                    2 (4%)                                             
      Endometrium, Hyperplasia, Cystic                13 (26%)     10 (20%)     16 (32%)     18 (36%)                               
      Submucosa, Hyperplasia, Stromal                                            1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Atrophy                                                                                 2 (4%)                                
      Hyperplasia                                                                             1 (2%)                                
      Myelofibrosis                                                              2 (4%)                                             
      Myeloid Cell, Hyperplasia                        2 (4%)       3 (6%)       1 (2%)       3 (6%)                                
   Lymph Node                                         (7)          (7)          (8)          (4)                                    
      Inflammation, Granulomatous                                                             1 (25%)                               
      Inguinal, Hyperplasia, Lymphoid                                            1 (13%)                                            
      Lumbar, Hyperplasia, Lymphoid                                                           1 (25%)                               
      Mediastinal, Hematopoietic Cell Proliferation                                           1 (25%)                               
      Mediastinal, Hyperplasia, Lymphoid                                         3 (38%)      1 (25%)                               
      Mediastinal, Pigmentation, Hemosiderin                        1 (14%)                                                         
      Renal, Ectasia                                   1 (14%)                   1 (13%)                                            
      Renal, Hemorrhage                                1 (14%)                   1 (13%)                                            
   Lymph Node, Mandibular                             (47)         (46)         (48)         (48)                                   
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hyperplasia, Lymphoid                            1 (2%)                    5 (10%)      5 (10%)                               
      Hyperplasia, Plasma Cell                                      1 (2%)       1 (2%)                                             
   Lymph Node, Mesenteric                             (50)         (49)         (47)         (49)                                   
      Ectasia                                          1 (2%)       1 (2%)       2 (4%)                                             
      Fibrosis                                                                   1 (2%)                                             
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hyperplasia, Lymphoid                                         1 (2%)       2 (4%)                                             
      Inflammation, Granulomatous                                                             1 (2%)                                
   Spleen                                             (49)         (50)         (50)         (50)                                   
      Hematopoietic Cell Proliferation                37 (76%)     39 (78%)     35 (70%)     39 (78%)                               
      Hyperplasia, Lymphoid                            4 (8%)       3 (6%)       4 (8%)       1 (2%)                                
      Metaplasia, Osseous                                           1 (2%)                                                          

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Capsule, Inflammation, Chronic Active                                                   1 (2%)                                
   Thymus                                             (46)         (47)         (44)         (46)                                   
      Cyst                                            10 (22%)     12 (26%)     17 (39%)     16 (35%)                               
      Ectopic Parathyroid Gland                        1 (2%)       5 (11%)      3 (7%)       2 (4%)                                
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (49)         (50)         (49)         (50)                                   
      Hyperplasia, Cystic                              1 (2%)       3 (6%)                    1 (2%)                                
   Skin                                               (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic Active                     1 (2%)       3 (6%)       2 (4%)                                             
      Ulcer                                            1 (2%)       1 (2%)       1 (2%)                                             
      Epidermis, Hyperplasia                                        1 (2%)       1 (2%)                                             
      Subcutaneous Tissue, Fibrosis                    2 (4%)                                                                       
      Subcutaneous Tissue, Infiltration Cellular,                                                                                   
           Mononuclear Cell                                                                   2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Periosteum, Synovial Tissue, Inflammation,                                                                                    
           Chronic Active                                                                     1 (2%)                                
   Skeletal Muscle                                    (3)          (2)          (1)          (3)                                    
      Artery, Inflammation, Chronic Active                                                    1 (33%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (49)         (50)                                   
      Degeneration                                     1 (2%)                                                                       
      Hemorrhage                                       1 (2%)       1 (2%)                                                          
   Peripheral Nerve                                                                          (2)                                    
      Sciatic, Inflammation, Chronic Active                                                   1 (50%)                               
   Spinal Cord                                                                               (2)                                    
      Demyelination                                                                           2 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Hemorrhage                                                                 1 (2%)                                             
      Infiltration Cellular, Mononuclear Cell          1 (2%)       2 (4%)                    1 (2%)                                
      Inflammation, Chronic Active                     2 (4%)       3 (6%)       2 (4%)                                             
      Metaplasia, Osseous                                                                     1 (2%)                                

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Mineralization                                                1 (2%)       1 (2%)                                             
      Alveolar Epithelium, Hyperplasia                              1 (2%)       4 (8%)       3 (6%)                                
      Alveolus, Infiltration Cellular, Histiocyte                   3 (6%)       2 (4%)       2 (4%)                                
      Bronchus, Mineralization                         1 (2%)                                                                       
      Interstitium, Inflammation, Chronic Active                                              1 (2%)                                
      Vein, Mineralization                             1 (2%)       1 (2%)       1 (2%)                                             
   Nose                                               (50)         (49)         (50)         (50)                                   
      Foreign Body                                                               1 (2%)                                             
      Inflammation, Chronic Active                                               1 (2%)                                             
      Nasolacrimal Duct, Inflammation, Suppurative                  1 (2%)       1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                                          (1)                                                 
      Cataract                                                                   1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Accumulation, Hyaline Droplet                                 1 (2%)                                                          
      Infarct                                          2 (4%)       4 (8%)       3 (6%)       6 (12%)                               
      Infiltration Cellular, Mononuclear Cell         35 (70%)     37 (74%)     34 (68%)     40 (80%)                               
      Infiltration Cellular, Plasma Cell                                                      1 (2%)                                
      Inflammation, Suppurative                        1 (2%)                                                                       
      Mineralization                                   5 (10%)      8 (16%)      6 (12%)      4 (8%)                                
      Nephropathy                                     20 (40%)     17 (34%)     13 (26%)     20 (40%)                               
      Cortex, Cyst                                                                            1 (2%)                                
      Vein, Inflammation, Chronic Active                                                      1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Mononuclear Cell         25 (50%)     29 (58%)     24 (48%)     25 (50%)                               
      Inflammation, Chronic Active                     1 (2%)                                 1 (2%)                                
      Mineralization                                   1 (2%)                                                                       
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 


  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 3            2            3            1                                     
    Natural Death                                      8            3            5           10                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                39           45           42           39                                     

  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (50)         (50)         (49)         (49)                                   
      Cyst                                             1 (2%)                                                                       
   Intestine Small, Duodenum                          (49)         (50)         (48)         (49)                                   
      Ectasia                                                       2 (4%)                    2 (4%)                                
   Intestine Small, Jejunum                           (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic Active                                               1 (2%)                                             
      Intussusception                                                            1 (2%)                                             
      Peyer's Patch, Hyperplasia, Lymphoid                          2 (4%)                                                          
      Peyer's Patch, Inflammation, Granulomatous                                              1 (2%)                                
   Intestine Small, Ileum                             (50)         (49)         (50)         (50)                                   
      Parasite Metazoan                                                          1 (2%)                                             
   Liver                                              (50)         (50)         (50)         (50)                                   
      Basophilic Focus                                 3 (6%)       3 (6%)                    1 (2%)                                
      Clear Cell Focus                                 4 (8%)       6 (12%)     10 (20%)      7 (14%)                               
      Eosinophilic Focus                              12 (24%)     14 (28%)     14 (28%)      7 (14%)                               
      Fibrosis                                         1 (2%)                                                                       
      Hematopoietic Cell Proliferation                                           1 (2%)       1 (2%)                                
      Infarct                                          2 (4%)                                                                       
      Infiltration Cellular, Mononuclear Cell          2 (4%)                    3 (6%)       1 (2%)                                
      Inflammation, Chronic Active                    25 (50%)     25 (50%)     31 (62%)     19 (38%)                               
      Mineralization                                   1 (2%)       1 (2%)                    2 (4%)                                
      Mixed Cell Focus                                 6 (12%)      2 (4%)       7 (14%)      9 (18%)                               
      Necrosis                                        12 (24%)      4 (8%)       6 (12%)      2 (4%)                                
      Pigmentation                                     2 (4%)                    2 (4%)       1 (2%)                                
      Vacuolization Cytoplasmic                        3 (6%)                    3 (6%)       1 (2%)                                
      Bile Duct, Cyst                                                                         1 (2%)                                
      Bile Duct, Hyperplasia                           1 (2%)       1 (2%)       1 (2%)       2 (4%)                                
      Hepatocyte, Karyomegaly                                                    1 (2%)                                             
   Mesentery                                          (7)          (6)          (7)          (5)                                    
      Infiltration Cellular, Mononuclear Cell          2 (29%)                                                                      
      Inflammation, Granulomatous                      2 (29%)                   2 (29%)                                            
      Mineralization                                   1 (14%)      1 (17%)                                                         
      Pigmentation                                                  1 (17%)      1 (14%)                                            
      Artery, Inflammation, Chronic Active                          1 (17%)                                                         

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Fat, Necrosis                                    4 (57%)      4 (67%)      3 (43%)      2 (40%)                               
   Oral Mucosa                                        (26)         (27)         (17)         (19)                                   
      Gingival, Foreign Body                          26 (100%)    27 (100%)    17 (100%)    19 (100%)                              
      Gingival, Inflammation, Chronic Active          21 (81%)     22 (81%)     14 (82%)     11 (58%)                               
   Pancreas                                           (49)         (50)         (50)         (50)                                   
      Fibrosis                                         1 (2%)                                                                       
      Infiltration Cellular, Mononuclear Cell          2 (4%)       2 (4%)       3 (6%)       2 (4%)                                
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Acinus, Atrophy                                  1 (2%)       1 (2%)                                                          
      Acinus, Hypertrophy                                                        1 (2%)                                             
      Artery, Inflammation, Chronic Active                          1 (2%)                                                          
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Atrophy                                          1 (2%)                                                                       
      Infiltration Cellular, Mononuclear Cell         27 (54%)     28 (56%)     33 (66%)     32 (64%)                               
      Mineralization                                   1 (2%)                                 1 (2%)                                
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Ulcer                                            3 (6%)                    1 (2%)       1 (2%)                                
      Epithelium, Hyperplasia                          6 (12%)      1 (2%)       2 (4%)       3 (6%)                                
      Epithelium, Inflammation, Chronic Active         2 (4%)                    2 (4%)       1 (2%)                                
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
      Mineralization                                                             1 (2%)                                             
      Epithelium, Erosion                                                        1 (2%)                                             
      Epithelium, Hyperplasia                                                    2 (4%)      10 (20%)                               
      Epithelium, Necrosis                                                                    1 (2%)                                
      Glands, Ectasia                                 12 (24%)     18 (36%)     16 (32%)     14 (28%)                               
   Tooth                                              (5)          (5)          (4)          (1)                                    
      Malformation                                     5 (100%)     4 (80%)      3 (75%)      1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (50)         (50)         (50)         (50)                                   
      Aorta, Inflammation, Chronic Active                           1 (2%)                                                          
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                                                          1 (2%)                                
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Mineralization                                   3 (6%)                    1 (2%)                                             
      Artery, Inflammation, Chronic Active                          2 (4%)                                                          
      Atrium, Thrombosis                               1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Accessory Adrenal Cortical Nodule                2 (4%)                    6 (12%)      4 (8%)                                
      Degeneration, Fatty                              1 (2%)                    1 (2%)                                             
      Pigmentation                                                  1 (2%)                                                          

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Capsule, Hyperplasia                            46 (92%)     42 (84%)     40 (80%)     40 (80%)                               
      Zona Fasciculata, Hyperplasia                                 1 (2%)                    1 (2%)                                
      Zona Fasciculata, Hypertrophy                   18 (36%)     24 (48%)     14 (28%)     21 (42%)                               
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Hyperplasia                                                   1 (2%)                                                          
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Hyperplasia                                     46 (92%)     47 (94%)     49 (98%)     44 (88%)                               
   Parathyroid Gland                                  (36)         (48)         (38)         (41)                                   
      Cyst                                                                       1 (3%)                                             
   Pituitary Gland                                    (49)         (49)         (47)         (47)                                   
      Pars Distalis, Cyst                              3 (6%)       2 (4%)       2 (4%)       4 (9%)                                
      Pars Distalis, Hyperplasia                                    1 (2%)                                                          
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Follicle, Cyst                                   4 (8%)       1 (2%)       1 (2%)       2 (4%)                                
      Follicular Cell, Hyperplasia                                  1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                               (1)                                                              
      Inflammation, Chronic Active                                  1 (100%)                                                        
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm                                  1 (2%)       1 (2%)                    1 (2%)                                
      Infiltration Cellular, Mononuclear Cell         21 (42%)     22 (44%)     25 (50%)     25 (50%)                               
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Inflammation, Chronic Active                                               1 (2%)                                             
   Preputial Gland                                    (50)         (50)         (49)         (50)                                   
      Atrophy                                          1 (2%)                    1 (2%)                                             
      Infiltration Cellular, Mononuclear Cell         27 (54%)     28 (56%)     29 (59%)     25 (50%)                               
      Inflammation, Chronic Active                     7 (14%)      8 (16%)      4 (8%)       4 (8%)                                
      Inflammation, Suppurative                                                  2 (4%)                                             
      Duct, Cyst                                      33 (66%)     32 (64%)     33 (67%)     39 (78%)                               
   Prostate                                           (50)         (50)         (49)         (50)                                   
      Infiltration Cellular, Mononuclear Cell         15 (30%)     22 (44%)     29 (59%)     28 (56%)                               
      Inflammation, Chronic Active                     1 (2%)       2 (4%)       3 (6%)                                             
      Inflammation, Suppurative                        1 (2%)                    1 (2%)                                             
      Artery, Inflammation, Chronic Active                          2 (4%)                                                          
   Seminal Vesicle                                    (50)         (50)         (50)         (50)                                   
      Congestion                                                                              1 (2%)                                
      Dilatation                                       2 (4%)       2 (4%)                                                          
      Infiltration Cellular, Mononuclear Cell                       1 (2%)       1 (2%)       1 (2%)                                

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Inflammation, Chronic Active                     2 (4%)                                                                       
      Inflammation, Suppurative                                                  1 (2%)                                             
      Bilateral, Dilatation                            1 (2%)       1 (2%)       1 (2%)                                             
   Testes                                             (50)         (50)         (50)         (50)                                   
      Mineralization                                                                          2 (4%)                                
      Germinal Epithelium, Atrophy                                  1 (2%)                    1 (2%)                                
      Germinal Epithelium, Necrosis                                              1 (2%)                                             
      Interstitial Cell, Hyperplasia                                             2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (49)         (50)                                   
      Hemorrhage                                                                 1 (2%)                                             
      Thrombosis                                                                 1 (2%)                                             
      Myeloid Cell, Hyperplasia                                                  1 (2%)       2 (4%)                                
   Lymph Node                                         (1)          (1)          (3)          (5)                                    
      Lumbar, Hyperplasia, Plasma Cell                                           1 (33%)                                            
      Mediastinal, Hemorrhage                                                                 1 (20%)                               
      Mediastinal, Inflammation, Granulomatous                                                1 (20%)                               
      Renal, Hyperplasia, Lymphoid                                  1 (100%)                                                        
      Renal, Hyperplasia, Plasma Cell                                            1 (33%)                                            
   Lymph Node, Mandibular                             (47)         (50)         (47)         (48)                                   
      Hyperplasia, Lymphoid                            2 (4%)       1 (2%)       1 (2%)                                             
   Lymph Node, Mesenteric                             (49)         (49)         (48)         (49)                                   
      Ectasia                                                       1 (2%)                                                          
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hyperplasia, Plasma Cell                                      2 (4%)       1 (2%)                                             
      Hyperplasia, Lymphocyte                          1 (2%)                    1 (2%)                                             
      Infiltration Cellular, Eosinophil                             1 (2%)                                                          
      Inflammation, Chronic Active                                                            1 (2%)                                
      Inflammation, Granulomatous                                                1 (2%)       2 (4%)                                
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Hematopoietic Cell Proliferation                22 (44%)     11 (22%)     14 (28%)     20 (40%)                               
      Hyperplasia, Lymphoid                            1 (2%)                    1 (2%)                                             
   Thymus                                             (37)         (39)         (38)         (42)                                   
      Cyst                                             9 (24%)     14 (36%)     16 (42%)      9 (21%)                               
      Hemorrhage                                       1 (3%)                                                                       
      Inflammation, Granulomatous                      1 (3%)                                                                       
      Necrosis                                         1 (3%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                        1 (2%)                                                                       
      Inflammation, Chronic Active                     4 (8%)       1 (2%)       1 (2%)       2 (4%)                                
      Ulcer                                            3 (6%)       1 (2%)       1 (2%)       2 (4%)                                
      Epidermis, Hyperplasia                           2 (4%)       1 (2%)       1 (2%)                                             
      Subcutaneous Tissue, Infiltration Cellular,                                                                                   
           Mononuclear Cell                                                      1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (49)         (50)                                   
      Cranium, Hyperostosis                            1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Neuron, Necrosis                                 2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Hemorrhage                                                                              1 (2%)                                
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Chronic Active                     1 (2%)       1 (2%)       1 (2%)                                             
      Mineralization                                   4 (8%)                    3 (6%)                                             
      Necrosis                                                                                2 (4%)                                
      Alveolar Epithelium, Hyperplasia                 3 (6%)       2 (4%)       6 (12%)      9 (18%)                               
      Alveolus, Infiltration Cellular, Histiocyte      3 (6%)       1 (2%)       2 (4%)       3 (6%)                                
      Interstitium, Inflammation, Chronic Active                                 1 (2%)                                             
      Mediastinum, Inflammation, Chronic Active                     1 (2%)                                                          
      Mediastinum, Inflammation, Suppurative                                     1 (2%)                                             
      Mediastinum, Pigmentation                                     1 (2%)                                                          
   Nose                                               (50)         (50)         (49)         (50)                                   
      Foreign Body                                     2 (4%)       1 (2%)       3 (6%)       1 (2%)                                
      Inflammation, Chronic Active                     1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
      Inflammation, Suppurative                        1 (2%)                    1 (2%)                                             
      Nasolacrimal Duct, Inflammation, Suppurative                  1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 88007-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           SODIUM NITRITE                                      Date: 05/13/99  
Route: DOSED WATER                                                                                                Time: 09:34:16  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0.0%         0.075%       0.15%        0.30%                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)                                                                           
      Atrophy                                          1 (100%)                                                                     
   Harderian Gland                                    (5)          (4)          (6)          (1)                                    
      Hyperplasia                                                   1 (25%)                                                         
      Inflammation, Chronic                                         1 (25%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Hydronephrosis                                                             1 (2%)       1 (2%)                                
      Infarct                                         11 (22%)     10 (20%)      9 (18%)     13 (26%)                               
      Infiltration Cellular, Mononuclear Cell         42 (84%)     41 (82%)     41 (82%)     45 (90%)                               
      Infiltration Cellular, Plasma Cell                                         1 (2%)                                             
      Inflammation, Chronic Active                     2 (4%)       1 (2%)                    1 (2%)                                
      Inflammation, Suppurative                        1 (2%)                    1 (2%)                                             
      Metaplasia, Osseous                              2 (4%)       3 (6%)                                                          
      Mineralization                                  48 (96%)     50 (100%)    48 (96%)     46 (92%)                               
      Necrosis                                         1 (2%)       1 (2%)                                                          
      Nephropathy                                     44 (88%)     49 (98%)     45 (90%)     42 (84%)                               
      Pigmentation                                     1 (2%)                                                                       
      Artery, Inflammation, Chronic Active                          2 (4%)       1 (2%)                                             
      Cortex, Cyst                                     5 (10%)      9 (18%)      6 (12%)      4 (8%)                                
      Renal Tubule, Hypertrophy, Focal                                                        1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (49)                                   
      Infiltration Cellular, Mononuclear Cell          6 (12%)      7 (14%)     16 (32%)     10 (20%)                               
      Inflammation, Suppurative                                     1 (2%)                                                          
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------