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TDMS Study 88007-06 Pathology Tables

NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: Battelle Columbus                                       SODIUM NITRITE                                    DATE: 05/13/99       
EXPERIMENT: 88007 TEST: 06                                                                                     TIME: 09:40:55       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                   PAGE:       1        
CONT: NO1-ES-55384                              ROUTE: DOSED WATER                                             NTP C#: C88007       
PATHOLOGIST: TOFT, JOHN                                                                                        CAS: 7632-00-0       
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
                                                        2 YEAR CHRONIC MICE                                                         
                                                                                                                                    

               REASONS FOR REMOVAL:    ALL                                                                                          
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
               REMOVAL DATE RANGE:     ALL                                                                                          
                                                                                                                                    
               TREATMENT GROUPS:       INCLUDE ALL                                                                                  
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08
LAB: Battelle Columbus                                       SODIUM NITRITE                                    DATE: 05/13/99

EXPERIMENT: 88007 TEST: 06                                                                                     TIME: 09:40:55
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE
CONT: NO1-ES-55384                              ROUTE: DOSED WATER                                             NTP C#: C88007
PATHOLOGIST: TOFT, JOHN                                                                                        CAS: 7632-00-0

Mice(B6C3F1)
-----------------------------
FOR ALL DOSES THE TUMOR RATES IN THE FOLLOWING TISSUES/ORGANS ARE
BASED ON NUMBER OF TISSUES EXAMINED.  IN OTHER TISSUES/ORGANS RATES
ARE BASED ON THE NUMBER OF ANIMALS NECROPSIED.
                                                 ---------------
                                                 Adrenal Medulla
                                                 Bone Marrow
                                                 Brain
                                                 Islets, Pancreatic
                                                 Kidney
                                                 Liver
                                                 Lung
                                                 Ovary
                                                 Pituitary Gland
                                                 Spleen
                                                 Testes
                                                 Thymus
                                                 Thyroid Gland
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08   
LAB: Battelle Columbus                                       SODIUM NITRITE                                    DATE: 05/13/99     
EXPERIMENT: 88007 TEST: 06                                                                                     TIME: 09:40:55     
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                                      
CONT: NO1-ES-55384                              ROUTE: DOSED WATER                                             NTP C#: C88007     
PATHOLOGIST: TOFT, JOHN                                                                                        CAS: 7632-00-0     



SUMMARY OF STATISTICALLY SIGNIFICANT (P<=.05) RESULTS
IN THE ANALYSIS OF                  SODIUM NITRITE
===============================================================

Male Mice
------------
Organ                                 Morphology
-----                                 ----------
Intestine Small: Jejunum               Carcinoma
Intestine Small: Site Unspecified      Carcinoma
Liver                                  Hepatoblastoma
                                       Hepatocellular Carcinoma or Hepatocellular Adenoma
                                       Hepatocellular Carcinoma, Hepatocellular Adenoma, or Hepatoblastoma
Lung                                   Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma
All Organs                             Malignant Tumors
===============================================================
Female Mice
------------
Organ                                  Morphology
-----                                  ----------
Lung                                   Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma
Skin                                   Fibrosarcoma
                                       Schwannoma Malignant
Stomach, Forestomach                   Squamous Cell Carcinoma
                                       Squamous Cell Carcinoma or Papilloma Squamous
All Organs                             Benign Tumors
                                       Malignant Tumors
                                       Malignant and Benign Tumors
===============================================================
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 1
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)        -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Bone Marrow                                                                                                                      |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    0/50 (0%)    0/49 (0%)    0/50 (0%)   |0/50 (0%)    1/50 (2%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     4.3%         0.0%         0.0%         0.0%        |0.0%         2.2%         0.0%         0.0%         |
|TERMINAL (d)       |     1/39 (3%)    0/45 (0%)    0/41 (0%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |     661          ---          ---          ---         |---          605          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.117N     P=0.222N     P=0.232N     P=0.245N    |P=0.568N     P=0.517      (e)          (e)          |
|POLY 3             |     P=0.114N     P=0.234N     P=0.239N     P=0.245N    |P=0.564N     P=0.502      (e)          (e)          |
|POLY 1.5           |     P=0.114N     P=0.236N     P=0.240N     P=0.242N    |P=0.565N     P=0.501      (e)          (e)          |
|POLY 6             |     P=0.114N     P=0.231N     P=0.239N     P=0.248N    |P=0.564N     P=0.499      (e)          (e)          |
|LOGISTIC REGRESSION|     P=0.111N     P=0.242N     P=0.254N     P=0.230N    |P=0.523N     P=0.441      (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.116N     P=0.247N     P=0.253N     P=0.247N    |P=0.567N     P=0.500      (e)          (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     4/50 (8%)    3/50 (6%)    4/50 (8%)    1/50 (2%)   |0/50 (0%)    1/50 (2%)    0/50 (0%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     8.5%         6.2%         8.4%         2.2%        |0.0%         2.2%         0.0%         4.3%         |
|TERMINAL (d)       |     2/39 (5%)    2/45 (4%)    4/42 (10%)   1/39 (3%)   |0/40 (0%)    1/34 (3%)    0/37 (0%)    2/41 (5%)    |
|FIRST INCIDENCE    |     661          612          727 (T)      727 (T)     |---          728 (T)      ---          728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.171N     P=0.446N     P=0.606N     P=0.188N    |P=0.157      P=0.468      (e)          P=0.244      |
|POLY 3             |     P=0.173N     P=0.488N     P=0.637N     P=0.190N    |P=0.142      P=0.500      (e)          P=0.241      |
|POLY 1.5           |     P=0.167N     P=0.494N     P=0.639N     P=0.186N    |P=0.141      P=0.500      (e)          P=0.239      |
|POLY 6             |     P=0.181N     P=0.478N     P=0.637N     P=0.195N    |P=0.145      P=0.496      (e)          P=0.244      |
|LOGISTIC REGRESSION|     P=0.159N     P=0.510N     P=0.635N     P=0.185N    |(e)          P=0.468      (e)          P=0.244      |
|COCH-ARM / FISHERS |     P=0.157N     P=0.500N     P=0.643N     P=0.181N    |P=0.140      P=0.500      (e)          P=0.247      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 2
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    2/50 (4%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    1/50 (2%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         4.2%         0.0%        |0.0%         0.0%         2.1%         0.0%         |
|TERMINAL (d)       |     0/39 (0%)    0/45 (0%)    2/42 (5%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    1/37 (3%)    0/41 (0%)    |
|FIRST INCIDENCE    |     ---          ---          727 (T)      ---         |---          ---          728 (T)      ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.588      (e)          P=0.255      (e)         |P=0.698      (e)          P=0.484      (e)          |
|POLY 3             |     P=0.574      (e)          P=0.241      (e)         |P=0.700      (e)          P=0.504      (e)          |
|POLY 1.5           |     P=0.582      (e)          P=0.240      (e)         |P=0.696      (e)          P=0.503      (e)          |
|POLY 6             |     P=0.564      (e)          P=0.242      (e)         |P=0.708      (e)          P=0.506      (e)          |
|LOGISTIC REGRESSION|     (e)          (e)          P=0.255      (e)         |(e)          (e)          P=0.484      (e)          |
|COCH-ARM / FISHERS |     P=0.595      (e)          P=0.247      (e)         |P=0.694      (e)          P=0.500      (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     4/50 (8%)    3/50 (6%)    5/50 (10%)   1/50 (2%)   |0/50 (0%)    1/50 (2%)    1/50 (2%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     8.5%         6.2%         10.5%        2.2%        |0.0%         2.2%         2.1%         4.3%         |
|TERMINAL (d)       |     2/39 (5%)    2/45 (4%)    5/42 (12%)   1/39 (3%)   |0/40 (0%)    1/34 (3%)    1/37 (3%)    2/41 (5%)    |
|FIRST INCIDENCE    |     661          612          727 (T)      727 (T)     |---          728 (T)      728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.194N     P=0.446N     P=0.540      P=0.188N    |P=0.173      P=0.468      P=0.484      P=0.244      |
|POLY 3             |     P=0.198N     P=0.488N     P=0.506      P=0.190N    |P=0.158      P=0.500      P=0.504      P=0.241      |
|POLY 1.5           |     P=0.190N     P=0.494N     P=0.504      P=0.186N    |P=0.156      P=0.500      P=0.503      P=0.239      |
|POLY 6             |     P=0.207N     P=0.478N     P=0.507      P=0.195N    |P=0.162      P=0.496      P=0.506      P=0.244      |
|LOGISTIC REGRESSION|     P=0.183N     P=0.510N     P=0.512      P=0.185N    |(e)          P=0.468      P=0.484      P=0.244      |
|COCH-ARM / FISHERS |     P=0.178N     P=0.500N     P=0.500      P=0.181N    |P=0.153      P=0.500      P=0.500      P=0.247      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 3
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Intestine Small: Duodenum                                                                                                        |
|     Polyp Adenomatous                                                                                                           |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    4/50 (8%)    3/50 (6%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     4.3%         8.4%         6.3%         0.0%        |0.0%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     2/39 (5%)    4/45 (9%)    3/42 (7%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |     727 (T)      727 (T)      727 (T)      ---         |---          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.141N     P=0.405      P=0.534      P=0.238N    |(e)          (e)          (e)          (e)          |
|POLY 3             |     P=0.146N     P=0.347      P=0.508      P=0.244N    |(e)          (e)          (e)          (e)          |
|POLY 1.5           |     P=0.142N     P=0.342      P=0.505      P=0.241N    |(e)          (e)          (e)          (e)          |
|POLY 6             |     P=0.150N     P=0.355      P=0.511      P=0.246N    |(e)          (e)          (e)          (e)          |
|LOGISTIC REGRESSION|     P=0.141N     P=0.405      P=0.534      (e)         |(e)          (e)          (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.137N     P=0.339      P=0.500      P=0.247N    |(e)          (e)          (e)          (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Intestine Small: Jejunum                                                                                                         |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     5/50 (10%)   1/50 (2%)    1/50 (2%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     10.6%        2.1%         2.1%         0.0%        |0.0%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     4/39 (10%)   1/45 (2%)    1/42 (2%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |     643          727 (T)      727 (T)      ---         |---          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.016N*    P=0.081N     P=0.092N     P=0.036N*   |(e)          (e)          (e)          (e)          |
|POLY 3             |     P=0.016N*    P=0.098N     P=0.099N     P=0.034N*   |(e)          (e)          (e)          (e)          |
|POLY 1.5           |     P=0.015N*    P=0.100N     P=0.100N     P=0.033N*   |(e)          (e)          (e)          (e)          |
|POLY 6             |     P=0.016N*    P=0.095N     P=0.098N     P=0.035N*   |(e)          (e)          (e)          (e)          |
|LOGISTIC REGRESSION|     P=0.016N*    P=0.102N     P=0.101N     P=0.035N*   |(e)          (e)          (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.016N*    P=0.102N     P=0.102N     P=0.028N*   |(e)          (e)          (e)          (e)          |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 4
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Intestine Small: Site Unspecified                                                                                                |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     5/50 (10%)   2/50 (4%)    1/50 (2%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     10.6%        4.2%         2.1%         0.0%        |0.0%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     4/39 (10%)   2/45 (4%)    1/42 (2%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |     643          727 (T)      727 (T)      ---         |---          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.014N*    P=0.173N     P=0.092N     P=0.036N*   |(e)          (e)          (e)          (e)          |
|POLY 3             |     P=0.014N*    P=0.211N     P=0.099N     P=0.034N*   |(e)          (e)          (e)          (e)          |
|POLY 1.5           |     P=0.014N*    P=0.214N     P=0.100N     P=0.033N*   |(e)          (e)          (e)          (e)          |
|POLY 6             |     P=0.015N*    P=0.206N     P=0.098N     P=0.035N*   |(e)          (e)          (e)          (e)          |
|LOGISTIC REGRESSION|     P=0.015N*    P=0.211N     P=0.101N     P=0.035N*   |(e)          (e)          (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.014N*    P=0.218N     P=0.102N     P=0.028N*   |(e)          (e)          (e)          (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Intestine Small: Site Unspecified                                                                                                |
|     Polyp Adenomatous                                                                                                           |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    4/50 (8%)    3/50 (6%)    1/50 (2%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     4.3%         8.4%         6.3%         2.2%        |0.0%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     2/39 (5%)    4/45 (9%)    3/42 (7%)    1/39 (3%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |     727 (T)      727 (T)      727 (T)      727 (T)     |---          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.305N     P=0.405      P=0.534      P=0.500N    |(e)          (e)          (e)          (e)          |
|POLY 3             |     P=0.307N     P=0.347      P=0.508      P=0.510N    |(e)          (e)          (e)          (e)          |
|POLY 1.5           |     P=0.301N     P=0.342      P=0.505      P=0.506N    |(e)          (e)          (e)          (e)          |
|POLY 6             |     P=0.313N     P=0.355      P=0.511      P=0.514N    |(e)          (e)          (e)          (e)          |
|LOGISTIC REGRESSION|     P=0.305N     P=0.405      P=0.534      P=0.500N    |(e)          (e)          (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.292N     P=0.339      P=0.500      P=0.500N    |(e)          (e)          (e)          (e)          |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 5
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Islets, Pancreatic                                                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     3/50 (6%)    2/50 (4%)    2/50 (4%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    3/50 (6%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     6.4%         4.2%         4.2%         0.0%        |0.0%         0.0%         6.4%         0.0%         |
|TERMINAL (d)       |     1/39 (3%)    2/45 (4%)    2/42 (5%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    2/37 (5%)    0/41 (0%)    |
|FIRST INCIDENCE    |     652          727 (T)      727 (T)      ---         |---          ---          716          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.092N     P=0.457N     P=0.480N     P=0.131N    |P=0.555      (e)          P=0.114      (e)          |
|POLY 3             |     P=0.093N     P=0.495N     P=0.497N     P=0.126N    |P=0.550      (e)          P=0.123      (e)          |
|POLY 1.5           |     P=0.090N     P=0.497N     P=0.497N     P=0.123N    |P=0.543      (e)          P=0.121      (e)          |
|POLY 6             |     P=0.096N     P=0.490N     P=0.497N     P=0.129N    |P=0.562      (e)          P=0.125      (e)          |
|LOGISTIC REGRESSION|     P=0.086N     P=0.505N     P=0.511N     P=0.111N    |P=0.556      (e)          P=0.125      (e)          |
|COCH-ARM / FISHERS |     P=0.086N     P=0.500N     P=0.500N     P=0.121N    |P=0.539      (e)          P=0.121      (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Islets, Pancreatic                                                                                                               |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     3/50 (6%)    3/50 (6%)    2/50 (4%)    0/50 (0%)   |0/50 (0%)    1/50 (2%)    3/50 (6%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     6.4%         6.3%         4.2%         0.0%        |0.0%         2.2%         6.4%         0.0%         |
|TERMINAL (d)       |     1/39 (3%)    3/45 (7%)    2/42 (5%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    2/37 (5%)    0/41 (0%)    |
|FIRST INCIDENCE    |     652          727 (T)      727 (T)      ---         |---          664          716          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.077N     P=0.613N     P=0.480N     P=0.131N    |P=0.609N     P=0.500      P=0.114      (e)          |
|POLY 3             |     P=0.078N     P=0.657N     P=0.497N     P=0.126N    |P=0.627N     P=0.501      P=0.123      (e)          |
|POLY 1.5           |     P=0.075N     P=0.659N     P=0.497N     P=0.123N    |P=0.631N     P=0.501      P=0.121      (e)          |
|POLY 6             |     P=0.081N     P=0.652N     P=0.497N     P=0.129N    |P=0.618N     P=0.498      P=0.125      (e)          |
|LOGISTIC REGRESSION|     P=0.073N     P=0.661      P=0.511N     P=0.111N    |P=0.632N     P=0.483      P=0.125      (e)          |
|COCH-ARM / FISHERS |     P=0.072N     P=0.661N     P=0.500N     P=0.121N    |P=0.634      P=0.500      P=0.121      (e)          |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 6
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    2/50 (4%)    1/50 (2%)    2/50 (4%)   |0/50 (0%)    0/50 (0%)    1/50 (2%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     4.3%         4.2%         2.1%         4.3%        |0.0%         0.0%         2.1%         0.0%         |
|TERMINAL (d)       |     1/39 (3%)    2/45 (4%)    0/42 (0%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    1/37 (3%)    0/41 (0%)    |
|FIRST INCIDENCE    |     705          727 (T)      664          549         |---          ---          728 (T)      ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.595N     P=0.646N     P=0.481N     P=0.683     |P=0.698      (e)          P=0.484      (e)          |
|POLY 3             |     P=0.582N     P=0.687N     P=0.493N     P=0.688     |P=0.700      (e)          P=0.504      (e)          |
|POLY 1.5           |     P=0.580N     P=0.690N     P=0.496N     P=0.690     |P=0.696      (e)          P=0.503      (e)          |
|POLY 6             |     P=0.583N     P=0.681N     P=0.490N     P=0.687     |P=0.708      (e)          P=0.506      (e)          |
|LOGISTIC REGRESSION|     P=0.538N     P=0.681N     P=0.516N     P=0.657N    |(e)          (e)          P=0.484      (e)          |
|COCH-ARM / FISHERS |     P=0.577N     P=0.691N     P=0.500N     P=0.691N    |P=0.694      (e)          P=0.500      (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatoblastoma                                                                                                              |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     5/50 (10%)   1/50 (2%)    2/50 (4%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     10.6%        2.1%         4.2%         0.0%        |0.0%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     3/39 (8%)    1/45 (2%)    2/42 (5%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |     617          727 (T)      727 (T)      ---         |---          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.027N*    P=0.085N     P=0.199N     P=0.039N*   |(e)          (e)          (e)          (e)          |
|POLY 3             |     P=0.027N*    P=0.099N     P=0.214N     P=0.034N*   |(e)          (e)          (e)          (e)          |
|POLY 1.5           |     P=0.026N*    P=0.101N     P=0.215N     P=0.033N*   |(e)          (e)          (e)          (e)          |
|POLY 6             |     P=0.028N*    P=0.097N     P=0.214N     P=0.036N*   |(e)          (e)          (e)          (e)          |
|LOGISTIC REGRESSION|     P=0.025N*    P=0.105N     P=0.220N     P=0.032N*   |(e)          (e)          (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.025N*    P=0.102N     P=0.218N     P=0.028N*   |(e)          (e)          (e)          (e)          |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 7
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Adenoma                                                                                                      |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     19/50 (38%)  17/50 (34%)  13/50 (26%)  18/50 (36%) |9/50 (18%)   7/50 (14%)   3/50 (6%)    6/50 (12%)   |
|POLY-3 ADJUSTED (b)|     40.1%        35.4%        27.3%        38.5%       |19.5%        15.2%        6.4%         12.9%        |
|TERMINAL (d)       |     16/39 (41%)  16/45 (36%)  13/42 (31%)  14/39 (36%) |8/40 (20%)   5/34 (15%)   3/37 (8%)    6/41 (15%)   |
|FIRST INCIDENCE    |     643          637          727 (T)      472         |586          667          728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.514N     P=0.247N     P=0.095N     P=0.513N    |P=0.171N     P=0.506N     P=0.079N     P=0.271N     |
|POLY 3             |     P=0.473N     P=0.395N     P=0.134N     P=0.521N    |P=0.197N     P=0.394N     P=0.057N     P=0.283N     |
|POLY 1.5           |     P=0.463N     P=0.406N     P=0.136N     P=0.513N    |P=0.201N     P=0.392N     P=0.058N     P=0.287N     |
|POLY 6             |     P=0.486N     P=0.377N     P=0.135N     P=0.528N    |P=0.190N     P=0.406N     P=0.055N     P=0.276N     |
|LOGISTIC REGRESSION|     P=0.504N     P=0.374N     P=0.118N     P=0.534N    |P=0.184N     P=0.394N     P=0.056N     P=0.270N     |
|COCH-ARM / FISHERS |     P=0.450N     P=0.418N     P=0.142N     P=0.500N    |P=0.203N     P=0.393N     P=0.061N     P=0.288N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma                                                                                                    |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     9/50 (18%)   10/50 (20%)  6/50 (12%)   9/50 (18%)  |2/50 (4%)    2/50 (4%)    4/50 (8%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|     19.1%        20.6%        12.5%        19.3%       |4.4%         4.4%         8.5%         2.2%         |
|TERMINAL (d)       |     8/39 (21%)   8/45 (18%)   5/42 (12%)   5/39 (13%)  |2/40 (5%)    1/34 (3%)    3/37 (8%)    1/41 (2%)    |
|FIRST INCIDENCE    |     617          601          596          583         |728 (T)      673          691          728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.519N     P=0.585N     P=0.245N     P=0.588     |P=0.399N     P=0.645      P=0.312      P=0.491N     |
|POLY 3             |     P=0.490N     P=0.527      P=0.275N     P=0.591     |P=0.422N     P=0.693N     P=0.349      P=0.494N     |
|POLY 1.5           |     P=0.485N     P=0.514      P=0.280N     P=0.594     |P=0.428N     P=0.692N     P=0.344      P=0.498N     |
|POLY 6             |     P=0.493N     P=0.548      P=0.269N     P=0.594     |P=0.411N     P=0.690      P=0.354      P=0.489N     |
|LOGISTIC REGRESSION|     P=0.458N     P=0.499      P=0.287N     P=0.602N    |P=0.417N     P=0.692      P=0.351      P=0.491N     |
|COCH-ARM / FISHERS |     P=0.475N     P=0.500      P=0.288N     P=0.602N    |P=0.431N     P=0.691N     P=0.339      P=0.500N     |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 8
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma or Hepatoblastoma                                                                                  |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     12/50 (24%)  11/50 (22%)  7/50 (14%)   9/50 (18%)  |2/50 (4%)    2/50 (4%)    4/50 (8%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|     25.4%        22.7%        14.6%        19.3%       |4.4%         4.4%         8.5%         2.2%         |
|TERMINAL (d)       |     10/39 (26%)  9/45 (20%)   6/42 (14%)   5/39 (13%)  |2/40 (5%)    1/34 (3%)    3/37 (8%)    1/41 (2%)    |
|FIRST INCIDENCE    |     617          601          596          583         |728 (T)      673          691          728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.267N     P=0.374N     P=0.124N     P=0.332N    |P=0.399N     P=0.645      P=0.312      P=0.491N     |
|POLY 3             |     P=0.239N     P=0.472N     P=0.143N     P=0.325N    |P=0.422N     P=0.693N     P=0.349      P=0.494N     |
|POLY 1.5           |     P=0.235N     P=0.486N     P=0.147N     P=0.321N    |P=0.428N     P=0.692N     P=0.344      P=0.498N     |
|POLY 6             |     P=0.243N     P=0.451N     P=0.139N     P=0.324N    |P=0.411N     P=0.690      P=0.354      P=0.489N     |
|LOGISTIC REGRESSION|     P=0.219N     P=0.497N     P=0.150N     P=0.316N    |P=0.417N     P=0.692      P=0.351      P=0.491N     |
|COCH-ARM / FISHERS |     P=0.225N     P=0.500N     P=0.154N     P=0.312N    |P=0.431N     P=0.691N     P=0.339      P=0.500N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma or Hepatocellular Adenoma                                                                          |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     24/50 (48%)  24/50 (48%)  16/50 (32%)  25/50 (50%) |10/50 (20%)  8/50 (16%)   7/50 (14%)   7/50 (14%)   |
|POLY-3 ADJUSTED (b)|     50.2%        49.2%        33.3%        52.4%       |21.6%        17.3%        14.9%        15.1%        |
|TERMINAL (d)       |     20/39 (51%)  21/45 (47%)  15/42 (36%)  18/39 (46%) |9/40 (23%)   6/34 (18%)   6/37 (16%)   7/41 (17%)   |
|FIRST INCIDENCE    |     617          601          596          472         |586          667          691          728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.447      P=0.354N     P=0.048N*    P=0.482     |P=0.212N     P=0.523N     P=0.349N     P=0.278N     |
|POLY 3             |     P=0.516      P=0.539N     P=0.068N     P=0.499     |P=0.250N     P=0.399N     P=0.285N     P=0.292N     |
|POLY 1.5           |     P=0.521      P=0.558N     P=0.070N     P=0.498     |P=0.256N     P=0.396N     P=0.290N     P=0.296N     |
|POLY 6             |     P=0.513      P=0.508N     P=0.067N     P=0.508     |P=0.239N     P=0.412N     P=0.280N     P=0.284N     |
|LOGISTIC REGRESSION|     P=0.506      P=0.560N     P=0.066N     P=0.479     |P=0.229N     P=0.402N     P=0.277N     P=0.276N     |
|COCH-ARM / FISHERS |     P=0.529      P=0.579N     P=0.076N     P=0.500     |P=0.257N     P=0.398N     P=0.298N     P=0.298N     |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 9
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma, Hepatocellular Adenoma,                                                                           |
|     or Hepatoblastoma                                                                                                           |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     26/50 (52%)  25/50 (50%)  17/50 (34%)  25/50 (50%) |10/50 (20%)  8/50 (16%)   7/50 (14%)   7/50 (14%)   |
|POLY-3 ADJUSTED (b)|     54.3%        51.2%        35.4%        52.4%       |21.6%        17.3%        14.9%        15.1%        |
|TERMINAL (d)       |     21/39 (54%)  22/45 (49%)  16/42 (38%)  18/39 (46%) |9/40 (23%)   6/34 (18%)   6/37 (16%)   7/41 (17%)   |
|FIRST INCIDENCE    |     617          601          596          472         |586          667          691          728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.484N     P=0.279N     P=0.033N*    P=0.520N    |P=0.212N     P=0.523N     P=0.349N     P=0.278N     |
|POLY 3             |     P=0.410N     P=0.460N     P=0.046N*    P=0.506N    |P=0.250N     P=0.399N     P=0.285N     P=0.292N     |
|POLY 1.5           |     P=0.404N     P=0.479N     P=0.048N*    P=0.505N    |P=0.256N     P=0.396N     P=0.290N     P=0.296N     |
|POLY 6             |     P=0.415N     P=0.430N     P=0.046N*    P=0.501N    |P=0.239N     P=0.412N     P=0.280N     P=0.284N     |
|LOGISTIC REGRESSION|     P=0.422N     P=0.478N     P=0.044N*    P=0.524N    |P=0.229N     P=0.402N     P=0.277N     P=0.276N     |
|COCH-ARM / FISHERS |     P=0.396N     P=0.500N     P=0.053N     P=0.500N    |P=0.257N     P=0.398N     P=0.298N     P=0.298N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Adenoma                                                                                                |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     10/50 (20%)  5/50 (10%)   9/50 (18%)   10/50 (20%) |1/50 (2%)    4/50 (8%)    3/50 (6%)    5/50 (10%)   |
|POLY-3 ADJUSTED (b)|     21.2%        10.4%        18.9%        22.0%       |2.2%         8.7%         6.4%         10.8%        |
|TERMINAL (d)       |     9/39 (23%)   4/45 (9%)    8/42 (19%)   10/39 (26%) |1/40 (3%)    2/34 (6%)    3/37 (8%)    5/41 (12%)   |
|FIRST INCIDENCE    |     617          644          707          727 (T)     |728 (T)      659          728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.333      P=0.087N     P=0.433N     P=0.596     |P=0.142      P=0.154      P=0.278      P=0.109      |
|POLY 3             |     P=0.335      P=0.121N     P=0.490N     P=0.562     |P=0.118      P=0.181      P=0.313      P=0.105      |
|POLY 1.5           |     P=0.352      P=0.126N     P=0.494N     P=0.576     |P=0.115      P=0.181      P=0.310      P=0.103      |
|POLY 6             |     P=0.315      P=0.114N     P=0.487N     P=0.546     |P=0.123      P=0.178      P=0.316      P=0.108      |
|LOGISTIC REGRESSION|     P=0.327      P=0.127N     P=0.477N     P=0.558     |P=0.122      P=0.179      P=0.278      P=0.109      |
|COCH-ARM / FISHERS |     P=0.375      P=0.131N     P=0.500N     P=0.598N    |P=0.113      P=0.181      P=0.309      P=0.102      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 10
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma                                                                                              |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     4/50 (8%)    1/50 (2%)    3/50 (6%)    7/50 (14%)  |0/50 (0%)    3/50 (6%)    2/50 (4%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|     8.4%         2.1%         6.3%         15.1%       |0.0%         6.6%         4.3%         2.2%         |
|TERMINAL (d)       |     3/39 (8%)    1/45 (2%)    3/42 (7%)    5/39 (13%)  |0/40 (0%)    3/34 (9%)    2/37 (5%)    1/41 (2%)    |
|FIRST INCIDENCE    |     526          727 (T)      727 (T)      502         |---          728 (T)      728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.070      P=0.149N     P=0.464N     P=0.262     |P=0.580      P=0.094      P=0.221      P=0.505      |
|POLY 3             |     P=0.074      P=0.177N     P=0.498N     P=0.249     |P=0.566      P=0.118      P=0.242      P=0.503      |
|POLY 1.5           |     P=0.076      P=0.178N     P=0.499N     P=0.254     |P=0.560      P=0.119      P=0.240      P=0.501      |
|POLY 6             |     P=0.071      P=0.173N     P=0.497N     P=0.246     |P=0.575      P=0.115      P=0.244      P=0.506      |
|LOGISTIC REGRESSION|     P=0.098      P=0.185N     P=0.525N     P=0.304     |(e)          P=0.094      P=0.221      P=0.505      |
|COCH-ARM / FISHERS |     P=0.080      P=0.181N     P=0.500N     P=0.262     |P=0.556      P=0.121      P=0.247      P=0.500      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar                                                                      |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     13/50 (26%)  6/50 (12%)   12/50 (24%)  17/50 (34%) |1/50 (2%)    6/50 (12%)   5/50 (10%)   6/50 (12%)   |
|POLY-3 ADJUSTED (b)|     27.2%        12.5%        25.2%        36.6%       |2.2%         13.0%        10.7%        12.9%        |
|TERMINAL (d)       |     11/39 (28%)  5/45 (11%)   11/42 (26%)  15/39 (39%) |1/40 (3%)    4/34 (12%)   5/37 (14%)   6/41 (15%)   |
|FIRST INCIDENCE    |     526          644          707          502         |728 (T)      659          728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.056      P=0.037N*    P=0.422N     P=0.253     |P=0.136      P=0.044 *    P=0.086      P=0.062      |
|POLY 3             |     P=0.057      P=0.059N     P=0.503N     P=0.223     |P=0.110      P=0.057      P=0.106      P=0.059      |
|POLY 1.5           |     P=0.063      P=0.061N     P=0.501N     P=0.236     |P=0.107      P=0.057      P=0.105      P=0.057      |
|POLY 6             |     P=0.051      P=0.055N     P=0.506N     P=0.211     |P=0.116      P=0.055      P=0.108      P=0.061      |
|LOGISTIC REGRESSION|     P=0.066      P=0.065N     P=0.490N     P=0.248     |P=0.120      P=0.058      P=0.086      P=0.062      |
|COCH-ARM / FISHERS |     P=0.073      P=0.062N     P=0.500N     P=0.257     |P=0.105      P=0.056      P=0.102      P=0.056      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 11
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Ovary                                                                                                                            |
|     Cystadenoma                                                                                                                 |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |                                                        |0/47 (0%)    2/49 (4%)    1/50 (2%)    3/49 (6%)    |
|POLY-3 ADJUSTED (b)|                                                        |0.0%         4.5%         2.1%         6.6%         |
|TERMINAL (d)       |                                                        |0/37 (0%)    2/33 (6%)    1/37 (3%)    3/40 (8%)    |
|FIRST INCIDENCE    |                                                        |---          728 (T)      728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |                                                        |P=0.130      P=0.213      P=0.500      P=0.135      |
|POLY 3             |                                                        |P=0.113      P=0.247      P=0.518      P=0.130      |
|POLY 1.5           |                                                        |P=0.111      P=0.248      P=0.516      P=0.128      |
|POLY 6             |                                                        |P=0.117      P=0.243      P=0.520      P=0.133      |
|LOGISTIC REGRESSION|                                                        |(e)          P=0.213      P=0.500      P=0.135      |
|COCH-ARM / FISHERS |                                                        |P=0.108      P=0.258      P=0.515      P=0.129      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Ovary                                                                                                                            |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |                                                        |0/47 (0%)    2/49 (4%)    1/50 (2%)    1/49 (2%)    |
|POLY-3 ADJUSTED (b)|                                                        |0.0%         4.5%         2.1%         2.2%         |
|TERMINAL (d)       |                                                        |0/37 (0%)    2/33 (6%)    1/37 (3%)    1/40 (3%)    |
|FIRST INCIDENCE    |                                                        |---          728 (T)      728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |                                                        |P=0.535      P=0.213      P=0.500      P=0.516      |
|POLY 3             |                                                        |P=0.520      P=0.247      P=0.518      P=0.512      |
|POLY 1.5           |                                                        |P=0.515      P=0.248      P=0.516      P=0.510      |
|POLY 6             |                                                        |P=0.528      P=0.243      P=0.520      P=0.516      |
|LOGISTIC REGRESSION|                                                        |(e)          P=0.213      P=0.500      P=0.516      |
|COCH-ARM / FISHERS |                                                        |P=0.511      P=0.258      P=0.515      P=0.510      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 12
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/49 (0%)    0/49 (0%)    0/47 (0%)    0/47 (0%)   |1/48 (2%)    3/47 (6%)    0/43 (0%)    1/48 (2%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |2.3%         6.9%         0.0%         2.2%         |
|TERMINAL (d)       |     0/38 (0%)    0/44 (0%)    0/40 (0%)    0/37 (0%)   |1/38 (3%)    2/32 (6%)    0/33 (0%)    1/40 (3%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |728 (T)      643          ---          728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.384N     P=0.273      P=0.528N     P=0.750N     |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.401N     P=0.305      P=0.515N     P=0.754N     |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.406N     P=0.303      P=0.518N     P=0.757N     |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.396N     P=0.301      P=0.513N     P=0.749N     |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.408N     P=0.299      (e)          P=0.750N     |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.412N     P=0.301      P=0.527N     P=0.753N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibroma, Fibrosarcoma, Sarcoma, Myxoma, Myxosarcoma,                                                                        |
|     or Fibrous Histiocytoma                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |1/50 (2%)    5/50 (10%)   1/50 (2%)    3/50 (6%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |2.2%         10.7%        2.1%         6.4%         |
|TERMINAL (d)       |     0/39 (0%)    0/45 (0%)    0/42 (0%)    0/39 (0%)   |0/40 (0%)    1/34 (3%)    0/37 (0%)    2/41 (5%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |586          651          477          705          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.491      P=0.103      P=0.753N     P=0.317      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.462      P=0.103      P=0.755N     P=0.308      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.459      P=0.103      P=0.757N     P=0.306      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.468      P=0.101      P=0.753N     P=0.312      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.474      P=0.081      P=0.741      P=0.303      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.456      P=0.102      P=0.753N     P=0.309      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 13
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibrosarcoma                                                                                                                |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |0/50 (0%)    5/50 (10%)   1/50 (2%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |0.0%         10.7%        2.1%         4.3%         |
|TERMINAL (d)       |     0/39 (0%)    0/45 (0%)    0/42 (0%)    0/39 (0%)   |0/40 (0%)    1/34 (3%)    0/37 (0%)    1/41 (2%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |---          651          477          705          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.534      P=0.032 *    P=0.504      P=0.248      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.514      P=0.032 *    P=0.507      P=0.241      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.507      P=0.032 *    P=0.505      P=0.239      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.524      P=0.032 *    P=0.510      P=0.245      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.517      P=0.029 *    P=0.405      P=0.241      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.500      P=0.028 *    P=0.500      P=0.247      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibrosarcoma, Sarcoma, Myxosarcoma, or Fibrous Histiocytoma                                                                 |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |1/50 (2%)    5/50 (10%)   1/50 (2%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |2.2%         10.7%        2.1%         4.3%         |
|TERMINAL (d)       |     0/39 (0%)    0/45 (0%)    0/42 (0%)    0/39 (0%)   |0/40 (0%)    1/34 (3%)    0/37 (0%)    1/41 (2%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |586          651          477          705          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.491N     P=0.103      P=0.753N     P=0.508      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.517N     P=0.103      P=0.755N     P=0.503      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.520N     P=0.103      P=0.757N     P=0.501      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.512N     P=0.101      P=0.753N     P=0.506      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.498N     P=0.081      P=0.741      P=0.501      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.523N     P=0.102      P=0.753N     P=0.500      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 14
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Schwannoma Malignant                                                                                                        |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |0.0%         0.0%         0.0%         4.2%         |
|TERMINAL (d)       |     0/39 (0%)    0/45 (0%)    0/42 (0%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    1/41 (2%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |---          ---          ---          520          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.051      (e)          (e)          P=0.240      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.047 *    (e)          (e)          P=0.244      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.046 *    (e)          (e)          P=0.241      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.048 *    (e)          (e)          P=0.249      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.060      (e)          (e)          P=0.249      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.046 *    (e)          (e)          P=0.247      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Spleen                                                                                                                           |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     3/50 (6%)    0/50 (0%)    2/50 (4%)    0/50 (0%)   |0/49 (0%)    1/50 (2%)    2/50 (4%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     6.4%         0.0%         4.2%         0.0%        |0.0%         2.2%         4.3%         0.0%         |
|TERMINAL (d)       |     2/39 (5%)    0/45 (0%)    1/42 (2%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    2/37 (5%)    0/41 (0%)    |
|FIRST INCIDENCE    |     661          ---          707          ---         |---          605          728 (T)      ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.131N     P=0.105N     P=0.472N     P=0.126N    |P=0.602N     P=0.517      P=0.221      (e)          |
|POLY 3             |     P=0.131N     P=0.116N     P=0.494N     P=0.125N    |P=0.610N     P=0.503      P=0.244      (e)          |
|POLY 1.5           |     P=0.128N     P=0.118N     P=0.496N     P=0.123N    |P=0.612N     P=0.504      P=0.243      (e)          |
|POLY 6             |     P=0.135N     P=0.114N     P=0.492N     P=0.128N    |P=0.605N     P=0.500      P=0.245      (e)          |
|LOGISTIC REGRESSION|     P=0.125N     P=0.122N     P=0.501N     P=0.121N    |P=0.607N     P=0.459      P=0.221      (e)          |
|COCH-ARM / FISHERS |     P=0.125N     P=0.121N     P=0.500N     P=0.121N    |P=0.612N     P=0.505      P=0.253      (e)          |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 15
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Stomach, Forestomach                                                                                                             |
|     Squamous Cell Carcinoma                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |0.0%         0.0%         0.0%         4.3%         |
|TERMINAL (d)       |     0/39 (0%)    0/45 (0%)    0/42 (0%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    2/41 (5%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |---          ---          ---          728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.055      (e)          (e)          P=0.244      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.046 *    (e)          (e)          P=0.241      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.046 *    (e)          (e)          P=0.239      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.047 *    (e)          (e)          P=0.244      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |(e)          (e)          (e)          P=0.244      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.046 *    (e)          (e)          P=0.247      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Stomach, Forestomach                                                                                                             |
|     Squamous Cell Carcinoma or Papilloma Squamous                                                                               |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    1/50 (2%)    0/50 (0%)    1/50 (2%)   |1/50 (2%)    0/50 (0%)    1/50 (2%)    5/50 (10%)   |
|POLY-3 ADJUSTED (b)|     2.1%         2.1%         0.0%         2.2%        |2.2%         0.0%         2.1%         10.7%        |
|TERMINAL (d)       |     1/39 (3%)    1/45 (2%)    0/42 (0%)    1/39 (3%)   |1/40 (3%)    0/34 (0%)    1/37 (3%)    4/41 (10%)   |
|FIRST INCIDENCE    |     727 (T)      727 (T)      ---          727 (T)     |728 (T)      ---          728 (T)      708          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.629N     P=0.730N     P=0.485N     P=0.762     |P=0.016 *    P=0.532N     P=0.744      P=0.111      |
|POLY 3             |     P=0.616N     P=0.756N     P=0.497N     P=0.754     |P=0.011 *    P=0.500N     P=0.756N     P=0.106      |
|POLY 1.5           |     P=0.616N     P=0.758N     P=0.498N     P=0.756     |P=0.011 *    P=0.500N     P=0.758N     P=0.104      |
|POLY 6             |     P=0.617N     P=0.752N     P=0.495N     P=0.752     |P=0.012 *    P=0.504N     P=0.754N     P=0.109      |
|LOGISTIC REGRESSION|     P=0.629N     P=0.730N     (e)          P=0.762     |P=0.014 *    (e)          P=0.744      P=0.112      |
|COCH-ARM / FISHERS |     P=0.616N     P=0.753N     P=0.500N     P=0.753N    |P=0.011 *    P=0.500N     P=0.753N     P=0.102      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 16
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Stomach, Forestomach                                                                                                             |
|     Squamous Cell Papilloma                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    1/50 (2%)    0/50 (0%)    1/50 (2%)   |1/50 (2%)    0/50 (0%)    1/50 (2%)    3/50 (6%)    |
|POLY-3 ADJUSTED (b)|     2.1%         2.1%         0.0%         2.2%        |2.2%         0.0%         2.1%         6.4%         |
|TERMINAL (d)       |     1/39 (3%)    1/45 (2%)    0/42 (0%)    1/39 (3%)   |1/40 (3%)    0/34 (0%)    1/37 (3%)    2/41 (5%)    |
|FIRST INCIDENCE    |     727 (T)      727 (T)      ---          727 (T)     |728 (T)      ---          728 (T)      708          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.629N     P=0.730N     P=0.485N     P=0.762     |P=0.114      P=0.532N     P=0.744      P=0.316      |
|POLY 3             |     P=0.616N     P=0.756N     P=0.497N     P=0.754     |P=0.099      P=0.500N     P=0.756N     P=0.312      |
|POLY 1.5           |     P=0.616N     P=0.758N     P=0.498N     P=0.756     |P=0.097      P=0.500N     P=0.758N     P=0.308      |
|POLY 6             |     P=0.617N     P=0.752N     P=0.495N     P=0.752     |P=0.103      P=0.504N     P=0.754N     P=0.318      |
|LOGISTIC REGRESSION|     P=0.629N     P=0.730N     (e)          P=0.762     |P=0.108      (e)          P=0.744      P=0.317      |
|COCH-ARM / FISHERS |     P=0.616N     P=0.753N     P=0.500N     P=0.753N    |P=0.097      P=0.500N     P=0.753N     P=0.309      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Testes                                                                                                                           |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    2/50 (4%)    0/50 (0%)    0/50 (0%)   |                                                    |
|POLY-3 ADJUSTED (b)|     0.0%         4.2%         0.0%         0.0%        |                                                    |
|TERMINAL (d)       |     0/39 (0%)    2/45 (4%)    0/42 (0%)    0/39 (0%)   |                                                    |
|FIRST INCIDENCE    |     ---          727 (T)      ---          ---         |                                                    |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.412N     P=0.270      (e)          (e)         |                                                    |
|POLY 3             |     P=0.405N     P=0.242      (e)          (e)         |                                                    |
|POLY 1.5           |     P=0.405N     P=0.240      (e)          (e)         |                                                    |
|POLY 6             |     P=0.404N     P=0.246      (e)          (e)         |                                                    |
|LOGISTIC REGRESSION|     (e)          P=0.270      (e)          (e)         |                                                    |
|COCH-ARM / FISHERS |     P=0.405N     P=0.247      (e)          (e)         |                                                    |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 17
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Tooth                                                                                                                            |
|     Odontoma                                                                                                                    |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    2/50 (4%)    1/50 (2%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     0.0%         4.2%         2.1%         0.0%        |0.0%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     0/39 (0%)    2/45 (4%)    1/42 (2%)    0/39 (0%)   |0/40 (0%)    0/34 (0%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |     ---          727 (T)      727 (T)      ---         |---          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.471N     P=0.270      P=0.515      (e)         |(e)          (e)          (e)          (e)          |
|POLY 3             |     P=0.469N     P=0.242      P=0.503      (e)         |(e)          (e)          (e)          (e)          |
|POLY 1.5           |     P=0.466N     P=0.240      P=0.502      (e)         |(e)          (e)          (e)          (e)          |
|POLY 6             |     P=0.471N     P=0.246      P=0.505      (e)         |(e)          (e)          (e)          (e)          |
|LOGISTIC REGRESSION|     (e)          P=0.270      P=0.515      (e)         |(e)          (e)          (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.461N     P=0.247      P=0.500      (e)         |(e)          (e)          (e)          (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Polyp Stromal                                                                                                               |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |                                                        |0/50 (0%)    3/50 (6%)    0/50 (0%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|                                                        |0.0%         6.5%         0.0%         2.1%         |
|TERMINAL (d)       |                                                        |0/40 (0%)    1/34 (3%)    0/37 (0%)    0/41 (0%)    |
|FIRST INCIDENCE    |                                                        |---          664          ---          659          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |                                                        |P=0.607N     P=0.107      (e)          P=0.518      |
|POLY 3             |                                                        |P=0.627N     P=0.120      (e)          P=0.504      |
|POLY 1.5           |                                                        |P=0.631N     P=0.120      (e)          P=0.502      |
|POLY 6             |                                                        |P=0.624N     P=0.117      (e)          P=0.508      |
|LOGISTIC REGRESSION|                                                        |P=0.633N     P=0.120      (e)          P=0.504      |
|COCH-ARM / FISHERS |                                                        |P=0.634      P=0.121      (e)          P=0.500      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 18
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |0/50 (0%)    2/50 (4%)    1/50 (2%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |0.0%         4.4%         2.1%         2.2%         |
|TERMINAL (d)       |     0/39 (0%)    0/45 (0%)    0/42 (0%)    0/39 (0%)   |0/40 (0%)    2/34 (6%)    1/37 (3%)    1/41 (2%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |---          728 (T)      728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.521      P=0.203      P=0.484      P=0.505      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.508      P=0.237      P=0.504      P=0.503      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.503      P=0.238      P=0.503      P=0.501      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.515      P=0.233      P=0.506      P=0.506      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |(e)          P=0.203      P=0.484      P=0.505      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.500      P=0.247      P=0.500      P=0.500      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     7/50 (14%)   2/50 (4%)    3/50 (6%)    2/50 (4%)   |1/50 (2%)    1/50 (2%)    3/50 (6%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     14.9%        4.2%         6.3%         4.3%        |2.2%         2.2%         6.4%         0.0%         |
|TERMINAL (d)       |     5/39 (13%)   2/45 (4%)    1/42 (2%)    0/39 (0%)   |1/40 (3%)    0/34 (0%)    3/37 (8%)    0/41 (0%)    |
|FIRST INCIDENCE    |     661          727 (T)      664          549         |728 (T)      605          728 (T)      ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.091N     P=0.059N     P=0.142N     P=0.092N    |P=0.393N     P=0.752      P=0.278      P=0.495N     |
|POLY 3             |     P=0.083N     P=0.076N     P=0.151N     P=0.084N    |P=0.402N     P=0.759N     P=0.313      P=0.497N     |
|POLY 1.5           |     P=0.082N     P=0.078N     P=0.154N     P=0.083N    |P=0.407N     P=0.759N     P=0.310      P=0.499N     |
|POLY 6             |     P=0.085N     P=0.073N     P=0.148N     P=0.086N    |P=0.393N     P=0.760      P=0.316      P=0.494N     |
|LOGISTIC REGRESSION|     P=0.073N     P=0.076N     P=0.159N     P=0.073N    |P=0.410N     P=0.748      P=0.278      (e)          |
|COCH-ARM / FISHERS |     P=0.080N     P=0.080N     P=0.159N     P=0.080N    |P=0.409N     P=0.753N     P=0.309      P=0.500N     |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 19
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma or Hemangioma                                                                                               |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     7/50 (14%)   2/50 (4%)    3/50 (6%)    2/50 (4%)   |1/50 (2%)    3/50 (6%)    4/50 (8%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|     14.9%        4.2%         6.3%         4.3%        |2.2%         6.5%         8.6%         2.2%         |
|TERMINAL (d)       |     5/39 (13%)   2/45 (4%)    1/42 (2%)    0/39 (0%)   |1/40 (3%)    2/34 (6%)    4/37 (11%)   1/41 (2%)    |
|FIRST INCIDENCE    |     661          727 (T)      664          549         |728 (T)      605          728 (T)      728 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.091N     P=0.059N     P=0.142N     P=0.092N    |P=0.494N     P=0.272      P=0.156      P=0.756N     |
|POLY 3             |     P=0.083N     P=0.076N     P=0.151N     P=0.084N    |P=0.513N     P=0.308      P=0.185      P=0.757N     |
|POLY 1.5           |     P=0.082N     P=0.078N     P=0.154N     P=0.083N    |P=0.519N     P=0.308      P=0.183      P=0.759N     |
|POLY 6             |     P=0.085N     P=0.073N     P=0.148N     P=0.086N    |P=0.502N     P=0.304      P=0.188      P=0.754N     |
|LOGISTIC REGRESSION|     P=0.073N     P=0.076N     P=0.159N     P=0.073N    |P=0.514N     P=0.303      P=0.156      P=0.756N     |
|COCH-ARM / FISHERS |     P=0.080N     P=0.080N     P=0.159N     P=0.080N    |P=0.523N     P=0.309      P=0.181      P=0.753N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Lymphoma: Histiocytic, Lymphocytic, Mixed,                                                                        |
|     NOS, or Undifferentiated Cell Type                                                                                          |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    1/50 (2%)    4/50 (8%)    1/50 (2%)   |7/50 (14%)   10/50 (20%)  8/50 (16%)   6/50 (12%)   |
|POLY-3 ADJUSTED (b)|     2.1%         2.1%         8.4%         2.2%        |14.9%        21.5%        16.7%        12.8%        |
|TERMINAL (d)       |     1/39 (3%)    1/45 (2%)    3/42 (7%)    0/39 (0%)   |4/40 (10%)   7/34 (21%)   4/37 (11%)   4/41 (10%)   |
|FIRST INCIDENCE    |     727 (T)      727 (T)      664          594         |580          650          524          673          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.508      P=0.730N     P=0.203      P=0.753     |P=0.295N     P=0.248      P=0.471      P=0.474N     |
|POLY 3             |     P=0.508      P=0.756N     P=0.186      P=0.756     |P=0.331N     P=0.288      P=0.515      P=0.502N     |
|POLY 1.5           |     P=0.515      P=0.758N     P=0.183      P=0.758     |P=0.335N     P=0.295      P=0.510      P=0.503N     |
|POLY 6             |     P=0.501      P=0.752N     P=0.189      P=0.755     |P=0.322N     P=0.272      P=0.518      P=0.498N     |
|LOGISTIC REGRESSION|     P=0.542      P=0.730N     P=0.182      P=0.734N    |P=0.338N     P=0.290      P=0.459      P=0.504N     |
|COCH-ARM / FISHERS |     P=0.526      P=0.753N     P=0.181      P=0.753N    |P=0.334N     P=0.298      P=0.500      P=0.500N     |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 20
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Benign Tumors                                                                                                               |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     28/50 (56%)  28/50 (56%)  26/50 (52%)  29/50 (58%) |13/50 (26%)  22/50 (44%)  14/50 (28%)  20/50 (40%)  |
|POLY-3 ADJUSTED (b)|     58.1%        57.4%        54.6%        62.0%       |28.1%        46.6%        29.6%        42.7%        |
|TERMINAL (d)       |     22/39 (56%)  25/45 (56%)  25/42 (60%)  25/39 (64%) |12/40 (30%)  15/34 (44%)  12/37 (32%)  18/41 (44%)  |
|FIRST INCIDENCE    |     617          612          707          472         |586          643          610          659          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.373      P=0.328N     P=0.294N     P=0.480     |P=0.299      P=0.021 *    P=0.421      P=0.118      |
|POLY 3             |     P=0.385      P=0.555N     P=0.444N     P=0.427     |P=0.208      P=0.048 *    P=0.526      P=0.103      |
|POLY 1.5           |     P=0.423      P=0.567N     P=0.430N     P=0.459     |P=0.202      P=0.047 *    P=0.515      P=0.100      |
|POLY 6             |     P=0.333      P=0.535N     P=0.475N     P=0.385     |P=0.223      P=0.048 *    P=0.538      P=0.111      |
|LOGISTIC REGRESSION|     P=0.382      P=0.559N     P=0.372N     P=0.435     |P=0.229      P=0.045 *    P=0.532      P=0.116      |
|COCH-ARM / FISHERS |     P=0.471      P=0.580N     P=0.421N     P=0.500     |P=0.203      P=0.046 *    P=0.500      P=0.101      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Tumors                                                                                                            |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     27/50 (54%)  15/50 (30%)  20/50 (40%)  20/50 (40%) |12/50 (24%)  21/50 (42%)  19/50 (38%)  17/50 (34%)  |
|POLY-3 ADJUSTED (b)|     54.9%        30.9%        40.8%        41.1%       |25.2%        43.5%        38.6%        35.1%        |
|TERMINAL (d)       |     20/39 (51%)  13/45 (29%)  15/42 (36%)  11/39 (28%) |7/40 (18%)   11/34 (32%)  11/37 (30%)  12/41 (29%)  |
|FIRST INCIDENCE    |     501          601          596          502         |580          605          477          401          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.316N     P=0.006N**   P=0.095N     P=0.170N    |P=0.405      P=0.042 *    P=0.104      P=0.235      |
|POLY 3             |     P=0.234N     P=0.013N*    P=0.116N     P=0.121N    |P=0.320      P=0.045 *    P=0.113      P=0.201      |
|POLY 1.5           |     P=0.234N     P=0.012N*    P=0.116N     P=0.120N    |P=0.312      P=0.044 *    P=0.107      P=0.196      |
|POLY 6             |     P=0.229N     P=0.012N*    P=0.115N     P=0.117N    |P=0.329      P=0.044 *    P=0.118      P=0.205      |
|LOGISTIC REGRESSION|     P=0.176N     P=0.014N*    P=0.131N     P=0.078N    |P=0.270      P=0.039 *    P=0.069      P=0.175      |
|COCH-ARM / FISHERS |     P=0.233N     P=0.013N*    P=0.115N     P=0.115N    |P=0.299      P=0.044 *    P=0.097      P=0.189      |
|=================================================================================================================================|
       Date:  05/13/99                           EXPERIMENT: 88007 TEST: 06                                            Page 21
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                   SODIUM NITRITE
                                         Terminal Sacrifice at 104 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     0.0%         0.075%       0.15%        0.30%       |0.0%         0.075%       0.15%        0.30%        |
|                   |                                                        |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant and Benign Tumors                                                                                                 |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     40/50 (80%)  35/50 (70%)  36/50 (72%)  38/50 (76%) |21/50 (42%)  33/50 (66%)  31/50 (62%)  32/50 (64%)  |
|POLY-3 ADJUSTED (b)|     80.5%        71.1%        73.5%        76.8%       |44.0%        67.4%        63.0%        65.6%        |
|TERMINAL (d)       |     30/39 (77%)  31/45 (69%)  31/42 (74%)  28/39 (72%) |16/40 (40%)  20/34 (59%)  22/37 (60%)  25/41 (61%)  |
|FIRST INCIDENCE    |     501          601          596          472         |580          605          477          401          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.469      P=0.063N     P=0.162N     P=0.461N    |P=0.156      P=0.012 *    P=0.037 *    P=0.052      |
|POLY 3             |     P=0.479N     P=0.196N     P=0.279N     P=0.423N    |P=0.054      P=0.015 *    P=0.045 *    P=0.024 *    |
|POLY 1.5           |     P=0.473N     P=0.192N     P=0.262N     P=0.417N    |P=0.050      P=0.014 *    P=0.041 *    P=0.023 *    |
|POLY 6             |     P=0.487N     P=0.193N     P=0.304N     P=0.425N    |P=0.060      P=0.017 *    P=0.048 *    P=0.028 *    |
|LOGISTIC REGRESSION|     P=0.454N     P=0.181N     P=0.242N     P=0.370N    |P=0.045 *    P=0.013 *    P=0.033 *    P=0.023 *    |
|COCH-ARM / FISHERS |     P=0.467N     P=0.178N     P=0.241N     P=0.405N    |P=0.047 *    P=0.013 *    P=0.036 *    P=0.022 *    |
|=================================================================================================================================|

(a)  Number of tumor-bearing animals /  number of animals examined at site.
(b)  Poly-3 adjusted lifetime tumor incidence.
(d)  Observed incidence at terminal kill.
(f)  Beneath the control incidence are the P-values associated with the trend 
test.  Beneath the dosed group incidence are the P-values corresponding to 
pairwise comparisons between the controls and that dosed group.  The life
table analysis regards tumors in animals dying prior to  terminal kill as
 being (directly or indirectly) the cause of death.
Logistic regression is an alternative
 method for analyzing the incidence of non-fatal tumors. The Cochran-Armitage
and Fishers exact tests compare directly the overall incidence rates
For all tests a negative trend is indicated by N
(e)  Value of Statistic cannot be computed.
(I)  Interim sacrifice
(T)  Terminal sacrifice
#   Tumor rates based on number of animals necropsied.
*   To the right of any statistical result, indicates significance at (P<=0.05).
**  To the right of any statistical result, indicates significance at (P<=0.01).