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TDMS Study 88034-06 Pathology Tables

NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: Battelle Northwest                                          OZONE                                         DATE: 05/08/95       
EXPERIMENT: 88034 TEST: 06                                                                                     TIME: 22:35:19       
TEST TYPE:  CHRONIC 30-MONTH                    CAGES FROM 0000 TO LAST CAGE                                   PAGE:       1        
CONT: N01-ES-95239          ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                                             NTP C#: 88034B       
PATHOLOGIST: S. GRUMBEIN                                                                                       CAS: 10028-15-6      
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
               REASONS FOR REMOVAL:    ALL                                                                                          
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
               REMOVAL DATE RANGE:     ALL                                                                                          
                                                                                                                                    
               TREATMENT GROUPS:       INCLUDE ALL                                                                                  
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: Battelle Northwest                                          OZONE                                         DATE: 05/08/95       
EXPERIMENT: 88034 TEST: 06                                                                                     TIME: 22:35:19       
TEST TYPE:  CHRONIC 30-MONTH                    CAGES FROM 0000 TO LAST CAGE                                                        
CONT: N01-ES-95239          ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                                             NTP C#: 88034B       
PATHOLOGIST: S. GRUMBEIN                                                                                       CAS: 10028-15-6      


                                                    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 NUMBER OF ANIMALS NECROPSIED.
                                                                    
                                                    ----------------
                                                    Adrenal Cortex
                                                    Adrenal Medulla
                                                    Bone Marrow
                                                    Brain
                                                    Clitoral Gland
                                                    Epididymis
                                                    Gallbladder
                                                    Heart
                                                    Islets, Pancreatic
                                                    Kidney
                                                    Larynx
                                                    Liver
                                                    Lung
                                                    Nose
                                                    Ovary
                                                    Pancreas
                                                    Parathyroid Gland
                                                    Pituitary Gland
                                                    Preputial Gland
                                                    Prostate
                                                    Salivary Glands
                                                    Spleen
                                                    Testes
                                                    Thymus
                                                    Thyroid Gland
                                                    Urinary Bladder
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: Battelle Northwest                                          OZONE                                         DATE: 05/08/95       
EXPERIMENT: 88034 TEST: 06                                                                                     TIME: 22:35:19       
TEST TYPE:  CHRONIC 30-MONTH                    CAGES FROM 0000 TO LAST CAGE                                                        
CONT: N01-ES-95239          ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                                             NTP C#: 88034B       
PATHOLOGIST: S. GRUMBEIN                                                                                       CAS: 10028-15-6      


                                     SUMMARY OF STATISTICALLY SIGNIFICANT (P<=.05) RESULTS
                                            IN THE ANALYSIS OF THE STUDY OF 6  OZONE
              ====================================================================================================
                                                           MALE MICE
                                                          -------------
                  ORGAN                               MORPHOLOGY
                 -------                             ------------
              Lung                          Alveolar/Bronchiolar Carcinoma
              Pituitary Gland: Pars Intermedia
                                            Adenoma
              All Organs                    Malignant Tumors
                                            Malignant and Benign Tumors
              ====================================================================================================
                                                           FEMALE MICE
                                                          -------------
                  ORGAN                               MORPHOLOGY
                 -------                             ------------
              Liver                         Hepatocellular Carcinoma
              Lung                          Alveolar/Bronchiolar Adenoma
              Pituitary Gland: Pars Distalis or Unspecified Site
                                            Adenoma
                                            Carcinoma or Adenoma
              All Organs                    Histiocytic Sarcoma
              ====================================================================================================
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   1
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Cortex                                                                                                                   |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/47 (4%)       1/49 (2%)       1/49 (2%)      |     1/48 (2%)       0/49 (0%)       1/50 (2%)      |
|ADJUSTED (b)           |     13.8%            5.3%            8.3%          |      5.3%            0.0%           10.0%          |
|TERMINAL (d)           |     1/13 (8%)       0/11 (0%)       1/12 (8%)      |     0/9 (0%)        0/12 (0%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      903             838             911 (T)       |      841             ---             911 (T)       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.437N        P=0.572N        P=0.545N       |     P=0.653N        P=0.453N        P=0.737N       |
|INCIDENTAL TUMOR       |     P=0.397N        P=0.479N        P=0.523N       |     P=0.649N        P=0.507N        P=0.738N       |
|LOGISTIC REGRESSION    |     P=0.435N        P=0.540N        P=0.565N       |     P=0.668N        P=0.478N        P=0.757N       |
|COCHRAN-ARMITAGE       |     P=0.365N                                       |     P=0.660N                                       |
|FISHER EXACT           |                     P=0.484N        P=0.484N       |                     P=0.495N        P=0.742N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Medulla                                                                                                                  |
|     Pheochromocytoma Benign                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     1/48 (2%)       0/48 (0%)       0/49 (0%)      |     2/48 (4%)       2/49 (4%)       1/50 (2%)      |
|ADJUSTED (b)           |      7.1%            0.0%            0.0%          |     13.2%           10.5%           10.0%          |
|TERMINAL (d)           |     1/14 (7%)       0/11 (0%)       0/12 (0%)      |     1/9 (11%)       1/12 (8%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      911 (T)         ---             ---           |      621             678             911 (T)       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.297N        P=0.548N        P=0.531N       |     P=0.369N        P=0.635N        P=0.473N       |
|INCIDENTAL TUMOR       |     P=0.297N        P=0.548N        P=0.531N       |     P=0.356N        P=0.581N        P=0.475N       |
|LOGISTIC REGRESSION    |     P=0.297N        P=0.548N        P=0.531N       |     P=0.379N        P=0.697N        P=0.493N       |
|COCHRAN-ARMITAGE       |     P=0.267N                                       |     P=0.376N                                       |
|FISHER EXACT           |                     P=0.500N        P=0.495N       |                     P=0.684N        P=0.485N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   2
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Medulla                                                                                                                  |
|     Pheochromocytoma: Benign, Complex, Malignant, NOS                                                                           |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     1/48 (2%)       0/48 (0%)       0/49 (0%)      |     2/48 (4%)       2/49 (4%)       2/50 (4%)      |
|ADJUSTED (b)           |      7.1%            0.0%            0.0%          |     13.2%           10.5%           16.9%          |
|TERMINAL (d)           |     1/14 (7%)       0/11 (0%)       0/12 (0%)      |     1/9 (11%)       1/12 (8%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      911 (T)         ---             ---           |      621             678             880           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.297N        P=0.548N        P=0.531N       |     P=0.577N        P=0.635N        P=0.658N       |
|INCIDENTAL TUMOR       |     P=0.297N        P=0.548N        P=0.531N       |     P=0.571N        P=0.581N        P=0.667N       |
|LOGISTIC REGRESSION    |     P=0.297N        P=0.548N        P=0.531N       |     P=0.594N        P=0.697N        P=0.692N       |
|COCHRAN-ARMITAGE       |     P=0.267N                                       |     P=0.585N                                       |
|FISHER EXACT           |                     P=0.500N        P=0.495N       |                     P=0.684N        P=0.676N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Bone                                                                                                                             |
|     Osteosarcoma                                                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       0/50 (0%)       1/50 (2%)      |     2/50 (4%)       1/50 (2%)       0/50 (0%)      |
|ADJUSTED (b)           |      0.0%            0.0%            3.6%          |      8.1%            3.1%            0.0%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             ---             741           |      403             786             ---           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.249           (e)           P=0.467        |     P=0.149N        P=0.465N        P=0.233N       |
|INCIDENTAL TUMOR       |     P=0.257           (e)           P=0.492        |     P=0.190N        P=0.677N        P=0.291N       |
|LOGISTIC REGRESSION    |     P=0.270           (e)           P=0.500        |     P=0.150N        P=0.604N        P=0.240N       |
|COCHRAN-ARMITAGE       |     P=0.269                                        |     P=0.142N                                       |
|FISHER EXACT           |                       (e)           P=0.500        |                     P=0.500N        P=0.247N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   3
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Bone Marrow                                                                                                                      |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     1/49 (2%)       2/49 (4%)       2/50 (4%)      |     1/49 (2%)       3/49 (6%)       1/50 (2%)      |
|ADJUSTED (b)           |      3.4%           11.0%            6.7%          |      2.3%           12.0%            2.3%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      791             787             677           |      621             571             646           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.320         P=0.450         P=0.449        |     P=0.583N        P=0.395         P=0.753N       |
|INCIDENTAL TUMOR       |     P=0.372         P=0.562         P=0.486        |     P=0.601N        P=0.416         P=0.754N       |
|LOGISTIC REGRESSION    |     P=0.387         P=0.495         P=0.508        |     P=0.597N        P=0.253         P=0.765        |
|COCHRAN-ARMITAGE       |     P=0.398                                        |     P=0.602N                                       |
|FISHER EXACT           |                     P=0.500         P=0.508        |                     P=0.309         P=0.747N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     6/50 (12%)      5/50 (10%)      4/50 (8%)      |     4/50 (8%)       4/50 (8%)       2/50 (4%)      |
|ADJUSTED (b)           |     24.9%           18.3%           25.4%          |     12.2%           22.4%           11.9%          |
|TERMINAL (d)           |     2/14 (14%)      0/11 (0%)       1/12 (8%)      |     0/9 (0%)        2/12 (17%)      1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      482             616             828           |      521             621             530           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.419N        P=0.575N        P=0.475N       |     P=0.272N        P=0.555N        P=0.371N       |
|INCIDENTAL TUMOR       |     P=0.313N        P=0.439N        P=0.458N       |     P=0.318N        P=0.622         P=0.400N       |
|LOGISTIC REGRESSION    |     P=0.326N        P=0.497N        P=0.410N       |     P=0.272N        P=0.631         P=0.332N       |
|COCHRAN-ARMITAGE       |     P=0.309N                                       |     P=0.274N                                       |
|FISHER EXACT           |                     P=0.500N        P=0.370N       |                     P=0.643N        P=0.339N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   4
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       2/50 (4%)       1/50 (2%)      |     1/50 (2%)       1/50 (2%)       1/50 (2%)      |
|ADJUSTED (b)           |      0.0%           13.6%            5.3%          |      2.8%            8.3%            5.9%          |
|TERMINAL (d)           |     0/14 (0%)       1/11 (9%)       0/12 (0%)      |     0/9 (0%)        1/12 (8%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             826             819           |      749             911 (T)         869           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.319         P=0.204         P=0.471        |     P=0.628N        P=0.719N        P=0.752N       |
|INCIDENTAL TUMOR       |     P=0.338         P=0.235         P=0.492        |     P=0.625N        P=0.736N        P=0.755N       |
|LOGISTIC REGRESSION    |     P=0.322         P=0.212         P=0.486        |     P=0.636         P=0.747N        P=0.759        |
|COCHRAN-ARMITAGE       |     P=0.360                                        |     P=0.640                                        |
|FISHER EXACT           |                     P=0.247         P=0.500        |                     P=0.753N        P=0.753N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     6/50 (12%)      7/50 (14%)      5/50 (10%)     |     5/50 (10%)      5/50 (10%)      3/50 (6%)      |
|ADJUSTED (b)           |     24.9%           29.4%           29.3%          |     14.6%           30.2%           17.1%          |
|TERMINAL (d)           |     2/14 (14%)      1/11 (9%)       1/12 (8%)      |     0/9 (0%)        3/12 (25%)      1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      482             616             819           |      521             621             530           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.555         P=0.412         P=0.607N       |     P=0.289N        P=0.526N        P=0.382N       |
|INCIDENTAL TUMOR       |     P=0.456N        P=0.555         P=0.589N       |     P=0.330N        P=0.624         P=0.408N       |
|LOGISTIC REGRESSION    |     P=0.472N        P=0.508         P=0.547N       |     P=0.297N        P=0.629         P=0.352N       |
|COCHRAN-ARMITAGE       |     P=0.439N                                       |     P=0.297N                                       |
|FISHER EXACT           |                     P=0.500         P=0.500N       |                     P=0.630N        P=0.357N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   5
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/49 (0%)       1/50 (2%)       0/50 (0%)      |     0/49 (0%)       1/50 (2%)       2/50 (4%)      |
|ADJUSTED (b)           |      0.0%            2.1%            0.0%          |      0.0%            3.4%           11.3%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             568             ---           |      ---             805             741           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.727N        P=0.522           (e)          |     P=0.140         P=0.530         P=0.254        |
|INCIDENTAL TUMOR       |     P=0.519N        P=0.638           (e)          |     P=0.154         P=0.494         P=0.252        |
|LOGISTIC REGRESSION    |     P=0.723N        P=0.436           (e)          |     P=0.139         P=0.510         P=0.236        |
|COCHRAN-ARMITAGE       |     P=0.728N                                       |     P=0.145                                        |
|FISHER EXACT           |                     P=0.505           (e)          |                     P=0.505         P=0.253        |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Adenoma                                                                                                      |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    13/49 (27%)     18/50 (36%)     12/50 (24%)     |    13/49 (27%)     16/50 (32%)     13/50 (26%)     |
|ADJUSTED (b)           |     64.8%           72.2%           55.2%          |     50.9%           62.4%           69.3%          |
|TERMINAL (d)           |     8/14 (57%)      6/11 (55%)      4/12 (33%)     |     2/9 (22%)       4/12 (33%)      6/10 (60%)     |
|FIRST INCIDENCE (DAYS) |      605             386             469           |      527             616             416           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.438         P=0.095         P=0.515        |     P=0.516N        P=0.565         P=0.580N       |
|INCIDENTAL TUMOR       |     P=0.483N        P=0.200         P=0.580N       |     P=0.504N        P=0.373         P=0.559N       |
|LOGISTIC REGRESSION    |     P=0.530N        P=0.196         P=0.578        |     P=0.542N        P=0.413         P=0.577N       |
|COCHRAN-ARMITAGE       |     P=0.431N                                       |     P=0.519N                                       |
|FISHER EXACT           |                     P=0.212         P=0.477N       |                     P=0.353         P=0.567N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   6
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma                                                                                                    |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    20/49 (41%)     17/50 (34%)     21/50 (42%)     |    19/49 (39%)     18/50 (36%)      8/50 (16%)     |
|ADJUSTED (b)           |     57.4%           52.3%           57.1%          |     69.2%           68.2%           42.4%          |
|TERMINAL (d)           |     2/14 (14%)      2/11 (18%)      2/12 (17%)     |     3/9 (33%)       6/12 (50%)      3/10 (30%)     |
|FIRST INCIDENCE (DAYS) |      328             446             297           |      547             691             651           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.302         P=0.480N        P=0.335        |     P=0.018N*       P=0.264N        P=0.021N*      |
|INCIDENTAL TUMOR       |     P=0.481         P=0.341N        P=0.563        |     P=0.005N**      P=0.399N        P=0.007N**     |
|LOGISTIC REGRESSION    |     P=0.528N        P=0.320N        P=0.565N       |     P=0.009N**      P=0.379N        P=0.011N*      |
|COCHRAN-ARMITAGE       |     P=0.491                                        |     P=0.009N**                                     |
|FISHER EXACT           |                     P=0.311N        P=0.534        |                     P=0.469N        P=0.010N**     |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma or Hepatocellular Adenoma                                                                          |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    31/49 (63%)     34/50 (68%)     31/50 (62%)     |    27/49 (55%)     28/50 (56%)     21/50 (42%)     |
|ADJUSTED (b)           |     87.0%           87.1%           81.3%          |     80.9%           85.8%           93.7%          |
|TERMINAL (d)           |    10/14 (71%)      7/11 (64%)      6/12 (50%)     |     4/9 (44%)       8/12 (67%)      9/10 (90%)     |
|FIRST INCIDENCE (DAYS) |      328             386             297           |      527             616             416           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.284         P=0.217         P=0.325        |     P=0.177N        P=0.315N        P=0.200N       |
|INCIDENTAL TUMOR       |     P=0.516N        P=0.346         P=0.561N       |     P=0.084N        P=0.547N        P=0.108N       |
|LOGISTIC REGRESSION    |     P=0.484N        P=0.389         P=0.538N       |     P=0.124N        P=0.508N        P=0.144N       |
|COCHRAN-ARMITAGE       |     P=0.488N                                       |     P=0.113N                                       |
|FISHER EXACT           |                     P=0.388         P=0.531N       |                     P=0.545         P=0.135N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   7
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma, Hepatocellular Adenoma, or Hepatoblastoma                                                         |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    31/49 (63%)     34/50 (68%)     31/50 (62%)     |    27/49 (55%)     28/50 (56%)     21/50 (42%)     |
|ADJUSTED (b)           |     87.0%           87.1%           81.3%          |     80.9%           85.8%           93.7%          |
|TERMINAL (d)           |    10/14 (71%)      7/11 (64%)      6/12 (50%)     |     4/9 (44%)       8/12 (67%)      9/10 (90%)     |
|FIRST INCIDENCE (DAYS) |      328             386             297           |      527             616             416           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.284         P=0.217         P=0.325        |     P=0.177N        P=0.315N        P=0.200N       |
|INCIDENTAL TUMOR       |     P=0.516N        P=0.346         P=0.561N       |     P=0.084N        P=0.547N        P=0.108N       |
|LOGISTIC REGRESSION    |     P=0.484N        P=0.389         P=0.538N       |     P=0.124N        P=0.508N        P=0.144N       |
|COCHRAN-ARMITAGE       |     P=0.488N                                       |     P=0.113N                                       |
|FISHER EXACT           |                     P=0.388         P=0.531N       |                     P=0.545         P=0.135N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocholangiocarcinoma                                                                                                    |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/49 (0%)       0/50 (0%)       2/50 (4%)      |     0/49 (0%)       1/50 (2%)       0/50 (0%)      |
|ADJUSTED (b)           |      0.0%            0.0%            9.4%          |      0.0%            2.0%            0.0%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             ---             730           |      ---             544             ---           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.077           (e)           P=0.195        |     P=0.727N        P=0.521           (e)          |
|INCIDENTAL TUMOR       |     P=0.083           (e)           P=0.229        |     P=0.619         P=0.186           (e)          |
|LOGISTIC REGRESSION    |     P=0.093           (e)           P=0.234        |     P=0.686         P=0.277           (e)          |
|COCHRAN-ARMITAGE       |     P=0.097                                        |     P=0.728N                                       |
|FISHER EXACT           |                       (e)           P=0.253        |                     P=0.505           (e)          |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   8
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Adenoma                                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     8/49 (16%)      8/49 (16%)      9/50 (18%)     |     3/50 (6%)       3/49 (6%)      11/50 (22%)     |
|ADJUSTED (b)           |     33.9%           32.8%           50.6%          |     15.7%            8.9%           56.1%          |
|TERMINAL (d)           |     3/14 (21%)      2/11 (18%)      5/12 (42%)     |     1/9 (11%)       0/12 (0%)       4/10 (40%)     |
|FIRST INCIDENCE (DAYS) |      391             678             620           |      721             616             455           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.332         P=0.518         P=0.389        |     P=0.012 *       P=0.586N        P=0.035 *      |
|INCIDENTAL TUMOR       |     P=0.497         P=0.587N        P=0.596        |     P=0.010 **      P=0.618N        P=0.024 *      |
|LOGISTIC REGRESSION    |     P=0.427         P=0.606N        P=0.473        |     P=0.009 **      P=0.633         P=0.020 *      |
|COCHRAN-ARMITAGE       |     P=0.465                                        |     P=0.009 **                                     |
|FISHER EXACT           |                     P=0.607N        P=0.518        |                     P=0.651         P=0.020 *      |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma                                                                                              |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     8/49 (16%)     15/49 (31%)     18/50 (36%)     |     3/50 (6%)       5/49 (10%)      2/50 (4%)      |
|ADJUSTED (b)           |     42.3%           65.3%           70.9%          |     12.2%           26.4%           13.9%          |
|TERMINAL (d)           |     4/14 (29%)      5/11 (45%)      6/12 (50%)     |     0/9 (0%)        2/12 (17%)      1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      805             693             609           |      521             721             833           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.007 **      P=0.033 *       P=0.009 **     |     P=0.395N        P=0.494         P=0.473N       |
|INCIDENTAL TUMOR       |     P=0.011 *       P=0.075         P=0.019 *      |     P=0.468N        P=0.191         P=0.577N       |
|LOGISTIC REGRESSION    |     P=0.005 **      P=0.050         P=0.007 **     |     P=0.423N        P=0.328         P=0.496N       |
|COCHRAN-ARMITAGE       |     P=0.019 *                                      |     P=0.421N                                       |
|FISHER EXACT           |                     P=0.076         P=0.022 *      |                     P=0.346         P=0.500N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE   9
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma                                                              |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    16/49 (33%)     22/49 (45%)     21/50 (42%)     |     6/50 (12%)      8/49 (16%)     12/50 (24%)     |
|ADJUSTED (b)           |     66.0%           76.3%           77.0%          |     26.0%           33.1%           58.0%          |
|TERMINAL (d)           |     7/14 (50%)      6/11 (55%)      7/12 (58%)     |     1/9 (11%)       2/12 (17%)      4/10 (40%)     |
|FIRST INCIDENCE (DAYS) |      391             678             609           |      521             616             455           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.086         P=0.078         P=0.107        |     P=0.096         P=0.547         P=0.143        |
|INCIDENTAL TUMOR       |     P=0.200         P=0.167         P=0.288        |     P=0.065         P=0.282         P=0.081        |
|LOGISTIC REGRESSION    |     P=0.127         P=0.140         P=0.149        |     P=0.072         P=0.341         P=0.096        |
|COCHRAN-ARMITAGE       |     P=0.200                                        |     P=0.074                                        |
|FISHER EXACT           |                     P=0.150         P=0.226        |                     P=0.371         P=0.096        |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       0/50 (0%)       0/50 (0%)      |     3/50 (6%)       2/50 (4%)       3/50 (6%)      |
|ADJUSTED (b)           |      0.0%            0.0%            0.0%          |     20.5%            7.1%           12.5%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     1/9 (11%)       0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             ---             ---           |      824             785             749           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |       (e)             (e)             (e)          |     P=0.582         P=0.400N        P=0.656N       |
|INCIDENTAL TUMOR       |       (e)             (e)             (e)          |     P=0.570N        P=0.497N        P=0.643N       |
|LOGISTIC REGRESSION    |       (e)             (e)             (e)          |     P=0.580         P=0.452N        P=0.653        |
|COCHRAN-ARMITAGE       |       (e)                                          |     P=0.588N                                       |
|FISHER EXACT           |                       (e)             (e)          |                     P=0.500N        P=0.661N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  10
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       0/50 (0%)       0/50 (0%)      |     4/50 (8%)       2/50 (4%)       3/50 (6%)      |
|ADJUSTED (b)           |      0.0%            0.0%            0.0%          |     22.9%            7.1%           12.5%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     1/9 (11%)       0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             ---             ---           |      775             785             749           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |       (e)             (e)             (e)          |     P=0.437N        P=0.256N        P=0.518N       |
|INCIDENTAL TUMOR       |       (e)             (e)             (e)          |     P=0.398N        P=0.339N        P=0.478N       |
|LOGISTIC REGRESSION    |       (e)             (e)             (e)          |     P=0.424N        P=0.298N        P=0.512N       |
|COCHRAN-ARMITAGE       |       (e)                                          |     P=0.417N                                       |
|FISHER EXACT           |                       (e)             (e)          |                     P=0.339N        P=0.500N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Fibroma, Fibroadenoma, Carcinoma, or Adenoma                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       0/50 (0%)       0/50 (0%)      |     4/50 (8%)       2/50 (4%)       3/50 (6%)      |
|ADJUSTED (b)           |      0.0%            0.0%            0.0%          |     22.9%            7.1%           12.5%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     1/9 (11%)       0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             ---             ---           |      775             785             749           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |       (e)             (e)             (e)          |     P=0.437N        P=0.256N        P=0.518N       |
|INCIDENTAL TUMOR       |       (e)             (e)             (e)          |     P=0.398N        P=0.339N        P=0.478N       |
|LOGISTIC REGRESSION    |       (e)             (e)             (e)          |     P=0.424N        P=0.298N        P=0.512N       |
|COCHRAN-ARMITAGE       |       (e)                                          |     P=0.417N                                       |
|FISHER EXACT           |                       (e)             (e)          |                     P=0.339N        P=0.500N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  11
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Ovary                                                                                                                            |
|     Cystadenoma                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |     4/49 (8%)       2/48 (4%)       2/50 (4%)      |
|ADJUSTED (b)           |                                                    |     13.1%            6.7%           20.0%          |
|TERMINAL (d)           |                                                    |     0/9 (0%)        0/12 (0%)       2/10 (20%)     |
|FIRST INCIDENCE (DAYS) |                                                    |      537             754             911 (T)       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |     P=0.253N        P=0.282N        P=0.337N       |
|INCIDENTAL TUMOR       |                                                    |     P=0.266N        P=0.485N        P=0.346N       |
|LOGISTIC REGRESSION    |                                                    |     P=0.247N        P=0.382N        P=0.331N       |
|COCHRAN-ARMITAGE       |                                                    |     P=0.246N                                       |
|FISHER EXACT           |                                                    |                     P=0.349N        P=0.329N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Ovary                                                                                                                            |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |     1/49 (2%)       0/48 (0%)       2/50 (4%)      |
|ADJUSTED (b)           |                                                    |     10.0%            0.0%           12.3%          |
|TERMINAL (d)           |                                                    |     0/9 (0%)        0/12 (0%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |                                                    |      884             ---             665           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |     P=0.379         P=0.464N        P=0.527        |
|INCIDENTAL TUMOR       |                                                    |     P=0.381         P=0.520N        P=0.526        |
|LOGISTIC REGRESSION    |                                                    |     P=0.359         P=0.459N        P=0.498        |
|COCHRAN-ARMITAGE       |                                                    |     P=0.367                                        |
|FISHER EXACT           |                                                    |                     P=0.505N        P=0.508        |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  12
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/47 (0%)       1/49 (2%)       0/48 (0%)      |    19/48 (40%)     11/48 (23%)     12/49 (24%)     |
|ADJUSTED (b)           |      0.0%            2.4%            0.0%          |     71.7%           50.8%           70.5%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/11 (0%)      |     4/9 (44%)       4/12 (33%)      6/10 (60%)     |
|FIRST INCIDENCE (DAYS) |      ---             651             ---           |      547             691             680           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.723         P=0.510           (e)          |     P=0.077N        P=0.028N*       P=0.110N       |
|INCIDENTAL TUMOR       |     P=0.733N        P=0.551           (e)          |     P=0.041N*       P=0.040N*       P=0.055N       |
|LOGISTIC REGRESSION    |     P=0.721N        P=0.480           (e)          |     P=0.072N        P=0.039N*       P=0.098N       |
|COCHRAN-ARMITAGE       |     P=0.729N                                       |     P=0.064N                                       |
|FISHER EXACT           |                     P=0.510           (e)          |                     P=0.061N        P=0.084N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/47 (0%)       1/49 (2%)       0/48 (0%)      |    19/48 (40%)     12/48 (25%)     12/49 (24%)     |
|ADJUSTED (b)           |      0.0%            2.4%            0.0%          |     71.7%           52.5%           70.5%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/11 (0%)      |     4/9 (44%)       4/12 (33%)      6/10 (60%)     |
|FIRST INCIDENCE (DAYS) |      ---             651             ---           |      547             691             680           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.723         P=0.510           (e)          |     P=0.080N        P=0.045N*       P=0.110N       |
|INCIDENTAL TUMOR       |     P=0.733N        P=0.551           (e)          |     P=0.041N*       P=0.066N        P=0.055N       |
|LOGISTIC REGRESSION    |     P=0.721N        P=0.480           (e)          |     P=0.074N        P=0.063N        P=0.098N       |
|COCHRAN-ARMITAGE       |     P=0.729N                                       |     P=0.065N                                       |
|FISHER EXACT           |                     P=0.510           (e)          |                     P=0.095N        P=0.084N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  13
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Intermedia                                                                                                 |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/47 (4%)       0/49 (0%)       0/48 (0%)      |     1/48 (2%)       0/48 (0%)       3/49 (6%)      |
|ADJUSTED (b)           |      8.2%            0.0%            0.0%          |      4.8%            0.0%           23.8%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/11 (0%)      |     0/9 (0%)        0/12 (0%)       2/10 (20%)     |
|FIRST INCIDENCE (DAYS) |      605             ---             ---           |      840             ---             847           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.115N        P=0.264N        P=0.275N       |     P=0.187         P=0.473N        P=0.339        |
|INCIDENTAL TUMOR       |     P=0.035N*       P=0.143N        P=0.103N       |     P=0.191         P=0.513N        P=0.336        |
|LOGISTIC REGRESSION    |     P=0.091N        P=0.231N        P=0.231N       |     P=0.167         P=0.484N        P=0.302        |
|COCHRAN-ARMITAGE       |     P=0.092N                                       |     P=0.181                                        |
|FISHER EXACT           |                     P=0.237N        P=0.242N       |                     P=0.500N        P=0.316        |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     1/50 (2%)       2/50 (4%)       1/50 (2%)      |     1/50 (2%)       2/50 (4%)       0/50 (0%)      |
|ADJUSTED (b)           |      7.1%            9.9%            5.6%          |      2.3%           10.2%            0.0%          |
|TERMINAL (d)           |     1/14 (7%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        1/12 (8%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      911 (T)         678             828           |      621             571             ---           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.545         P=0.441         P=0.720        |     P=0.342N        P=0.553         P=0.495N       |
|INCIDENTAL TUMOR       |     P=0.602         P=0.520         P=0.739        |     P=0.333N        P=0.694         P=0.500N       |
|LOGISTIC REGRESSION    |     P=0.598         P=0.497         P=0.725        |     P=0.363N        P=0.419         P=0.508N       |
|COCHRAN-ARMITAGE       |     P=0.622N                                       |     P=0.360N                                       |
|FISHER EXACT           |                     P=0.500         P=0.753N       |                     P=0.500         P=0.500N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  14
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Sarcoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       2/50 (4%)       0/50 (0%)      |     2/50 (4%)       2/50 (4%)       6/50 (12%)     |
|ADJUSTED (b)           |      0.0%            9.3%            0.0%          |      6.7%            5.8%           25.9%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      ---             716             ---           |      754             595             455           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.628         P=0.214           (e)          |     P=0.082         P=0.655N        P=0.146        |
|INCIDENTAL TUMOR       |     P=0.667         P=0.285           (e)          |     P=0.073         P=0.652N        P=0.129        |
|LOGISTIC REGRESSION    |     P=0.663         P=0.240           (e)          |     P=0.084         P=0.659         P=0.136        |
|COCHRAN-ARMITAGE       |     P=0.669                                        |     P=0.080                                        |
|FISHER EXACT           |                     P=0.247           (e)          |                     P=0.691N        P=0.134        |
|=================================================================================================================================|
|                                                                                                                                 |
|Spleen                                                                                                                           |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     1/49 (2%)       3/49 (6%)       4/50 (8%)      |     2/49 (4%)       3/50 (6%)       3/50 (6%)      |
|ADJUSTED (b)           |      3.4%           14.5%           18.8%          |      5.5%           15.8%           21.8%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       1/12 (8%)      |     0/9 (0%)        1/12 (8%)       2/10 (20%)     |
|FIRST INCIDENCE (DAYS) |      791             787             677           |      621             571             646           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.096         P=0.262         P=0.144        |     P=0.428         P=0.574         P=0.499        |
|INCIDENTAL TUMOR       |     P=0.112         P=0.369         P=0.161        |     P=0.437         P=0.643         P=0.530        |
|LOGISTIC REGRESSION    |     P=0.121         P=0.301         P=0.170        |     P=0.422         P=0.474         P=0.509        |
|COCHRAN-ARMITAGE       |     P=0.138                                        |     P=0.421                                        |
|FISHER EXACT           |                     P=0.309         P=0.187        |                     P=0.510         P=0.510        |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  15
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Stomach, Forestomach                                                                                                             |
|     Squamous Cell Carcinoma or Papilloma Squamous                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     3/50 (6%)       0/50 (0%)       1/50 (2%)      |     1/50 (2%)       0/50 (0%)       0/50 (0%)      |
|ADJUSTED (b)           |     13.8%            0.0%            7.1%          |     11.1%            0.0%            0.0%          |
|TERMINAL (d)           |     1/14 (7%)       0/11 (0%)       0/12 (0%)      |     1/9 (11%)       0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      701             ---             875           |      911 (T)         ---             ---           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.237N        P=0.151N        P=0.396N       |     P=0.248N        P=0.443N        P=0.479N       |
|INCIDENTAL TUMOR       |     P=0.186N        P=0.111N        P=0.330N       |     P=0.248N        P=0.443N        P=0.479N       |
|LOGISTIC REGRESSION    |     P=0.194N        P=0.120N        P=0.336N       |     P=0.248N        P=0.443N        P=0.479N       |
|COCHRAN-ARMITAGE       |     P=0.176N                                       |     P=0.269N                                       |
|FISHER EXACT           |                     P=0.121N        P=0.309N       |                     P=0.500N        P=0.500N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Stomach, Forestomach                                                                                                             |
|     Squamous Cell Papilloma                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/50 (4%)       0/50 (0%)       1/50 (2%)      |     1/50 (2%)       0/50 (0%)       0/50 (0%)      |
|ADJUSTED (b)           |     11.4%            0.0%            7.1%          |     11.1%            0.0%            0.0%          |
|TERMINAL (d)           |     1/14 (7%)       0/11 (0%)       0/12 (0%)      |     1/9 (11%)       0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      840             ---             875           |      911 (T)         ---             ---           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.436N        P=0.289N        P=0.590N       |     P=0.248N        P=0.443N        P=0.479N       |
|INCIDENTAL TUMOR       |     P=0.380N        P=0.242N        P=0.527N       |     P=0.248N        P=0.443N        P=0.479N       |
|LOGISTIC REGRESSION    |     P=0.414N        P=0.263N        P=0.567N       |     P=0.248N        P=0.443N        P=0.479N       |
|COCHRAN-ARMITAGE       |     P=0.360N                                       |     P=0.269N                                       |
|FISHER EXACT           |                     P=0.247N        P=0.500N       |                     P=0.500N        P=0.500N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  16
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Testes                                                                                                                           |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/50 (4%)       1/49 (2%)       2/50 (4%)      |                                                    |
|ADJUSTED (b)           |     10.3%            5.6%           12.7%          |                                                    |
|TERMINAL (d)           |     1/14 (7%)       0/11 (0%)       1/12 (8%)      |                                                    |
|FIRST INCIDENCE (DAYS) |      791             845             808           |                                                    |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.538         P=0.554N        P=0.636        |                                                    |
|INCIDENTAL TUMOR       |     P=0.579         P=0.487N        P=0.659        |                                                    |
|LOGISTIC REGRESSION    |     P=0.559         P=0.521N        P=0.646        |                                                    |
|COCHRAN-ARMITAGE       |     P=0.609                                        |                                                    |
|FISHER EXACT           |                     P=0.508N        P=0.691N       |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: Follicular Cell                                                                                                   |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     1/49 (2%)       0/48 (0%)       0/50 (0%)      |     2/49 (4%)       1/49 (2%)       1/50 (2%)      |
|ADJUSTED (b)           |      6.7%            0.0%            0.0%          |      5.2%            8.3%           10.0%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        1/12 (8%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      903             ---             ---           |      721             911 (T)         911 (T)       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.308N        P=0.562N        P=0.545N       |     P=0.388N        P=0.455N        P=0.531N       |
|INCIDENTAL TUMOR       |     P=0.269N        P=0.471N        P=0.508N       |     P=0.352N        P=0.482N        P=0.474N       |
|LOGISTIC REGRESSION    |     P=0.306N        P=0.548N        P=0.549N       |     P=0.377N        P=0.498N        P=0.497N       |
|COCHRAN-ARMITAGE       |     P=0.268N                                       |     P=0.372N                                       |
|FISHER EXACT           |                     P=0.505N        P=0.495N       |                     P=0.500N        P=0.492N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  17
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: Follicular Cell                                                                                                   |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/49 (4%)       0/48 (0%)       0/50 (0%)      |     2/49 (4%)       1/49 (2%)       1/50 (2%)      |
|ADJUSTED (b)           |     11.6%            0.0%            0.0%          |      5.2%            8.3%           10.0%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        1/12 (8%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      869             ---             ---           |      721             911 (T)         911 (T)       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.128N        P=0.302N        P=0.292N       |     P=0.388N        P=0.455N        P=0.531N       |
|INCIDENTAL TUMOR       |     P=0.093N        P=0.207N        P=0.246N       |     P=0.352N        P=0.482N        P=0.474N       |
|LOGISTIC REGRESSION    |     P=0.119N        P=0.272N        P=0.283N       |     P=0.377N        P=0.498N        P=0.497N       |
|COCHRAN-ARMITAGE       |     P=0.095N                                       |     P=0.372N                                       |
|FISHER EXACT           |                     P=0.253N        P=0.242N       |                     P=0.500N        P=0.492N       |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |     1/50 (2%)       0/50 (0%)       2/50 (4%)      |
|ADJUSTED (b)           |                                                    |      2.8%            0.0%           15.3%          |
|TERMINAL (d)           |                                                    |     0/9 (0%)        0/12 (0%)       1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |                                                    |      749             ---             869           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |     P=0.372         P=0.484N        P=0.522        |
|INCIDENTAL TUMOR       |                                                    |     P=0.375         P=0.512N        P=0.519        |
|LOGISTIC REGRESSION    |                                                    |     P=0.352         P=0.519N        P=0.492        |
|COCHRAN-ARMITAGE       |                                                    |     P=0.360                                        |
|FISHER EXACT           |                                                    |                     P=0.500N        P=0.500        |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  18
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Polyp Stromal                                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |     4/50 (8%)       2/50 (4%)       6/50 (12%)     |
|ADJUSTED (b)           |                                                    |     28.6%            6.6%           20.6%          |
|TERMINAL (d)           |                                                    |     2/9 (22%)       0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |                                                    |      805             792             693           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |     P=0.273         P=0.261N        P=0.363        |
|INCIDENTAL TUMOR       |                                                    |     P=0.312         P=0.313N        P=0.398        |
|LOGISTIC REGRESSION    |                                                    |     P=0.283         P=0.293N        P=0.359        |
|COCHRAN-ARMITAGE       |                                                    |     P=0.290                                        |
|FISHER EXACT           |                                                    |                     P=0.339N        P=0.370        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       2/50 (4%)       0/50 (0%)      |     3/50 (6%)       0/50 (0%)       4/50 (8%)      |
|ADJUSTED (b)           |      0.0%           12.0%            0.0%          |     16.3%            0.0%           26.6%          |
|TERMINAL (d)           |     0/14 (0%)       1/11 (9%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       2/10 (20%)     |
|FIRST INCIDENCE (DAYS) |      ---             735             ---           |      749             ---             665           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.631         P=0.207           (e)          |     P=0.430         P=0.104N        P=0.533        |
|INCIDENTAL TUMOR       |     P=0.647         P=0.235           (e)          |     P=0.428         P=0.132N        P=0.528        |
|LOGISTIC REGRESSION    |     P=0.654         P=0.235           (e)          |     P=0.395         P=0.110N        P=0.487        |
|COCHRAN-ARMITAGE       |     P=0.669                                        |     P=0.406                                        |
|FISHER EXACT           |                     P=0.247           (e)          |                     P=0.121N        P=0.500        |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  19
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/50 (4%)       5/50 (10%)      5/50 (10%)     |     2/50 (4%)       7/50 (14%)      5/50 (10%)     |
|ADJUSTED (b)           |     10.3%           18.4%           23.3%          |      5.5%           33.1%           30.6%          |
|TERMINAL (d)           |     1/14 (7%)       0/11 (0%)       1/12 (8%)      |     0/9 (0%)        2/12 (17%)      2/10 (20%)     |
|FIRST INCIDENCE (DAYS) |      791             568             677           |      621             571             646           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.130         P=0.190         P=0.166        |     P=0.215         P=0.158         P=0.229        |
|INCIDENTAL TUMOR       |     P=0.195         P=0.309         P=0.189        |     P=0.212         P=0.130         P=0.239        |
|LOGISTIC REGRESSION    |     P=0.169         P=0.219         P=0.189        |     P=0.187         P=0.086         P=0.214        |
|COCHRAN-ARMITAGE       |     P=0.178                                        |     P=0.195                                        |
|FISHER EXACT           |                     P=0.218         P=0.218        |                     P=0.080         P=0.218        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma or Hemangioma                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/50 (4%)       7/50 (14%)      5/50 (10%)     |     5/50 (10%)      7/50 (14%)      9/50 (18%)     |
|ADJUSTED (b)           |     10.3%           28.2%           23.3%          |     20.9%           33.1%           52.3%          |
|TERMINAL (d)           |     1/14 (7%)       1/11 (9%)       1/12 (8%)      |     0/9 (0%)        2/12 (17%)      4/10 (40%)     |
|FIRST INCIDENCE (DAYS) |      791             568             677           |      621             571             646           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.140         P=0.067         P=0.166        |     P=0.185         P=0.524         P=0.227        |
|INCIDENTAL TUMOR       |     P=0.206         P=0.125         P=0.189        |     P=0.177         P=0.463         P=0.224        |
|LOGISTIC REGRESSION    |     P=0.182         P=0.083         P=0.189        |     P=0.145         P=0.401         P=0.183        |
|COCHRAN-ARMITAGE       |     P=0.195                                        |     P=0.157                                        |
|FISHER EXACT           |                     P=0.080         P=0.218        |                     P=0.380         P=0.194        |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  20
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Histiocytic Sarcoma                                                                                                         |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     1/50 (2%)       1/50 (2%)       1/50 (2%)      |     4/50 (8%)       0/50 (0%)       3/50 (6%)      |
|ADJUSTED (b)           |      3.7%            2.8%            8.3%          |     25.9%            0.0%            8.1%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       1/12 (8%)      |     1/9 (11%)       0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      807             709             911 (T)       |      826             ---             647           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.597         P=0.741         P=0.725        |     P=0.394N        P=0.038N*       P=0.483N       |
|INCIDENTAL TUMOR       |     P=0.620         P=0.715N        P=0.739        |     P=0.390N        P=0.061N        P=0.478N       |
|LOGISTIC REGRESSION    |     P=0.627         P=0.763         P=0.731        |     P=0.407N        P=0.044N*       P=0.504N       |
|COCHRAN-ARMITAGE       |     P=0.640                                        |     P=0.406N                                       |
|FISHER EXACT           |                     P=0.753N        P=0.753N       |                     P=0.059N        P=0.500N       |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Lymphoma And Histiocytic Sarcoma                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     3/50 (6%)       4/50 (8%)       4/50 (8%)      |    17/50 (34%)     12/50 (24%)     16/50 (32%)     |
|ADJUSTED (b)           |     12.7%           16.4%           18.5%          |     60.7%           42.7%           52.2%          |
|TERMINAL (d)           |     1/14 (7%)       1/11 (9%)       1/12 (8%)      |     2/9 (22%)       2/12 (17%)      1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      578             386             623           |      527             616             647           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.367         P=0.455         P=0.440        |     P=0.489N        P=0.117N        P=0.525N       |
|INCIDENTAL TUMOR       |     P=0.494         P=0.511         P=0.651N       |     P=0.428N        P=0.193N        P=0.470N       |
|LOGISTIC REGRESSION    |     P=0.425         P=0.481         P=0.492        |     P=0.455N        P=0.171N        P=0.501N       |
|COCHRAN-ARMITAGE       |     P=0.424                                        |     P=0.457N                                       |
|FISHER EXACT           |                     P=0.500         P=0.500        |                     P=0.189N        P=0.500N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  21
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Lymphoma: Histiocytic, Lymphocytic, Mixed, NOS, or Undifferentiated                                               |
|     Cell Type                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     2/50 (4%)       3/50 (6%)       3/50 (6%)      |    13/50 (26%)     12/50 (24%)     13/50 (26%)     |
|ADJUSTED (b)           |      9.4%           14.0%           11.1%          |     46.2%           42.7%           48.0%          |
|TERMINAL (d)           |     1/14 (7%)       1/11 (9%)       0/12 (0%)      |     1/9 (11%)       2/12 (17%)      1/10 (10%)     |
|FIRST INCIDENCE (DAYS) |      578             386             623           |      527             616             651           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.369         P=0.463         P=0.457        |     P=0.507         P=0.358N        P=0.542        |
|INCIDENTAL TUMOR       |     P=0.507         P=0.475         P=0.663N       |     P=0.526N        P=0.515N        P=0.575N       |
|LOGISTIC REGRESSION    |     P=0.413         P=0.475         P=0.501        |     P=0.547         P=0.501N        P=0.593        |
|COCHRAN-ARMITAGE       |     P=0.412                                        |     P=0.546N                                       |
|FISHER EXACT           |                     P=0.500         P=0.500        |                     P=0.500N        P=0.590N       |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Osteosarcoma                                                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       0/50 (0%)       1/50 (2%)      |     2/50 (4%)       1/50 (2%)       0/50 (0%)      |
|ADJUSTED (b)           |      0.0%            0.0%            3.6%          |      8.1%            3.1%            0.0%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             ---             741           |      403             786             ---           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.249           (e)           P=0.467        |     P=0.149N        P=0.465N        P=0.233N       |
|INCIDENTAL TUMOR       |     P=0.257           (e)           P=0.492        |     P=0.190N        P=0.677N        P=0.291N       |
|LOGISTIC REGRESSION    |     P=0.270           (e)           P=0.500        |     P=0.150N        P=0.604N        P=0.240N       |
|COCHRAN-ARMITAGE       |     P=0.269                                        |     P=0.142N                                       |
|FISHER EXACT           |                       (e)           P=0.500        |                     P=0.500N        P=0.247N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  22
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Osteosarcoma or Osteoma                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |     0/50 (0%)       0/50 (0%)       1/50 (2%)      |     2/50 (4%)       1/50 (2%)       0/50 (0%)      |
|ADJUSTED (b)           |      0.0%            0.0%            3.6%          |      8.1%            3.1%            0.0%          |
|TERMINAL (d)           |     0/14 (0%)       0/11 (0%)       0/12 (0%)      |     0/9 (0%)        0/12 (0%)       0/10 (0%)      |
|FIRST INCIDENCE (DAYS) |      ---             ---             741           |      403             786             ---           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.249           (e)           P=0.467        |     P=0.149N        P=0.465N        P=0.233N       |
|INCIDENTAL TUMOR       |     P=0.257           (e)           P=0.492        |     P=0.190N        P=0.677N        P=0.291N       |
|LOGISTIC REGRESSION    |     P=0.270           (e)           P=0.500        |     P=0.150N        P=0.604N        P=0.240N       |
|COCHRAN-ARMITAGE       |     P=0.269                                        |     P=0.142N                                       |
|FISHER EXACT           |                       (e)           P=0.500        |                     P=0.500N        P=0.247N       |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Benign Tumors                                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    28/50 (56%)     32/50 (64%)     23/50 (46%)     |    39/50 (78%)     32/50 (64%)     35/50 (70%)     |
|ADJUSTED (b)           |     88.8%           86.8%           87.2%          |     94.0%           87.6%          100.0%          |
|TERMINAL (d)           |    11/14 (79%)      7/11 (64%)      9/12 (75%)     |     7/9 (78%)       8/12 (67%)     10/10 (100%)    |
|FIRST INCIDENCE (DAYS) |      391             386             469           |      521             616             416           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.500N        P=0.157         P=0.484N       |     P=0.303N        P=0.055N        P=0.345N       |
|INCIDENTAL TUMOR       |     P=0.180N        P=0.400         P=0.222N       |     P=0.211N        P=0.068N        P=0.241N       |
|LOGISTIC REGRESSION    |     P=0.214N        P=0.311         P=0.268N       |     P=0.229N        P=0.066N        P=0.253N       |
|COCHRAN-ARMITAGE       |     P=0.183N                                       |     P=0.221N                                       |
|FISHER EXACT           |                     P=0.270         P=0.212N       |                     P=0.093N        P=0.247N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  23
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |      CONTROL         0.5 PPM         1.0 PPM       |      CONTROL         0.5 PPM         1.0 PPM       |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Tumors                                                                                                            |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    30/50 (60%)     41/50 (82%)     40/50 (80%)     |    39/50 (78%)     39/50 (78%)     34/50 (68%)     |
|ADJUSTED (b)           |     74.8%           92.6%           88.4%          |     91.6%           94.3%           85.2%          |
|TERMINAL (d)           |     5/14 (36%)      8/11 (73%)      7/12 (58%)     |     6/9 (67%)      10/12 (83%)      5/10 (50%)     |
|FIRST INCIDENCE (DAYS) |      328             386             297           |      403             544             455           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.033 *       P=0.041 *       P=0.043 *      |     P=0.292N        P=0.241N        P=0.320N       |
|INCIDENTAL TUMOR       |     P=0.011 *       P=0.018 *       P=0.027 *      |     P=0.154N        P=0.473         P=0.191N       |
|LOGISTIC REGRESSION    |     P=0.015 *       P=0.013 *       P=0.025 *      |     P=0.151N        P=0.580         P=0.183N       |
|COCHRAN-ARMITAGE       |     P=0.015 *                                      |     P=0.150N                                       |
|FISHER EXACT           |                     P=0.013 *       P=0.024 *      |                     P=0.595N        P=0.184N       |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant and Benign Tumors                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |       #               #               #            |       #               #               #            |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |    43/50 (86%)     50/50 (100%)    42/50 (84%)     |    48/50 (96%)     49/50 (98%)     47/50 (94%)     |
|ADJUSTED (b)           |     93.2%          100.0%           93.0%          |     97.9%          100.0%          100.0%          |
|TERMINAL (d)           |    11/14 (79%)     11/11 (100%)     9/12 (75%)     |     8/9 (89%)      12/12 (100%)    10/10 (100%)    |
|FIRST INCIDENCE (DAYS) |      328             386             297           |      403             544             416           |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |     P=0.276         P=0.099         P=0.331        |     P=0.473N        P=0.232N        P=0.501N       |
|INCIDENTAL TUMOR       |     P=0.430N        P=0.018 *       P=0.505N       |     P=0.413N        P=0.481         P=0.518N       |
|LOGISTIC REGRESSION    |     P=0.287N        P=0.010 **      P=0.503N       |     P=0.399N        P=0.470         P=0.497N       |
|COCHRAN-ARMITAGE       |     P=0.434N                                       |     P=0.399N                                       |
|FISHER EXACT           |                     P=0.006 **      P=0.500N       |                     P=0.500         P=0.500N       |
|=================================================================================================================================|
         DATE: 05/08/95                     EXPERIMENT: 88034 TEST: 06                                                 PAGE  24
                                  STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- 6  OZONE
                                                 TERMINAL SACRIFICE AT 131 WEEKS
                                                                           
 (a)  Number of tumor-bearing animals / number of animals examined at site.
 (b)  Kaplan-Meier estimated lifetime tumor incidence after adjustment for 
      intercurrent mortality.
 (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.  The incidental tumor 
      test regards these lesions as non-fatal.  Logistic regression is an alternative
      method for analyzing the incidence of non-fatal tumors.  The Cochran-Armitage
      and Fisher's 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).