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TDMS Study 05210-04 Pathology Tables

NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: I. I. T. Research Inst                                   ETHYLBENZENE                                     DATE: 04/24/96       
EXPERIMENT: 05210 TEST: 04                                                                                     TIME: 10:49:43       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                   PAGE:       1        
CONT: N01-ES-75193                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 56393        
PATHOLOGIST: TOMLINSON, MIK                                                                                    CAS: 100-41-4        
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
                                                             CORE STUDY                                                             
                                                                                                                                    
               REASONS FOR REMOVAL:    ALL                                                                                          
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
               REMOVAL DATE RANGE:     ALL                                                                                          
                                                                                                                                    
               TREATMENT GROUPS:       INCLUDE ALL                                                                                  
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: I. I. T. Research Inst                                   ETHYLBENZENE                                     DATE: 04/24/96       
EXPERIMENT: 05210 TEST: 04                                                                                     TIME: 10:49:43       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                                        
CONT: N01-ES-75193                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 56393        
PATHOLOGIST: TOMLINSON, MIK                                                                                    CAS: 100-41-4        


                                                    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: I. I. T. Research Inst                                   ETHYLBENZENE                                     DATE: 04/24/96       
EXPERIMENT: 05210 TEST: 04                                                                                     TIME: 10:49:43       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                                        
CONT: N01-ES-75193                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 56393        
PATHOLOGIST: TOMLINSON, MIK                                                                                    CAS: 100-41-4        


                                     SUMMARY OF STATISTICALLY SIGNIFICANT (P<=.05) RESULTS
                                          IN THE ANALYSIS OF THE STUDY OF ETHYLBENZENE
              ====================================================================================================
                                                           MALE MICE
                                                          -------------
                  ORGAN                               MORPHOLOGY
                 -------                             ------------
              Islets, Pancreatic            Carcinoma or Adenoma
              Liver                         Hepatocellular Carcinoma
                                            Hepatocellular Carcinoma or Hepatoblastoma
              Lung                          Alveolar/Bronchiolar Adenoma
                                            Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma
              All Organs                    Benign Tumors
              ====================================================================================================
                                                           FEMALE MICE
                                                          -------------
                  ORGAN                               MORPHOLOGY
                 -------                             ------------
              Harderian Gland               Adenoma
              Liver                         Hepatocellular Adenoma
                                            Hepatocellular Carcinoma
                                            Hepatocellular Carcinoma or Hepatoblastoma
                                            Hepatocellular Carcinoma or Hepatocellular Adenoma
                                            Hepatocellular Carcinoma, Hepatocellular Adenoma, or Hepatoblastoma
              All Organs                    Malignant Tumors
                                            Malignant and Benign Tumors
              ====================================================================================================
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   1
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Medulla                                                                                                                  |
|     Pheochromocytoma: Benign, Complex, Malignant, NOS                                                                           |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/47 (0%)    0/46 (0%)    0/48 (0%)    0/48 (0%)  |  0/47 (0%)    1/50 (2%)    2/50 (4%)    0/49 (0%)  |
|ADJUSTED (b)           |   0.0%         0.0%         0.0%         0.0%      |   0.0%         2.6%         4.6%         0.0%      |
|TERMINAL (d)           |  0/28 (0%)    0/36 (0%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    1/38 (3%)    1/40 (3%)    0/36 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          ---          ---       |   ---          730 (T)      659          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |    (e)          (e)          (e)          (e)      |  P=0.508N     P=0.516      P=0.273        (e)      |
|INCIDENTAL TUMOR       |    (e)          (e)          (e)          (e)      |  P=0.453N     P=0.516      P=0.317        (e)      |
|LOGISTIC REGRESSION    |    (e)          (e)          (e)          (e)      |  P=0.512N     P=0.516      P=0.251        (e)      |
|COCHRAN-ARMITAGE       |    (e)                                             |  P=0.511N                                          |
|FISHER EXACT           |                 (e)          (e)          (e)      |               P=0.515      P=0.263        (e)      |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/50 (2%)    3/50 (6%)    2/50 (4%)    0/50 (0%)  |  0/50 (0%)    0/50 (0%)    1/50 (2%)    3/50 (6%)  |
|ADJUSTED (b)           |   3.6%         8.0%         6.3%         0.0%      |   0.0%         0.0%         2.5%         8.1%      |
|TERMINAL (d)           |  1/28 (4%)    2/36 (6%)    2/32 (6%)    0/30 (0%)  |  0/35 (0%)    0/38 (0%)    1/40 (3%)    3/37 (8%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      709          729 (T)      ---       |   ---          ---          730 (T)      730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.192N     P=0.398      P=0.547      P=0.486N   |  P=0.021 *      (e)        P=0.527      P=0.131    |
|INCIDENTAL TUMOR       |  P=0.153N     P=0.348      P=0.547      P=0.486N   |  P=0.021 *      (e)        P=0.527      P=0.131    |
|LOGISTIC REGRESSION    |  P=0.182N     P=0.375      P=0.547      P=0.486N   |  P=0.021 *      (e)        P=0.527      P=0.131    |
|COCHRAN-ARMITAGE       |  P=0.183N                                          |  P=0.021 *                                         |
|FISHER EXACT           |               P=0.309      P=0.500      P=0.500N   |                 (e)        P=0.500      P=0.121    |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   2
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/50 (2%)    3/50 (6%)    2/50 (4%)    0/50 (0%)  |  1/50 (2%)    0/50 (0%)    1/50 (2%)    3/50 (6%)  |
|ADJUSTED (b)           |   3.6%         8.0%         6.3%         0.0%      |   2.4%         0.0%         2.5%         8.1%      |
|TERMINAL (d)           |  1/28 (4%)    2/36 (6%)    2/32 (6%)    0/30 (0%)  |  0/35 (0%)    0/38 (0%)    1/40 (3%)    3/37 (8%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      709          729 (T)      ---       |   639          ---          730 (T)      730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.192N     P=0.398      P=0.547      P=0.486N   |  P=0.083      P=0.486N     P=0.730N     P=0.330    |
|INCIDENTAL TUMOR       |  P=0.153N     P=0.348      P=0.547      P=0.486N   |  P=0.059      P=0.531N     P=0.527      P=0.248    |
|LOGISTIC REGRESSION    |  P=0.182N     P=0.375      P=0.547      P=0.486N   |  P=0.081      P=0.516N     P=0.761      P=0.310    |
|COCHRAN-ARMITAGE       |  P=0.183N                                          |  P=0.080                                           |
|FISHER EXACT           |               P=0.309      P=0.500      P=0.500N   |               P=0.500N     P=0.753N     P=0.309    |
|=================================================================================================================================|
|                                                                                                                                 |
|Islets, Pancreatic                                                                                                               |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/49 (0%)    0/50 (0%)    0/48 (0%)    2/48 (4%)  |  0/50 (0%)    0/50 (0%)    1/50 (2%)    0/49 (0%)  |
|ADJUSTED (b)           |   0.0%         0.0%         0.0%         6.1%      |   0.0%         0.0%         2.5%         0.0%      |
|TERMINAL (d)           |  0/28 (0%)    0/36 (0%)    0/32 (0%)    1/30 (3%)  |  0/35 (0%)    0/38 (0%)    1/40 (3%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          ---          669       |   ---          ---          730 (T)      ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.038 *      (e)          (e)        P=0.261    |  P=0.786N       (e)        P=0.527        (e)      |
|INCIDENTAL TUMOR       |  P=0.071        (e)          (e)        P=0.335    |  P=0.786N       (e)        P=0.527        (e)      |
|LOGISTIC REGRESSION    |  P=0.040 *      (e)          (e)        P=0.247    |  P=0.786N       (e)        P=0.527        (e)      |
|COCHRAN-ARMITAGE       |  P=0.040 *                                         |  P=0.790N                                          |
|FISHER EXACT           |                 (e)          (e)        P=0.242    |                 (e)        P=0.500        (e)      |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   3
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Adenoma                                                                                                      |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 12/50 (24%)  16/50 (32%)  17/50 (34%)  18/50 (36%) |  6/50 (12%)   9/50 (18%)  12/50 (24%)  16/50 (32%) |
|ADJUSTED (b)           |  37.6%        39.1%        46.7%        55.8%      |  17.1%        22.1%        27.5%        41.8%      |
|TERMINAL (d)           |  9/28 (32%)  12/36 (33%)  13/32 (41%)  16/30 (53%) |  6/35 (17%)   7/38 (18%)   9/40 (23%)  15/37 (41%) |
|FIRST INCIDENCE (DAYS) |   522          360          579          618       |   730 (T)      562          659          614       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.142      P=0.503      P=0.324      P=0.186    |  P=0.013 *    P=0.345      P=0.165      P=0.018 *  |
|INCIDENTAL TUMOR       |  P=0.164      P=0.335      P=0.345      P=0.175    |  P=0.013 *    P=0.322      P=0.179      P=0.014 *  |
|LOGISTIC REGRESSION    |  P=0.182      P=0.322      P=0.329      P=0.189    |  P=0.014 *    P=0.311      P=0.128      P=0.022 *  |
|COCHRAN-ARMITAGE       |  P=0.178                                           |  P=0.011 *                                         |
|FISHER EXACT           |               P=0.252      P=0.189      P=0.138    |               P=0.288      P=0.096      P=0.014 *  |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma                                                                                                    |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 17/50 (34%)   9/50 (18%)  13/50 (26%)  10/50 (20%) |  7/50 (14%)   4/50 (8%)    3/50 (6%)   12/50 (24%) |
|ADJUSTED (b)           |  41.1%        21.5%        28.5%        23.8%      |  17.3%         9.7%         7.5%        28.3%      |
|TERMINAL (d)           |  5/28 (18%)   5/36 (14%)   3/32 (9%)    1/30 (3%)  |  3/35 (9%)    2/38 (5%)    3/40 (8%)    7/37 (19%) |
|FIRST INCIDENCE (DAYS) |   289          514          480          430       |   565          602          730 (T)      612       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.228N     P=0.032N*    P=0.170N     P=0.083N   |  P=0.029 *    P=0.238N     P=0.127N     P=0.205    |
|INCIDENTAL TUMOR       |  P=0.151N     P=0.138N     P=0.267N     P=0.076N   |  P=0.031 *    P=0.296N     P=0.152N     P=0.215    |
|LOGISTIC REGRESSION    |  P=0.196N     P=0.064N     P=0.321N     P=0.091N   |  P=0.022 *    P=0.259N     P=0.150N     P=0.162    |
|COCHRAN-ARMITAGE       |  P=0.200N                                          |  P=0.022 *                                         |
|FISHER EXACT           |               P=0.055N     P=0.257N     P=0.088N   |               P=0.262N     P=0.159N     P=0.154    |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   4
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma or Hepatoblastoma                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 17/50 (34%)  10/50 (20%)  13/50 (26%)  10/50 (20%) |  7/50 (14%)   4/50 (8%)    3/50 (6%)   12/50 (24%) |
|ADJUSTED (b)           |  41.1%        24.1%        28.5%        23.8%      |  17.3%         9.7%         7.5%        28.3%      |
|TERMINAL (d)           |  5/28 (18%)   6/36 (17%)   3/32 (9%)    1/30 (3%)  |  3/35 (9%)    2/38 (5%)    3/40 (8%)    7/37 (19%) |
|FIRST INCIDENCE (DAYS) |   289          514          480          430       |   565          602          730 (T)      612       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.202N     P=0.049N*    P=0.170N     P=0.083N   |  P=0.029 *    P=0.238N     P=0.127N     P=0.205    |
|INCIDENTAL TUMOR       |  P=0.128N     P=0.197N     P=0.267N     P=0.076N   |  P=0.031 *    P=0.296N     P=0.152N     P=0.215    |
|LOGISTIC REGRESSION    |  P=0.167N     P=0.101N     P=0.321N     P=0.091N   |  P=0.022 *    P=0.259N     P=0.150N     P=0.162    |
|COCHRAN-ARMITAGE       |  P=0.173N                                          |  P=0.022 *                                         |
|FISHER EXACT           |               P=0.088N     P=0.257N     P=0.088N   |               P=0.262N     P=0.159N     P=0.154    |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma or Hepatocellular Adenoma                                                                          |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 27/50 (54%)  24/50 (48%)  30/50 (60%)  27/50 (54%) | 13/50 (26%)  12/50 (24%)  15/50 (30%)  25/50 (50%) |
|ADJUSTED (b)           |  63.7%        54.9%        64.6%        66.7%      |  32.8%        28.2%        34.5%        57.9%      |
|TERMINAL (d)           | 13/28 (46%)  17/36 (47%)  16/32 (50%)  17/30 (57%) |  9/35 (26%)   8/38 (21%)  12/40 (30%)  19/37 (51%) |
|FIRST INCIDENCE (DAYS) |   289          360          480          430       |   565          562          659          612       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.413      P=0.127N     P=0.505N     P=0.433N   |  P=0.004 **   P=0.426N     P=0.562      P=0.029 *  |
|INCIDENTAL TUMOR       |  P=0.469      P=0.419N     P=0.475      P=0.545N   |  P=0.003 **   P=0.508N     P=0.537      P=0.020 *  |
|LOGISTIC REGRESSION    |  P=0.465      P=0.321N     P=0.389      P=0.521N   |  P=0.002 **   P=0.478N     P=0.471      P=0.015 *  |
|COCHRAN-ARMITAGE       |  P=0.447                                           |  P=0.002 **                                        |
|FISHER EXACT           |               P=0.345N     P=0.343      P=0.579N   |               P=0.500N     P=0.412      P=0.011 *  |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   5
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma, Hepatocellular Adenoma, or Hepatoblastoma                                                         |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 27/50 (54%)  24/50 (48%)  30/50 (60%)  27/50 (54%) | 13/50 (26%)  12/50 (24%)  15/50 (30%)  25/50 (50%) |
|ADJUSTED (b)           |  63.7%        54.9%        64.6%        66.7%      |  32.8%        28.2%        34.5%        57.9%      |
|TERMINAL (d)           | 13/28 (46%)  17/36 (47%)  16/32 (50%)  17/30 (57%) |  9/35 (26%)   8/38 (21%)  12/40 (30%)  19/37 (51%) |
|FIRST INCIDENCE (DAYS) |   289          360          480          430       |   565          562          659          612       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.413      P=0.127N     P=0.505N     P=0.433N   |  P=0.004 **   P=0.426N     P=0.562      P=0.029 *  |
|INCIDENTAL TUMOR       |  P=0.469      P=0.419N     P=0.475      P=0.545N   |  P=0.003 **   P=0.508N     P=0.537      P=0.020 *  |
|LOGISTIC REGRESSION    |  P=0.465      P=0.321N     P=0.389      P=0.521N   |  P=0.002 **   P=0.478N     P=0.471      P=0.015 *  |
|COCHRAN-ARMITAGE       |  P=0.447                                           |  P=0.002 **                                        |
|FISHER EXACT           |               P=0.345N     P=0.343      P=0.579N   |               P=0.500N     P=0.412      P=0.011 *  |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Adenoma                                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  5/50 (10%)   9/50 (18%)  10/50 (20%)  16/50 (32%) |  4/50 (8%)    4/50 (8%)    5/49 (10%)   8/50 (16%) |
|ADJUSTED (b)           |  15.1%        22.7%        27.4%        47.3%      |  10.9%        10.5%        11.4%        21.6%      |
|TERMINAL (d)           |  2/28 (7%)    6/36 (17%)   6/32 (19%)  13/30 (43%) |  3/35 (9%)    4/38 (11%)   2/40 (5%)    8/37 (22%) |
|FIRST INCIDENCE (DAYS) |   616          531          602          418       |   694          730 (T)      682          730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.005 **   P=0.341      P=0.218      P=0.014 *  |  P=0.106      P=0.598N     P=0.579      P=0.206    |
|INCIDENTAL TUMOR       |  P=0.008 **   P=0.179      P=0.205      P=0.006 ** |  P=0.141      P=0.619N     P=0.642      P=0.222    |
|LOGISTIC REGRESSION    |  P=0.006 **   P=0.234      P=0.193      P=0.009 ** |  P=0.111      P=0.618N     P=0.525      P=0.218    |
|COCHRAN-ARMITAGE       |  P=0.006 **                                        |  P=0.096                                           |
|FISHER EXACT           |               P=0.194      P=0.131      P=0.006 ** |               P=0.643N     P=0.487      P=0.178    |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   6
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma                                                                                              |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  2/50 (4%)    1/50 (2%)    5/50 (10%)   3/50 (6%)  |  0/50 (0%)    2/50 (4%)    0/49 (0%)    0/50 (0%)  |
|ADJUSTED (b)           |   6.2%         2.8%        13.1%         9.6%      |   0.0%         4.7%         0.0%         0.0%      |
|TERMINAL (d)           |  1/28 (4%)    1/36 (3%)    2/32 (6%)    2/30 (7%)  |  0/35 (0%)    1/38 (3%)    0/40 (0%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   610          729 (T)      588          708       |   ---          590          ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.341      P=0.430N     P=0.285      P=0.534    |  P=0.364N     P=0.251        (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.356      P=0.520N     P=0.238      P=0.529    |  P=0.461N     P=0.232        (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.351      P=0.474N     P=0.227      P=0.529    |  P=0.358N     P=0.225        (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.348                                           |  P=0.369N                                          |
|FISHER EXACT           |               P=0.500N     P=0.218      P=0.500    |               P=0.247        (e)          (e)      |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma                                                              |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  7/50 (14%)  10/50 (20%)  15/50 (30%)  19/50 (38%) |  4/50 (8%)    6/50 (12%)   5/49 (10%)   8/50 (16%) |
|ADJUSTED (b)           |  20.6%        25.2%        37.9%        55.0%      |  10.9%        15.0%        11.4%        21.6%      |
|TERMINAL (d)           |  3/28 (11%)   7/36 (19%)   8/32 (25%)  15/30 (50%) |  3/35 (9%)    5/38 (13%)   2/40 (5%)    8/37 (22%) |
|FIRST INCIDENCE (DAYS) |   610          531          588          418       |   694          590          682          730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.004 **   P=0.482      P=0.114      P=0.014 *  |  P=0.184      P=0.419      P=0.579      P=0.206    |
|INCIDENTAL TUMOR       |  P=0.006 **   P=0.272      P=0.078      P=0.006 ** |  P=0.209      P=0.388      P=0.642      P=0.222    |
|LOGISTIC REGRESSION    |  P=0.004 **   P=0.355      P=0.064      P=0.008 ** |  P=0.181      P=0.386      P=0.525      P=0.218    |
|COCHRAN-ARMITAGE       |  P=0.004 **                                        |  P=0.169                                           |
|FISHER EXACT           |               P=0.298      P=0.045 *    P=0.006 ** |               P=0.370      P=0.487      P=0.178    |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   7
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)  |  1/50 (2%)    3/50 (6%)    0/50 (0%)    0/50 (0%)  |
|ADJUSTED (b)           |   0.0%         0.0%         0.0%         0.0%      |   2.9%         7.3%         0.0%         0.0%      |
|TERMINAL (d)           |  0/28 (0%)    0/36 (0%)    0/32 (0%)    0/30 (0%)  |  1/35 (3%)    1/38 (3%)    0/40 (0%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          ---          ---       |   730 (T)      642          ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |    (e)          (e)          (e)          (e)      |  P=0.144N     P=0.336      P=0.473N     P=0.489N   |
|INCIDENTAL TUMOR       |    (e)          (e)          (e)          (e)      |  P=0.164N     P=0.289      P=0.473N     P=0.489N   |
|LOGISTIC REGRESSION    |    (e)          (e)          (e)          (e)      |  P=0.149N     P=0.311      P=0.473N     P=0.489N   |
|COCHRAN-ARMITAGE       |    (e)                                             |  P=0.150N                                          |
|FISHER EXACT           |                 (e)          (e)          (e)      |               P=0.309      P=0.500N     P=0.500N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Ovary                                                                                                                            |
|     Cystadenoma                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |  2/49 (4%)    0/50 (0%)    0/49 (0%)    2/49 (4%)  |
|ADJUSTED (b)           |                                                    |   5.9%         0.0%         0.0%         5.0%      |
|TERMINAL (d)           |                                                    |  2/34 (6%)    0/38 (0%)    0/40 (0%)    1/37 (3%)  |
|FIRST INCIDENCE (DAYS) |                                                    |   730 (T)      ---          ---          712       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |  P=0.396      P=0.214N     P=0.203N     P=0.661N   |
|INCIDENTAL TUMOR       |                                                    |  P=0.424      P=0.214N     P=0.203N     P=0.640N   |
|LOGISTIC REGRESSION    |                                                    |  P=0.396      P=0.214N     P=0.203N     P=0.665N   |
|COCHRAN-ARMITAGE       |                                                    |  P=0.378                                           |
|FISHER EXACT           |                                                    |               P=0.242N     P=0.247N     P=0.691N   |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   8
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/44 (0%)    0/45 (0%)    0/45 (0%)    0/47 (0%)  |  4/48 (8%)    8/49 (16%)   7/47 (15%)   5/49 (10%) |
|ADJUSTED (b)           |   0.0%         0.0%         0.0%         0.0%      |  11.1%        19.8%        17.0%        13.5%      |
|TERMINAL (d)           |  0/27 (0%)    0/35 (0%)    0/30 (0%)    0/30 (0%)  |  3/35 (9%)    6/38 (16%)   5/38 (13%)   5/37 (14%) |
|FIRST INCIDENCE (DAYS) |   ---          ---          ---          ---       |   725          697          659          730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |    (e)          (e)          (e)          (e)      |  P=0.445N     P=0.223      P=0.322      P=0.533    |
|INCIDENTAL TUMOR       |    (e)          (e)          (e)          (e)      |  P=0.357N     P=0.177      P=0.326      P=0.563    |
|LOGISTIC REGRESSION    |    (e)          (e)          (e)          (e)      |  P=0.425N     P=0.203      P=0.276      P=0.542    |
|COCHRAN-ARMITAGE       |    (e)                                             |  P=0.459N                                          |
|FISHER EXACT           |                 (e)          (e)          (e)      |               P=0.188      P=0.249      P=0.513    |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/44 (0%)    0/45 (0%)    1/45 (2%)    0/47 (0%)  |  4/48 (8%)    8/49 (16%)   7/47 (15%)   5/49 (10%) |
|ADJUSTED (b)           |   0.0%         0.0%         2.4%         0.0%      |  11.1%        19.8%        17.0%        13.5%      |
|TERMINAL (d)           |  0/27 (0%)    0/35 (0%)    0/30 (0%)    0/30 (0%)  |  3/35 (9%)    6/38 (16%)   5/38 (13%)   5/37 (14%) |
|FIRST INCIDENCE (DAYS) |   ---          ---          642          ---       |   725          697          659          730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.776N       (e)        P=0.543        (e)      |  P=0.445N     P=0.223      P=0.322      P=0.533    |
|INCIDENTAL TUMOR       |  P=0.781N       (e)        P=0.500        (e)      |  P=0.357N     P=0.177      P=0.326      P=0.563    |
|LOGISTIC REGRESSION    |  P=0.779N       (e)        P=0.485        (e)      |  P=0.425N     P=0.203      P=0.276      P=0.542    |
|COCHRAN-ARMITAGE       |  P=0.777N                                          |  P=0.459N                                          |
|FISHER EXACT           |                 (e)        P=0.506        (e)      |               P=0.188      P=0.249      P=0.513    |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE   9
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibroma, Fibrosarcoma, Sarcoma, Myxoma, Myxosarcoma, or Fibrous Histiocytoma                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/50 (2%)    0/50 (0%)    0/50 (0%)    0/50 (0%)  |  0/50 (0%)    2/50 (4%)    0/50 (0%)    2/50 (4%)  |
|ADJUSTED (b)           |   3.6%         0.0%         0.0%         0.0%      |   0.0%         5.3%         0.0%         5.4%      |
|TERMINAL (d)           |  1/28 (4%)    0/36 (0%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    2/38 (5%)    0/40 (0%)    2/37 (5%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      ---          ---          ---       |   ---          730 (T)      ---          730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.290      P=0.257        (e)        P=0.251    |
|INCIDENTAL TUMOR       |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.290      P=0.257        (e)        P=0.251    |
|LOGISTIC REGRESSION    |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.290      P=0.257        (e)        P=0.251    |
|COCHRAN-ARMITAGE       |  P=0.474N                                          |  P=0.287                                           |
|FISHER EXACT           |               P=0.500N     P=0.500N     P=0.500N   |               P=0.247        (e)        P=0.247    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibrosarcoma                                                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/50 (2%)    0/50 (0%)    0/50 (0%)    0/50 (0%)  |  0/50 (0%)    2/50 (4%)    0/50 (0%)    0/50 (0%)  |
|ADJUSTED (b)           |   3.6%         0.0%         0.0%         0.0%      |   0.0%         5.3%         0.0%         0.0%      |
|TERMINAL (d)           |  1/28 (4%)    0/36 (0%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    2/38 (5%)    0/40 (0%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      ---          ---          ---       |   ---          730 (T)      ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.364N     P=0.257        (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.364N     P=0.257        (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.364N     P=0.257        (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.474N                                          |  P=0.369N                                          |
|FISHER EXACT           |               P=0.500N     P=0.500N     P=0.500N   |               P=0.247        (e)          (e)      |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE  10
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibrosarcoma, Sarcoma, Myxosarcoma, or Fibrous Histiocytoma                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/50 (2%)    0/50 (0%)    0/50 (0%)    0/50 (0%)  |  0/50 (0%)    2/50 (4%)    0/50 (0%)    1/50 (2%)  |
|ADJUSTED (b)           |   3.6%         0.0%         0.0%         0.0%      |   0.0%         5.3%         0.0%         2.7%      |
|TERMINAL (d)           |  1/28 (4%)    0/36 (0%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    2/38 (5%)    0/40 (0%)    1/37 (3%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      ---          ---          ---       |   ---          730 (T)      ---          730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.628      P=0.257        (e)        P=0.511    |
|INCIDENTAL TUMOR       |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.628      P=0.257        (e)        P=0.511    |
|LOGISTIC REGRESSION    |  P=0.481N     P=0.450N     P=0.473N     P=0.486N   |  P=0.628      P=0.257        (e)        P=0.511    |
|COCHRAN-ARMITAGE       |  P=0.474N                                          |  P=0.622                                           |
|FISHER EXACT           |               P=0.500N     P=0.500N     P=0.500N   |               P=0.247        (e)        P=0.500    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/50 (0%)    0/50 (0%)    1/50 (2%)    0/50 (0%)  |  0/50 (0%)    1/50 (2%)    2/50 (4%)    0/50 (0%)  |
|ADJUSTED (b)           |   0.0%         0.0%         3.0%         0.0%      |   0.0%         2.6%         5.0%         0.0%      |
|TERMINAL (d)           |  0/28 (0%)    0/36 (0%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    1/38 (3%)    2/40 (5%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          724          ---       |   ---          730 (T)      730 (T)      ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.795N       (e)        P=0.526        (e)      |  P=0.510N     P=0.516      P=0.268        (e)      |
|INCIDENTAL TUMOR       |  P=0.661N       (e)        P=0.638        (e)      |  P=0.510N     P=0.516      P=0.268        (e)      |
|LOGISTIC REGRESSION    |  P=0.792N       (e)        P=0.533        (e)      |  P=0.510N     P=0.516      P=0.268        (e)      |
|COCHRAN-ARMITAGE       |  P=0.786N                                          |  P=0.515N                                          |
|FISHER EXACT           |                 (e)        P=0.500        (e)      |               P=0.500      P=0.247        (e)      |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE  11
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Stomach, Forestomach                                                                                                             |
|     Squamous Cell Papilloma                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/50 (0%)    1/50 (2%)    0/50 (0%)    0/50 (0%)  |  1/50 (2%)    2/50 (4%)    1/50 (2%)    1/50 (2%)  |
|ADJUSTED (b)           |   0.0%         2.8%         0.0%         0.0%      |   2.8%         4.7%         2.5%         2.7%      |
|TERMINAL (d)           |  0/28 (0%)    1/36 (3%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    1/38 (3%)    1/40 (3%)    1/37 (3%)  |
|FIRST INCIDENCE (DAYS) |   ---          729 (T)      ---          ---       |   725          562          730 (T)      730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.585N     P=0.550        (e)          (e)      |  P=0.530N     P=0.518      P=0.734N     P=0.751N   |
|INCIDENTAL TUMOR       |  P=0.585N     P=0.550        (e)          (e)      |  P=0.551N     P=0.466      P=0.708N     P=0.702N   |
|LOGISTIC REGRESSION    |  P=0.585N     P=0.550        (e)          (e)      |  P=0.535N     P=0.489      P=0.738N     P=0.744N   |
|COCHRAN-ARMITAGE       |  P=0.576N                                          |  P=0.535N                                          |
|FISHER EXACT           |               P=0.500        (e)          (e)      |               P=0.500      P=0.753N     P=0.753N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: Follicular Cell                                                                                                   |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  3/50 (6%)    2/50 (4%)    1/50 (2%)    6/50 (12%) |  5/50 (10%)   6/50 (12%)   3/50 (6%)    4/50 (8%)  |
|ADJUSTED (b)           |  10.7%         5.1%         3.1%        17.8%      |  13.7%        15.2%         7.1%        10.8%      |
|TERMINAL (d)           |  3/28 (11%)   1/36 (3%)    1/32 (3%)    4/30 (13%) |  4/35 (11%)   5/38 (13%)   2/40 (5%)    4/37 (11%) |
|FIRST INCIDENCE (DAYS) |   729 (T)      640          729 (T)      647       |   694          697          682          730 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.069      P=0.390N     P=0.257N     P=0.294    |  P=0.355N     P=0.557      P=0.288N     P=0.462N   |
|INCIDENTAL TUMOR       |  P=0.088      P=0.469N     P=0.257N     P=0.362    |  P=0.301N     P=0.519      P=0.261N     P=0.437N   |
|LOGISTIC REGRESSION    |  P=0.072      P=0.437N     P=0.257N     P=0.278    |  P=0.339N     P=0.532      P=0.320N     P=0.449N   |
|COCHRAN-ARMITAGE       |  P=0.073                                           |  P=0.372N                                          |
|FISHER EXACT           |               P=0.500N     P=0.309N     P=0.243    |               P=0.500      P=0.357N     P=0.500N   |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE  12
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Polyp Stromal                                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |  2/50 (4%)    1/50 (2%)    1/50 (2%)    0/50 (0%)  |
|ADJUSTED (b)           |                                                    |   4.9%         2.6%         2.5%         0.0%      |
|TERMINAL (d)           |                                                    |  1/35 (3%)    1/38 (3%)    1/40 (3%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |                                                    |   565          730 (T)      730 (T)      ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |  P=0.189N     P=0.481N     P=0.469N     P=0.231N   |
|INCIDENTAL TUMOR       |                                                    |  P=0.239N     P=0.499N     P=0.732N     P=0.322N   |
|LOGISTIC REGRESSION    |                                                    |  P=0.194N     P=0.510N     P=0.505N     P=0.232N   |
|COCHRAN-ARMITAGE       |                                                    |  P=0.194N                                          |
|FISHER EXACT           |                                                    |               P=0.500N     P=0.500N     P=0.247N   |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/50 (2%)    0/50 (0%)    2/50 (4%)    0/50 (0%)  |  0/50 (0%)    3/50 (6%)    3/50 (6%)    0/50 (0%)  |
|ADJUSTED (b)           |   3.6%         0.0%         5.7%         0.0%      |   0.0%         7.9%         7.0%         0.0%      |
|TERMINAL (d)           |  1/28 (4%)    0/36 (0%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    3/38 (8%)    2/40 (5%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      ---          691          ---       |   ---          730 (T)      659          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.469N     P=0.450N     P=0.551      P=0.486N   |  P=0.280N     P=0.136      P=0.149        (e)      |
|INCIDENTAL TUMOR       |  P=0.304N     P=0.450N     P=0.675      P=0.486N   |  P=0.256N     P=0.136      P=0.161        (e)      |
|LOGISTIC REGRESSION    |  P=0.453N     P=0.450N     P=0.554      P=0.486N   |  P=0.281N     P=0.136      P=0.123        (e)      |
|COCHRAN-ARMITAGE       |  P=0.455N                                          |  P=0.291N                                          |
|FISHER EXACT           |               P=0.500N     P=0.500      P=0.500N   |               P=0.121      P=0.121        (e)      |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE  13
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/50 (0%)    1/50 (2%)    0/50 (0%)    0/50 (0%)  |  0/50 (0%)    2/50 (4%)    0/50 (0%)    0/50 (0%)  |
|ADJUSTED (b)           |   0.0%         2.8%         0.0%         0.0%      |   0.0%         5.3%         0.0%         0.0%      |
|TERMINAL (d)           |  0/28 (0%)    1/36 (3%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    2/38 (5%)    0/40 (0%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          729 (T)      ---          ---       |   ---          730 (T)      ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.585N     P=0.550        (e)          (e)      |  P=0.364N     P=0.257        (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.585N     P=0.550        (e)          (e)      |  P=0.364N     P=0.257        (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.585N     P=0.550        (e)          (e)      |  P=0.364N     P=0.257        (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.576N                                          |  P=0.369N                                          |
|FISHER EXACT           |               P=0.500        (e)          (e)      |               P=0.247        (e)          (e)      |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma or Hemangioma                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/50 (2%)    1/50 (2%)    2/50 (4%)    0/50 (0%)  |  0/50 (0%)    4/50 (8%)    3/50 (6%)    0/50 (0%)  |
|ADJUSTED (b)           |   3.6%         2.8%         5.7%         0.0%      |   0.0%        10.5%         7.0%         0.0%      |
|TERMINAL (d)           |  1/28 (4%)    1/36 (3%)    0/32 (0%)    0/30 (0%)  |  0/35 (0%)    4/38 (11%)   2/40 (5%)    0/37 (0%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      729 (T)      691          ---       |   ---          730 (T)      659          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.345N     P=0.705N     P=0.551      P=0.486N   |  P=0.212N     P=0.074      P=0.149        (e)      |
|INCIDENTAL TUMOR       |  P=0.220N     P=0.705N     P=0.675      P=0.486N   |  P=0.193N     P=0.074      P=0.161        (e)      |
|LOGISTIC REGRESSION    |  P=0.330N     P=0.705N     P=0.554      P=0.486N   |  P=0.211N     P=0.074      P=0.123        (e)      |
|COCHRAN-ARMITAGE       |  P=0.333N                                          |  P=0.222N                                          |
|FISHER EXACT           |               P=0.753N     P=0.500      P=0.500N   |               P=0.059      P=0.121        (e)      |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE  14
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Lymphoma: Histiocytic, Lymphocytic, Mixed, NOS, or Undifferentiated                                               |
|     Cell Type                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  2/50 (4%)    2/50 (4%)    3/50 (6%)    2/50 (4%)  |  3/50 (6%)    6/50 (12%)   5/50 (10%)   5/50 (10%) |
|ADJUSTED (b)           |   4.8%         4.8%         8.4%         6.5%      |   7.1%        13.4%        10.7%        12.2%      |
|TERMINAL (d)           |  0/28 (0%)    1/36 (3%)    1/32 (3%)    1/30 (3%)  |  1/35 (3%)    2/38 (5%)    1/40 (3%)    3/37 (8%)  |
|FIRST INCIDENCE (DAYS) |   522          514          680          725       |   423          300          437          666       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.608      P=0.655N     P=0.564      P=0.673N   |  P=0.496      P=0.278      P=0.416      P=0.393    |
|INCIDENTAL TUMOR       |  P=0.501N     P=0.698N     P=0.554      P=0.682N   |  P=0.434      P=0.187      P=0.283      P=0.235    |
|LOGISTIC REGRESSION    |  P=0.609N     P=0.629      P=0.474      P=0.691    |  P=0.237      P=0.175      P=0.340      P=0.358    |
|COCHRAN-ARMITAGE       |  P=0.606N                                          |  P=0.469                                           |
|FISHER EXACT           |               P=0.691N     P=0.500      P=0.691N   |               P=0.243      P=0.357      P=0.357    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Benign Tumors                                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 20/50 (40%)  25/50 (50%)  26/50 (52%)  30/50 (60%) | 20/50 (40%)  26/50 (52%)  27/50 (54%)  28/50 (56%) |
|ADJUSTED (b)           |  56.4%        56.4%        68.1%        78.3%      |  50.8%        63.2%        59.9%        71.6%      |
|TERMINAL (d)           | 13/28 (46%)  17/36 (47%)  20/32 (63%)  22/30 (73%) | 16/35 (46%)  23/38 (61%)  22/40 (55%)  26/37 (70%) |
|FIRST INCIDENCE (DAYS) |   522          360          579          418       |   565          562          659          614       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.045 *    P=0.564      P=0.364      P=0.100    |  P=0.163      P=0.260      P=0.284      P=0.122    |
|INCIDENTAL TUMOR       |  P=0.054      P=0.244      P=0.354      P=0.058    |  P=0.172      P=0.200      P=0.180      P=0.088    |
|LOGISTIC REGRESSION    |  P=0.046 *    P=0.304      P=0.341      P=0.053    |  P=0.176      P=0.190      P=0.163      P=0.116    |
|COCHRAN-ARMITAGE       |  P=0.046 *                                         |  P=0.132                                           |
|FISHER EXACT           |               P=0.211      P=0.158      P=0.036 *  |               P=0.158      P=0.115      P=0.080    |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE  15
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      75 PPM       250          750       |   CONTROL      75 PPM       250          750       |
|                       |                             PPM          PPM       |                             PPM          PPM       |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Tumors                                                                                                            |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 21/50 (42%)  15/50 (30%)  21/50 (42%)  16/50 (32%) | 13/50 (26%)  20/50 (40%)   9/50 (18%)  18/50 (36%) |
|ADJUSTED (b)           |  46.4%        35.2%        44.5%        36.4%      |  28.5%        40.5%        19.3%        39.7%      |
|TERMINAL (d)           |  5/28 (18%)   9/36 (25%)   7/32 (22%)   4/30 (13%) |  4/35 (11%)   9/38 (24%)   4/40 (10%)  10/37 (27%) |
|FIRST INCIDENCE (DAYS) |   289          514          480          259       |   423          300          437          568       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.349N     P=0.082N     P=0.381N     P=0.184N   |  P=0.380      P=0.181      P=0.191N     P=0.279    |
|INCIDENTAL TUMOR       |  P=0.207N     P=0.275N     P=0.479      P=0.192N   |  P=0.161      P=0.031 *    P=0.555N     P=0.093    |
|LOGISTIC REGRESSION    |  P=0.287N     P=0.179N     P=0.448      P=0.212N   |  P=0.075      P=0.045 *    P=0.265N     P=0.192    |
|COCHRAN-ARMITAGE       |  P=0.309N                                          |  P=0.322                                           |
|FISHER EXACT           |               P=0.149N     P=0.580N     P=0.204N   |               P=0.101      P=0.235N     P=0.194    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant and Benign Tumors                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 35/50 (70%)  34/50 (68%)  40/50 (80%)  41/50 (82%) | 29/50 (58%)  38/50 (76%)  31/50 (62%)  38/50 (76%) |
|ADJUSTED (b)           |  76.0%        70.8%        80.0%        89.0%      |  62.9%        76.0%        64.5%        80.8%      |
|TERMINAL (d)           | 17/28 (61%)  22/36 (61%)  22/32 (69%)  25/30 (83%) | 18/35 (51%)  26/38 (68%)  23/40 (58%)  28/37 (76%) |
|FIRST INCIDENCE (DAYS) |   289          360          480          259       |   423          300          437          568       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.131      P=0.159N     P=0.549N     P=0.379    |  P=0.229      P=0.187      P=0.466N     P=0.161    |
|INCIDENTAL TUMOR       |  P=0.094      P=0.570N     P=0.276      P=0.186    |  P=0.081      P=0.030 *    P=0.376      P=0.032 *  |
|LOGISTIC REGRESSION    |  P=0.069      P=0.423N     P=0.248      P=0.162    |  P=0.042 *    P=0.041 *    P=0.431      P=0.045 *  |
|COCHRAN-ARMITAGE       |  P=0.063                                           |  P=0.116                                           |
|FISHER EXACT           |               P=0.500N     P=0.178      P=0.121    |               P=0.044 *    P=0.419      P=0.044 *  |
|=================================================================================================================================|
         DATE: 04/24/96                     EXPERIMENT: 05210 TEST: 04                                                 PAGE  16
                                STATISTICAL ANALYSIS OF PRIMARY TUMORS IN MICE(B6C3F1) -- ETHYLBENZENE
                                                 TERMINAL SACRIFICE AT 105 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).