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TDMS Study 05180-07 Pathology Tables

NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: Battelle Northwest                                     GALLIUM ARSENIDE                                   DATE: 03/09/99       
EXPERIMENT: 05180 TEST: 07                                                                                     TIME: 14:25:49       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                   PAGE:       1        
CONT: NO1-ES-25335                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 62033B       
PATHOLOGIST: MILLER, RODNEY                                                                                    CAS: 1303-00-0000    
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
                                                        2 YEAR CHRONIC MICE                                                         
                                                                                                                                    

               REASONS FOR REMOVAL:    ALL                                                                                          
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
               REMOVAL DATE RANGE:     ALL                                                                                          
                                                                                                                                    
               TREATMENT GROUPS:       INCLUDE ALL                                                                                  
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08
LAB: Battelle Northwest                                     GALLIUM ARSENIDE                                   DATE: 03/09/99

EXPERIMENT: 05180 TEST: 07                                                                                     TIME: 14:25:49
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE
CONT: NO1-ES-25335                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 62033B
PATHOLOGIST: MILLER, RODNEY                                                                                    CAS: 1303-00-0000

Mice(B6C3F1)
-----------------------------
FOR ALL DOSES THE TUMOR RATES IN THE FOLLOWING TISSUES/ORGANS ARE
BASED ON NUMBER OF TISSUES EXAMINED.  IN OTHER TISSUES/ORGANS RATES
ARE BASED ON THE NUMBER OF ANIMALS NECROPSIED.
                                                 ---------------
                                                 Adrenal Cortex
                                                 Adrenal Medulla
                                                 Bone Marrow
                                                 Brain
                                                 Heart
                                                 Islets, Pancreatic
                                                 Kidney
                                                 Liver
                                                 Lung
                                                 Ovary
                                                 Pituitary Gland
                                                 Spleen
                                                 Testes
                                                 Thyroid Gland
                                                 Urinary Bladder
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08   
LAB: Battelle Northwest                                     GALLIUM ARSENIDE                                   DATE: 03/09/99     
EXPERIMENT: 05180 TEST: 07                                                                                     TIME: 14:25:49     
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                                      
CONT: NO1-ES-25335                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 62033B     
PATHOLOGIST: MILLER, RODNEY                                                                                    CAS: 1303-00-0000  



SUMMARY OF STATISTICALLY SIGNIFICANT (P<=.05) RESULTS
IN THE ANALYSIS OF                 GALLIUM ARSENIDE
===============================================================

Male Mice
------------
Organ                                 Morphology
-----                                 ----------
Harderian Gland                        Carcinoma or Adenoma
===============================================================
Female Mice
------------
Organ                                  Morphology
-----                                  ----------
Liver                                  Hepatocellular Carcinoma
Stomach, Forestomach                   Squamous Cell Papilloma
Thyroid Gland: Follicular Cell         Carcinoma
                                       Carcinoma or Adenoma
All Organs                             Malignant Lymphoma: Histiocytic, Lymphocytic, Mixed, NOS, or Undifferentiated Cell Type
                                       Malignant and Benign Tumors
===============================================================
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 1
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)        -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Bone Marrow                                                                                                                      |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/49 (0%)    0/50 (0%)    2/50 (4%)    1/48 (2%)   |1/50 (2%)    1/50 (2%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         4.6%         2.2%        |2.2%         2.2%         0.0%         0.0%         |
|TERMINAL (d)       |     0/34 (0%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |1/36 (3%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     ---          ---          502          665         |735 (T)      672          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.212      (e)          P=0.237      P=0.500     |P=0.236N     P=0.759      P=0.530N     P=0.543N     |
|POLY 3             |     P=0.216      (e)          P=0.242      P=0.507     |P=0.220N     P=0.757N     P=0.520N     P=0.513N     |
|POLY 1.5           |     P=0.212      (e)          P=0.243      P=0.505     |P=0.216N     P=0.759N     P=0.513N     P=0.507N     |
|POLY 6             |     P=0.219      (e)          P=0.242      P=0.510     |P=0.224N     P=0.755N     P=0.526N     P=0.519N     |
|LOGISTIC REGRESSION|     P=0.147      (e)          P=0.220      P=0.475     |P=0.214N     P=0.762N     (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.201      (e)          P=0.253      P=0.495     |P=0.208N     P=0.753N     P=0.500N     P=0.500N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     4/50 (8%)    6/50 (12%)   8/50 (16%)   8/50 (16%)  |2/50 (4%)    3/50 (6%)    2/50 (4%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     9.1%         12.9%        17.8%        17.3%       |4.4%         6.6%         4.9%         4.8%         |
|TERMINAL (d)       |     4/35 (11%)   3/38 (8%)    3/34 (9%)    4/34 (12%)  |1/36 (3%)    2/34 (6%)    1/31 (3%)    2/29 (7%)    |
|FIRST INCIDENCE    |     733 (T)      609          548          561         |633          659          643          735 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.139      P=0.429      P=0.176      P=0.179     |P=0.569N     P=0.497      P=0.639      P=0.626      |
|POLY 3             |     P=0.164      P=0.405      P=0.189      P=0.201     |P=0.524N     P=0.504      P=0.658      P=0.668      |
|POLY 1.5           |     P=0.161      P=0.395      P=0.185      P=0.195     |P=0.506N     P=0.500      P=0.670      P=0.679      |
|POLY 6             |     P=0.167      P=0.419      P=0.197      P=0.209     |P=0.543N     P=0.506      P=0.647      P=0.655      |
|LOGISTIC REGRESSION|     P=0.147      P=0.397      P=0.178      P=0.184     |P=0.505N     P=0.500      P=0.693      P=0.680      |
|COCH-ARM / FISHERS |     P=0.149      P=0.370      P=0.178      P=0.178     |P=0.483N     P=0.500      P=0.691N     P=0.691N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 2
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    1/50 (2%)    3/50 (6%)    4/50 (8%)   |3/50 (6%)    1/50 (2%)    1/50 (2%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     2.3%         2.2%         6.9%         8.9%        |6.6%         2.2%         2.5%         0.0%         |
|TERMINAL (d)       |     0/35 (0%)    1/38 (3%)    2/34 (6%)    4/34 (12%)  |2/36 (6%)    1/34 (3%)    1/31 (3%)    0/29 (0%)    |
|FIRST INCIDENCE    |     686          733 (T)      645          733 (T)     |617          735 (T)      735 (T)      ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.056      P=0.746N     P=0.290      P=0.173     |P=0.121N     P=0.320N     P=0.360N     P=0.155N     |
|POLY 3             |     P=0.064      P=0.752N     P=0.299      P=0.185     |P=0.105N     P=0.305N     P=0.345N     P=0.132N     |
|POLY 1.5           |     P=0.065      P=0.754N     P=0.302      P=0.185     |P=0.099N     P=0.306N     P=0.331N     P=0.126N     |
|POLY 6             |     P=0.062      P=0.749N     P=0.294      P=0.183     |P=0.110N     P=0.304N     P=0.358N     P=0.139N     |
|LOGISTIC REGRESSION|     P=0.065      P=0.757N     P=0.303      P=0.186     |P=0.102N     P=0.305N     P=0.328N     P=0.121N     |
|COCH-ARM / FISHERS |     P=0.065      P=0.753N     P=0.309      P=0.181     |P=0.093N     P=0.309N     P=0.309N     P=0.121N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Harderian Gland                                                                                                                  |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     5/50 (10%)   7/50 (14%)   10/50 (20%)  12/50 (24%) |5/50 (10%)   4/50 (8%)    3/50 (6%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     11.4%        15.1%        22.2%        26.0%       |11.0%        8.8%         7.3%         4.8%         |
|TERMINAL (d)       |     4/35 (11%)   4/38 (11%)   5/34 (15%)   8/34 (24%)  |3/36 (8%)    3/34 (9%)    2/31 (7%)    2/29 (7%)    |
|FIRST INCIDENCE    |     686          609          548          561         |617          659          643          735 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.030 *    P=0.443      P=0.129      P=0.057     |P=0.228N     P=0.513N     P=0.441N     P=0.297N     |
|POLY 3             |     P=0.036 *    P=0.416      P=0.138      P=0.063     |P=0.189N     P=0.500N     P=0.417N     P=0.250N     |
|POLY 1.5           |     P=0.035 *    P=0.406      P=0.135      P=0.061     |P=0.173N     P=0.502N     P=0.397N     P=0.235N     |
|POLY 6             |     P=0.036 *    P=0.429      P=0.144      P=0.066     |P=0.207N     P=0.501N     P=0.437N     P=0.268N     |
|LOGISTIC REGRESSION|     P=0.033 *    P=0.408      P=0.131      P=0.060     |P=0.172N     P=0.500N     P=0.377N     P=0.227N     |
|COCH-ARM / FISHERS |     P=0.033 *    P=0.380      P=0.131      P=0.054     |P=0.154N     P=0.500N     P=0.357N     P=0.218N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 3
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Intestine Small: Jejunum                                                                                                         |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    2/50 (4%)    0/50 (0%)    1/50 (2%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|     4.6%         4.3%         0.0%         2.2%        |0.0%         0.0%         0.0%         2.4%         |
|TERMINAL (d)       |     2/35 (6%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     733 (T)      481          ---          710         |---          ---          ---          707          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.272N     P=0.667N     P=0.245N     P=0.497N    |P=0.171      (e)          (e)          P=0.478      |
|POLY 3             |     P=0.270N     P=0.669N     P=0.242N     P=0.491N    |P=0.178      (e)          (e)          P=0.488      |
|POLY 1.5           |     P=0.267N     P=0.676N     P=0.239N     P=0.492N    |P=0.182      (e)          (e)          P=0.493      |
|POLY 6             |     P=0.274N     P=0.659N     P=0.245N     P=0.490N    |P=0.174      (e)          (e)          P=0.482      |
|LOGISTIC REGRESSION|     P=0.275N     P=0.647      (e)          P=0.492N    |P=0.180      (e)          (e)          P=0.492      |
|COCH-ARM / FISHERS |     P=0.263N     P=0.691N     P=0.247N     P=0.500N    |P=0.186      (e)          (e)          P=0.500      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Intestine Small: Site Unspecified                                                                                                |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    2/50 (4%)    0/50 (0%)    1/50 (2%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    1/50 (2%)    |
|POLY-3 ADJUSTED (b)|     4.6%         4.3%         0.0%         2.2%        |0.0%         0.0%         0.0%         2.4%         |
|TERMINAL (d)       |     2/35 (6%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     733 (T)      481          ---          710         |---          ---          ---          707          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.272N     P=0.667N     P=0.245N     P=0.497N    |P=0.171      (e)          (e)          P=0.478      |
|POLY 3             |     P=0.270N     P=0.669N     P=0.242N     P=0.491N    |P=0.178      (e)          (e)          P=0.488      |
|POLY 1.5           |     P=0.267N     P=0.676N     P=0.239N     P=0.492N    |P=0.182      (e)          (e)          P=0.493      |
|POLY 6             |     P=0.274N     P=0.659N     P=0.245N     P=0.490N    |P=0.174      (e)          (e)          P=0.482      |
|LOGISTIC REGRESSION|     P=0.275N     P=0.647      (e)          P=0.492N    |P=0.180      (e)          (e)          P=0.492      |
|COCH-ARM / FISHERS |     P=0.263N     P=0.691N     P=0.247N     P=0.500N    |P=0.186      (e)          (e)          P=0.500      |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 4
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Islets, Pancreatic                                                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/48 (0%)    3/49 (6%)    0/47 (0%)   |1/50 (2%)    0/50 (0%)    0/50 (0%)    0/48 (0%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         7.1%         0.0%        |2.2%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     0/35 (0%)    0/36 (0%)    3/34 (9%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     ---          ---          733 (T)      ---         |707          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.458      (e)          P=0.116      (e)         |P=0.372N     P=0.495N     P=0.527N     P=0.522N     |
|POLY 3             |     P=0.484      (e)          P=0.113      (e)         |P=0.364N     P=0.498N     P=0.520N     P=0.518N     |
|POLY 1.5           |     P=0.478      (e)          P=0.114      (e)         |P=0.361N     P=0.500N     P=0.514N     P=0.514N     |
|POLY 6             |     P=0.488      (e)          P=0.111      (e)         |P=0.367N     P=0.498N     P=0.526N     P=0.523N     |
|LOGISTIC REGRESSION|     (e)          (e)          P=0.116      (e)         |P=0.362N     P=0.500N     P=0.515N     P=0.514N     |
|COCH-ARM / FISHERS |     P=0.458      (e)          P=0.117      (e)         |P=0.356N     P=0.500N     P=0.500N     P=0.510N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    2/50 (4%)    3/50 (6%)    1/50 (2%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     2.3%         4.4%         7.0%         2.2%        |0.0%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     0/35 (0%)    2/38 (5%)    2/34 (6%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     570          733 (T)      692          599         |---          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.576N     P=0.524      P=0.296      P=0.750N    |(e)          (e)          (e)          (e)          |
|POLY 3             |     P=0.553N     P=0.511      P=0.294      P=0.756N    |(e)          (e)          (e)          (e)          |
|POLY 1.5           |     P=0.552N     P=0.509      P=0.300      P=0.756N    |(e)          (e)          (e)          (e)          |
|POLY 6             |     P=0.556N     P=0.514      P=0.288      P=0.756N    |(e)          (e)          (e)          (e)          |
|LOGISTIC REGRESSION|     P=0.561N     P=0.485      P=0.305      P=0.714     |(e)          (e)          (e)          (e)          |
|COCH-ARM / FISHERS |     P=0.558N     P=0.500      P=0.309      P=0.753N    |(e)          (e)          (e)          (e)          |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 5
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Adenoma                                                                                                      |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     16/50 (32%)  18/50 (36%)  19/50 (38%)  17/50 (34%) |11/50 (22%)  10/50 (20%)  12/50 (24%)  10/50 (20%)  |
|POLY-3 ADJUSTED (b)|     35.1%        36.5%        42.4%        37.5%       |24.5%        22.0%        29.3%        23.3%        |
|TERMINAL (d)       |     13/35 (37%)  11/38 (29%)  15/34 (44%)  14/34 (41%) |11/36 (31%)  9/34 (27%)   10/31 (32%)  8/29 (28%)   |
|FIRST INCIDENCE    |     457          473          502          656         |735 (T)      715          629          505          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.409      P=0.525      P=0.313      P=0.477     |P=0.347      P=0.556N     P=0.338      P=0.487      |
|POLY 3             |     P=0.412      P=0.527      P=0.306      P=0.490     |P=0.503      P=0.487N     P=0.400      P=0.547N     |
|POLY 1.5           |     P=0.452      P=0.493      P=0.323      P=0.504     |P=0.537      P=0.497N     P=0.432      P=0.526N     |
|POLY 6             |     P=0.364      P=0.568      P=0.289      P=0.474     |P=0.468      P=0.479N     P=0.375      P=0.569N     |
|LOGISTIC REGRESSION|     P=0.495      P=0.371      P=0.330      P=0.531     |P=0.427      P=0.537N     P=0.337      P=0.592N     |
|COCH-ARM / FISHERS |     P=0.492      P=0.417      P=0.338      P=0.500     |P=0.509N     P=0.500N     P=0.500      P=0.500N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma                                                                                                    |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     13/50 (26%)  9/50 (18%)   12/50 (24%)  17/50 (34%) |12/50 (24%)  11/50 (22%)  4/50 (8%)    8/50 (16%)   |
|POLY-3 ADJUSTED (b)|     29.0%        19.1%        26.9%        35.3%       |26.3%        23.7%        9.7%         18.6%        |
|TERMINAL (d)       |     7/35 (20%)   6/38 (16%)   8/34 (24%)   9/34 (27%)  |8/36 (22%)   5/34 (15%)   2/31 (7%)    2/29 (7%)    |
|FIRST INCIDENCE    |     561          478          573          406         |633          659          629          628          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.085      P=0.191N     P=0.532N     P=0.276     |P=0.225N     P=0.523N     P=0.065N     P=0.388N     |
|POLY 3             |     P=0.108      P=0.195N     P=0.505N     P=0.333     |P=0.140N     P=0.479N     P=0.040N*    P=0.269N     |
|POLY 1.5           |     P=0.103      P=0.204N     P=0.500N     P=0.312     |P=0.124N     P=0.493N     P=0.035N*    P=0.250N     |
|POLY 6             |     P=0.111      P=0.186N     P=0.511N     P=0.350     |P=0.159N     P=0.463N     P=0.046N*    P=0.287N     |
|LOGISTIC REGRESSION|     P=0.088      P=0.224N     P=0.508N     P=0.245     |P=0.130N     P=0.497N     P=0.040N*    P=0.266N     |
|COCH-ARM / FISHERS |     P=0.090      P=0.235N     P=0.500N     P=0.257     |P=0.105N     P=0.500N     P=0.027N*    P=0.227N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 6
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma or Hepatocellular Adenoma                                                                          |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     26/50 (52%)  23/50 (46%)  27/50 (54%)  30/50 (60%) |21/50 (42%)  19/50 (38%)  14/50 (28%)  18/50 (36%)  |
|POLY-3 ADJUSTED (b)|     55.7%        46.6%        58.0%        61.8%       |46.1%        40.8%        33.9%        41.1%        |
|TERMINAL (d)       |     17/35 (49%)  15/38 (40%)  19/34 (56%)  19/34 (56%) |17/36 (47%)  12/34 (35%)  11/31 (36%)  10/29 (35%)  |
|FIRST INCIDENCE    |     457          473          502          406         |633          659          629          505          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.117      P=0.252N     P=0.455      P=0.299     |P=0.507      P=0.478N     P=0.243N     P=0.523      |
|POLY 3             |     P=0.129      P=0.244N     P=0.494      P=0.344     |P=0.357N     P=0.383N     P=0.172N     P=0.395N     |
|POLY 1.5           |     P=0.134      P=0.269N     P=0.502      P=0.332     |P=0.316N     P=0.405N     P=0.146N     P=0.371N     |
|POLY 6             |     P=0.121      P=0.221N     P=0.487      P=0.353     |P=0.401N     P=0.355N     P=0.197N     P=0.417N     |
|LOGISTIC REGRESSION|     P=0.127      P=0.365N     P=0.494      P=0.280     |P=0.401N     P=0.398N     P=0.201N     P=0.440N     |
|COCH-ARM / FISHERS |     P=0.128      P=0.345N     P=0.500      P=0.273     |P=0.268N     P=0.419N     P=0.104N     P=0.341N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocellular Carcinoma, Hepatocellular Adenoma,                                                                           |
|     or Hepatoblastoma                                                                                                           |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     26/50 (52%)  23/50 (46%)  27/50 (54%)  30/50 (60%) |21/50 (42%)  19/50 (38%)  14/50 (28%)  18/50 (36%)  |
|POLY-3 ADJUSTED (b)|     55.7%        46.6%        58.0%        61.8%       |46.1%        40.8%        33.9%        41.1%        |
|TERMINAL (d)       |     17/35 (49%)  15/38 (40%)  19/34 (56%)  19/34 (56%) |17/36 (47%)  12/34 (35%)  11/31 (36%)  10/29 (35%)  |
|FIRST INCIDENCE    |     457          473          502          406         |633          659          629          505          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.117      P=0.252N     P=0.455      P=0.299     |P=0.507      P=0.478N     P=0.243N     P=0.523      |
|POLY 3             |     P=0.129      P=0.244N     P=0.494      P=0.344     |P=0.357N     P=0.383N     P=0.172N     P=0.395N     |
|POLY 1.5           |     P=0.134      P=0.269N     P=0.502      P=0.332     |P=0.316N     P=0.405N     P=0.146N     P=0.371N     |
|POLY 6             |     P=0.121      P=0.221N     P=0.487      P=0.353     |P=0.401N     P=0.355N     P=0.197N     P=0.417N     |
|LOGISTIC REGRESSION|     P=0.127      P=0.365N     P=0.494      P=0.280     |P=0.401N     P=0.398N     P=0.201N     P=0.440N     |
|COCH-ARM / FISHERS |     P=0.128      P=0.345N     P=0.500      P=0.273     |P=0.268N     P=0.419N     P=0.104N     P=0.341N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 7
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Liver                                                                                                                            |
|     Hepatocholangiocarcinoma                                                                                                    |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    2/50 (4%)    0/50 (0%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    1/50 (2%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     0.0%         4.3%         0.0%         0.0%        |0.0%         0.0%         2.4%         4.7%         |
|TERMINAL (d)       |     0/35 (0%)    1/38 (3%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     ---          481          ---          ---         |---          ---          553          490          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.268N     P=0.251      (e)          (e)         |P=0.054      (e)          P=0.487      P=0.219      |
|POLY 3             |     P=0.254N     P=0.251      (e)          (e)         |P=0.055      (e)          P=0.483      P=0.227      |
|POLY 1.5           |     P=0.256N     P=0.247      (e)          (e)         |P=0.057      (e)          P=0.488      P=0.232      |
|POLY 6             |     P=0.253N     P=0.255      (e)          (e)         |P=0.052      (e)          P=0.479      P=0.222      |
|LOGISTIC REGRESSION|     P=0.283N     P=0.176      (e)          (e)         |P=0.059      (e)          P=0.563      P=0.250      |
|COCH-ARM / FISHERS |     P=0.264N     P=0.247      (e)          (e)         |P=0.060      (e)          P=0.500      P=0.247      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Adenoma                                                                                                |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     13/50 (26%)  10/50 (20%)  11/50 (22%)  7/50 (14%)  |6/50 (12%)   4/50 (8%)    1/50 (2%)    3/50 (6%)    |
|POLY-3 ADJUSTED (b)|     29.4%        21.6%        25.6%        15.3%       |13.3%        8.8%         2.5%         7.1%         |
|TERMINAL (d)       |     11/35 (31%)  8/38 (21%)   10/34 (29%)  5/34 (15%)  |4/36 (11%)   4/34 (12%)   1/31 (3%)    2/29 (7%)    |
|FIRST INCIDENCE    |     686          659          729          555         |617          735 (T)      735 (T)      595          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.160N     P=0.244N     P=0.443N     P=0.119N    |P=0.231N     P=0.403N     P=0.089N     P=0.345N     |
|POLY 3             |     P=0.111N     P=0.271N     P=0.437N     P=0.085N    |P=0.179N     P=0.369N     P=0.075N     P=0.273N     |
|POLY 1.5           |     P=0.112N     P=0.283N     P=0.420N     P=0.089N    |P=0.168N     P=0.372N     P=0.068N     P=0.260N     |
|POLY 6             |     P=0.113N     P=0.256N     P=0.458N     P=0.081N    |P=0.191N     P=0.369N     P=0.082N     P=0.288N     |
|LOGISTIC REGRESSION|     P=0.122N     P=0.257N     P=0.460N     P=0.093N    |P=0.184N     P=0.361N     P=0.075N     P=0.258N     |
|COCH-ARM / FISHERS |     P=0.119N     P=0.318N     P=0.408N     P=0.105N    |P=0.154N     P=0.370N     P=0.056N     P=0.243N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 8
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma                                                                                              |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     3/50 (6%)    6/50 (12%)   6/50 (12%)   6/50 (12%)  |1/50 (2%)    0/50 (0%)    3/50 (6%)    3/50 (6%)    |
|POLY-3 ADJUSTED (b)|     6.8%         13.0%        13.6%        13.3%       |2.2%         0.0%         7.3%         6.9%         |
|TERMINAL (d)       |     3/35 (9%)    4/38 (11%)   3/34 (9%)    5/34 (15%)  |1/36 (3%)    0/34 (0%)    2/31 (7%)    1/29 (3%)    |
|FIRST INCIDENCE    |     733 (T)      705          393          699         |735 (T)      ---          659          365          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.254      P=0.294      P=0.234      P=0.230     |P=0.059      P=0.511N     P=0.255      P=0.267      |
|POLY 3             |     P=0.296      P=0.267      P=0.244      P=0.255     |P=0.071      P=0.498N     P=0.273      P=0.295      |
|POLY 1.5           |     P=0.298      P=0.260      P=0.245      P=0.254     |P=0.075      P=0.500N     P=0.283      P=0.301      |
|POLY 6             |     P=0.292      P=0.276      P=0.242      P=0.256     |P=0.066      P=0.497N     P=0.265      P=0.288      |
|LOGISTIC REGRESSION|     P=0.290      P=0.274      P=0.242      P=0.249     |P=0.084      (e)          P=0.268      P=0.331      |
|COCH-ARM / FISHERS |     P=0.289      P=0.243      P=0.243      P=0.243     |P=0.078      P=0.500N     P=0.309      P=0.309      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar                                                                      |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     15/50 (30%)  14/50 (28%)  16/50 (32%)  13/50 (26%) |7/50 (14%)   4/50 (8%)    4/50 (8%)    6/50 (12%)   |
|POLY-3 ADJUSTED (b)|     34.0%        30.2%        36.3%        28.3%       |15.5%        8.8%         9.8%         13.6%        |
|TERMINAL (d)       |     13/35 (37%)  11/38 (29%)  12/34 (35%)  10/34 (29%) |5/36 (14%)   4/34 (12%)   3/31 (10%)   3/29 (10%)   |
|FIRST INCIDENCE    |     686          659          393          555         |617          735 (T)      659          365          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.503N     P=0.395N     P=0.458      P=0.440N    |P=0.426      P=0.294N     P=0.356N     P=0.605      |
|POLY 3             |     P=0.392N     P=0.438N     P=0.498      P=0.362N    |P=0.527      P=0.260N     P=0.322N     P=0.520N     |
|POLY 1.5           |     P=0.394N     P=0.455N     P=0.505      P=0.373N    |P=0.543      P=0.263N     P=0.301N     P=0.509N     |
|POLY 6             |     P=0.395N     P=0.415N     P=0.486      P=0.351N    |P=0.510      P=0.259N     P=0.340N     P=0.535N     |
|LOGISTIC REGRESSION|     P=0.416N     P=0.420N     P=0.466      P=0.380N    |P=0.552      P=0.253N     P=0.322N     P=0.471N     |
|COCH-ARM / FISHERS |     P=0.414N     P=0.500N     P=0.500      P=0.412N    |P=0.558      P=0.262N     P=0.262N     P=0.500N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 9
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |1/50 (2%)    1/50 (2%)    1/50 (2%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |2.2%         2.2%         2.5%         4.7%         |
|TERMINAL (d)       |     0/35 (0%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |1/36 (3%)    0/34 (0%)    1/31 (3%)    1/29 (3%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |735 (T)      715          735 (T)      646          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.286      P=0.757      P=0.728      P=0.447      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.319      P=0.758N     P=0.738      P=0.481      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.330      P=0.760N     P=0.746      P=0.489      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.309      P=0.756N     P=0.731      P=0.472      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.319      P=0.760N     P=0.728      P=0.488      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.344      P=0.753N     P=0.753N     P=0.500      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Mesentery                                                                                                                        |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |0/50 (0%)    0/50 (0%)    1/50 (2%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     4.5%         0.0%         0.0%         0.0%        |0.0%         0.0%         2.4%         0.0%         |
|TERMINAL (d)       |     1/35 (3%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     570          ---          ---          ---         |---          ---          629          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.166N     P=0.226N     P=0.243N     P=0.241N    |P=0.629      (e)          P=0.471      (e)          |
|POLY 3             |     P=0.167N     P=0.230N     P=0.245N     P=0.234N    |P=0.626      (e)          P=0.482      (e)          |
|POLY 1.5           |     P=0.165N     P=0.231N     P=0.241N     P=0.234N    |P=0.637      (e)          P=0.488      (e)          |
|POLY 6             |     P=0.169N     P=0.228N     P=0.249N     P=0.236N    |P=0.613      (e)          P=0.478      (e)          |
|LOGISTIC REGRESSION|     P=0.164N     P=0.257N     P=0.238N     P=0.253N    |P=0.659      (e)          P=0.528      (e)          |
|COCH-ARM / FISHERS |     P=0.160N     P=0.247N     P=0.247N     P=0.247N    |P=0.649      (e)          P=0.500      (e)          |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 10
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Ovary                                                                                                                            |
|     Cystadenoma                                                                                                                 |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |                                                        |2/49 (4%)    1/50 (2%)    1/50 (2%)    3/46 (7%)    |
|POLY-3 ADJUSTED (b)|                                                        |4.4%         2.2%         2.5%         7.6%         |
|TERMINAL (d)       |                                                        |1/36 (3%)    1/34 (3%)    1/31 (3%)    1/28 (4%)    |
|FIRST INCIDENCE    |                                                        |639          735 (T)      735 (T)      505          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |                                                        |P=0.233      P=0.506N     P=0.551N     P=0.435      |
|POLY 3             |                                                        |P=0.245      P=0.499N     P=0.537N     P=0.442      |
|POLY 1.5           |                                                        |P=0.255      P=0.499N     P=0.523N     P=0.452      |
|POLY 6             |                                                        |P=0.236      P=0.499N     P=0.549N     P=0.432      |
|LOGISTIC REGRESSION|                                                        |P=0.292      P=0.493N     P=0.517N     P=0.614      |
|COCH-ARM / FISHERS |                                                        |P=0.269      P=0.492N     P=0.492N     P=0.470      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/48 (0%)    0/48 (0%)    0/47 (0%)    0/47 (0%)   |3/46 (7%)    7/48 (15%)   5/50 (10%)   7/47 (15%)   |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |7.2%         16.1%        12.1%        17.7%        |
|TERMINAL (d)       |     0/34 (0%)    0/36 (0%)    0/33 (0%)    0/34 (0%)   |1/33 (3%)    6/34 (18%)   3/31 (10%)   6/29 (21%)   |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |729          701          483          646          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.170      P=0.167      P=0.310      P=0.109      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.204      P=0.173      P=0.350      P=0.133      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.224      P=0.170      P=0.364      P=0.144      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.186      P=0.178      P=0.339      P=0.124      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.198      P=0.177      P=0.371      P=0.119      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.261      P=0.176      P=0.405      P=0.167      |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 11
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/48 (0%)    0/48 (0%)    0/47 (0%)    0/47 (0%)   |3/46 (7%)    7/48 (15%)   6/50 (12%)   7/47 (15%)   |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |7.2%         16.1%        14.5%        17.7%        |
|TERMINAL (d)       |     0/34 (0%)    0/36 (0%)    0/33 (0%)    0/34 (0%)   |1/33 (3%)    6/34 (18%)   4/31 (13%)   6/29 (21%)   |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |729          701          483          646          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.158      P=0.167      P=0.205      P=0.109      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.189      P=0.173      P=0.235      P=0.133      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.210      P=0.170      P=0.249      P=0.144      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.171      P=0.178      P=0.225      P=0.124      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.183      P=0.177      P=0.247      P=0.119      |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.247      P=0.176      P=0.287      P=0.167      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Intermedia                                                                                                 |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/48 (0%)    0/48 (0%)    0/47 (0%)    0/47 (0%)   |0/46 (0%)    0/48 (0%)    2/50 (4%)    0/47 (0%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |0.0%         0.0%         4.9%         0.0%         |
|TERMINAL (d)       |     0/34 (0%)    0/36 (0%)    0/33 (0%)    0/34 (0%)   |0/33 (0%)    0/34 (0%)    1/31 (3%)    0/29 (0%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |---          ---          659          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.504      (e)          P=0.216      (e)          |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.501      (e)          P=0.232      (e)          |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.518      (e)          P=0.239      (e)          |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.484      (e)          P=0.227      (e)          |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.533      (e)          P=0.243      (e)          |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.539      (e)          P=0.269      (e)          |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 12
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Intermedia                                                                                                 |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/48 (0%)    0/48 (0%)    0/47 (0%)    0/47 (0%)   |0/46 (0%)    0/48 (0%)    2/50 (4%)    0/47 (0%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |0.0%         0.0%         4.8%         0.0%         |
|TERMINAL (d)       |     0/34 (0%)    0/36 (0%)    0/33 (0%)    0/34 (0%)   |0/33 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |---          ---          365          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.524      (e)          P=0.222      (e)          |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.498      (e)          P=0.237      (e)          |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.516      (e)          P=0.242      (e)          |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.480      (e)          P=0.234      (e)          |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.569      (e)          P=0.461      (e)          |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.539      (e)          P=0.269      (e)          |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Intermedia                                                                                                 |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/48 (0%)    0/48 (0%)    0/47 (0%)    0/47 (0%)   |0/46 (0%)    0/48 (0%)    4/50 (8%)    0/47 (0%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |0.0%         0.0%         9.5%         0.0%         |
|TERMINAL (d)       |     0/34 (0%)    0/36 (0%)    0/33 (0%)    0/34 (0%)   |0/33 (0%)    0/34 (0%)    1/31 (3%)    0/29 (0%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |---          ---          365          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.394      (e)          P=0.055      (e)          |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.370      (e)          P=0.061      (e)          |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.394      (e)          P=0.063      (e)          |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.346      (e)          P=0.059      (e)          |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.467      (e)          P=0.116      (e)          |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.427      (e)          P=0.069      (e)          |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 13
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Sarcoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    0/50 (0%)    0/50 (0%)   |4/50 (8%)    4/50 (8%)    2/50 (4%)    4/50 (8%)    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         0.0%         0.0%        |8.7%         8.8%         4.8%         9.2%         |
|TERMINAL (d)       |     0/35 (0%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    4/34 (12%)   0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     ---          ---          ---          ---         |533          735 (T)      365          412          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     (e)          (e)          (e)          (e)         |P=0.540      P=0.627      P=0.396N     P=0.589      |
|POLY 3             |     (e)          (e)          (e)          (e)         |P=0.550N     P=0.636      P=0.385N     P=0.614      |
|POLY 1.5           |     (e)          (e)          (e)          (e)         |P=0.534N     P=0.637      P=0.368N     P=0.627      |
|POLY 6             |     (e)          (e)          (e)          (e)         |P=0.566N     P=0.631      P=0.404N     P=0.600      |
|LOGISTIC REGRESSION|     (e)          (e)          (e)          (e)         |P=0.484N     P=0.643N     P=0.259N     P=0.602N     |
|COCH-ARM / FISHERS |     (e)          (e)          (e)          (e)         |P=0.514N     P=0.643N     P=0.339N     P=0.643N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Spleen                                                                                                                           |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    0/50 (0%)    2/49 (4%)    1/47 (2%)   |0/50 (0%)    2/50 (4%)    2/50 (4%)    0/49 (0%)    |
|POLY-3 ADJUSTED (b)|     4.5%         0.0%         4.6%         2.3%        |0.0%         4.4%         4.9%         0.0%         |
|TERMINAL (d)       |     0/35 (0%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    1/34 (3%)    2/31 (7%)    0/29 (0%)    |
|FIRST INCIDENCE    |     570          ---          502          665         |---          672          735 (T)      ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.605      P=0.230N     P=0.684      P=0.500N    |P=0.482N     P=0.239      P=0.206      (e)          |
|POLY 3             |     P=0.601      P=0.231N     P=0.683      P=0.508N    |P=0.458N     P=0.241      P=0.216      (e)          |
|POLY 1.5           |     P=0.599      P=0.232N     P=0.686      P=0.510N    |P=0.446N     P=0.238      P=0.223      (e)          |
|POLY 6             |     P=0.600      P=0.230N     P=0.679      P=0.507N    |P=0.470N     P=0.243      P=0.209      (e)          |
|LOGISTIC REGRESSION|     P=0.544      P=0.269N     P=0.678      P=0.584N    |P=0.459N     P=0.238      P=0.206      (e)          |
|COCH-ARM / FISHERS |     P=0.592      P=0.247N     P=0.684      P=0.523N    |P=0.430N     P=0.247      P=0.247      (e)          |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 14
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Stomach, Forestomach                                                                                                             |
|     Squamous Cell Papilloma                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    0/50 (0%)    0/50 (0%)    1/50 (2%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    3/50 (6%)    |
|POLY-3 ADJUSTED (b)|     2.3%         0.0%         0.0%         2.2%        |0.0%         0.0%         0.0%         7.1%         |
|TERMINAL (d)       |     1/35 (3%)    0/38 (0%)    0/34 (0%)    1/34 (3%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    3/29 (10%)   |
|FIRST INCIDENCE    |     733 (T)      ---          ---          733 (T)     |---          ---          ---          735 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.520      P=0.484N     P=0.506N     P=0.755     |P=0.007 **   (e)          (e)          P=0.085      |
|POLY 3             |     P=0.530      P=0.491N     P=0.504N     P=0.755N    |P=0.009 **   (e)          (e)          P=0.108      |
|POLY 1.5           |     P=0.532      P=0.493N     P=0.502N     P=0.755N    |P=0.009 **   (e)          (e)          P=0.112      |
|POLY 6             |     P=0.526      P=0.488N     P=0.507N     P=0.755N    |P=0.008 **   (e)          (e)          P=0.102      |
|LOGISTIC REGRESSION|     P=0.520      (e)          (e)          P=0.755     |(e)          (e)          (e)          P=0.085      |
|COCH-ARM / FISHERS |     P=0.536      P=0.500N     P=0.500N     P=0.753N    |P=0.011 *    (e)          (e)          P=0.121      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Testes                                                                                                                           |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     0/50 (0%)    0/50 (0%)    2/50 (4%)    0/50 (0%)   |                                                    |
|POLY-3 ADJUSTED (b)|     0.0%         0.0%         4.7%         0.0%        |                                                    |
|TERMINAL (d)       |     0/35 (0%)    0/38 (0%)    2/34 (6%)    0/34 (0%)   |                                                    |
|FIRST INCIDENCE    |     ---          ---          733 (T)      ---         |                                                    |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.520      (e)          P=0.232      (e)         |                                                    |
|POLY 3             |     P=0.544      (e)          P=0.232      (e)         |                                                    |
|POLY 1.5           |     P=0.544      (e)          P=0.235      (e)         |                                                    |
|POLY 6             |     P=0.542      (e)          P=0.229      (e)         |                                                    |
|LOGISTIC REGRESSION|     (e)          (e)          P=0.232      (e)         |                                                    |
|COCH-ARM / FISHERS |     P=0.536      (e)          P=0.247      (e)         |                                                    |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 15
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: Follicular Cell                                                                                                   |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    1/50 (2%)    0/50 (0%)    0/48 (0%)   |1/50 (2%)    0/50 (0%)    0/50 (0%)    2/49 (4%)    |
|POLY-3 ADJUSTED (b)|     2.3%         2.2%         0.0%         0.0%        |2.2%         0.0%         0.0%         4.9%         |
|TERMINAL (d)       |     1/35 (3%)    1/38 (3%)    0/34 (0%)    0/34 (0%)   |1/36 (3%)    0/34 (0%)    0/31 (0%)    2/28 (7%)    |
|FIRST INCIDENCE    |     733 (T)      733 (T)      ---          ---         |735 (T)      ---          ---          735 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.219N     P=0.743N     P=0.506N     P=0.506N    |P=0.159      P=0.511N     P=0.530N     P=0.412      |
|POLY 3             |     P=0.216N     P=0.751N     P=0.504N     P=0.498N    |P=0.188      P=0.498N     P=0.520N     P=0.470      |
|POLY 1.5           |     P=0.215N     P=0.753N     P=0.502N     P=0.500N    |P=0.195      P=0.500N     P=0.513N     P=0.480      |
|POLY 6             |     P=0.217N     P=0.747N     P=0.507N     P=0.497N    |P=0.182      P=0.497N     P=0.526N     P=0.458      |
|LOGISTIC REGRESSION|     P=0.219N     P=0.743N     (e)          (e)         |P=0.159      (e)          (e)          P=0.412      |
|COCH-ARM / FISHERS |     P=0.213N     P=0.753N     P=0.500N     P=0.510N    |P=0.204      P=0.500N     P=0.500N     P=0.492      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: Follicular Cell                                                                                                   |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    0/50 (0%)    0/50 (0%)    0/48 (0%)   |0/50 (0%)    0/50 (0%)    0/50 (0%)    2/49 (4%)    |
|POLY-3 ADJUSTED (b)|     2.3%         0.0%         0.0%         0.0%        |0.0%         0.0%         0.0%         4.8%         |
|TERMINAL (d)       |     1/35 (3%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/28 (0%)    |
|FIRST INCIDENCE    |     733 (T)      ---          ---          ---         |---          ---          ---          628          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.362N     P=0.484N     P=0.506N     P=0.506N    |P=0.037 *    (e)          (e)          P=0.214      |
|POLY 3             |     P=0.370N     P=0.491N     P=0.504N     P=0.498N    |P=0.037 *    (e)          (e)          P=0.220      |
|POLY 1.5           |     P=0.366N     P=0.493N     P=0.502N     P=0.500N    |P=0.039 *    (e)          (e)          P=0.225      |
|POLY 6             |     P=0.374N     P=0.488N     P=0.507N     P=0.497N    |P=0.036 *    (e)          (e)          P=0.215      |
|LOGISTIC REGRESSION|     P=0.362N     (e)          (e)          (e)         |P=0.042 *    (e)          (e)          P=0.239      |
|COCH-ARM / FISHERS |     P=0.356N     P=0.500N     P=0.500N     P=0.510N    |P=0.042 *    (e)          (e)          P=0.242      |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 16
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: Follicular Cell                                                                                                   |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |                                                        |                                                    |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    1/50 (2%)    0/50 (0%)    0/48 (0%)   |1/50 (2%)    0/50 (0%)    0/50 (0%)    4/49 (8%)    |
|POLY-3 ADJUSTED (b)|     4.6%         2.2%         0.0%         0.0%        |2.2%         0.0%         0.0%         9.6%         |
|TERMINAL (d)       |     2/35 (6%)    1/38 (3%)    0/34 (0%)    0/34 (0%)   |1/36 (3%)    0/34 (0%)    0/31 (0%)    2/28 (7%)    |
|FIRST INCIDENCE    |     733 (T)      733 (T)      ---          ---         |735 (T)      ---          ---          628          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.113N     P=0.471N     P=0.245N     P=0.245N    |P=0.014 *    P=0.511N     P=0.530N     P=0.129      |
|POLY 3             |     P=0.111N     P=0.484N     P=0.242N     P=0.235N    |P=0.016 *    P=0.498N     P=0.520N     P=0.156      |
|POLY 1.5           |     P=0.110N     P=0.488N     P=0.239N     P=0.238N    |P=0.018 *    P=0.500N     P=0.513N     P=0.163      |
|POLY 6             |     P=0.112N     P=0.479N     P=0.245N     P=0.233N    |P=0.015 *    P=0.497N     P=0.526N     P=0.149      |
|LOGISTIC REGRESSION|     P=0.113N     P=0.471N     (e)          (e)         |P=0.018 *    (e)          (e)          P=0.157      |
|COCH-ARM / FISHERS |     P=0.108N     P=0.500N     P=0.247N     P=0.258N    |P=0.021 *    P=0.500N     P=0.500N     P=0.175      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Polyp Stromal                                                                                                               |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |                                                        |1/50 (2%)    2/50 (4%)    2/50 (4%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|                                                        |2.2%         4.4%         4.9%         4.8%         |
|TERMINAL (d)       |                                                        |1/36 (3%)    2/34 (6%)    1/31 (3%)    2/29 (7%)    |
|FIRST INCIDENCE    |                                                        |735 (T)      735 (T)      560          735 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |                                                        |P=0.363      P=0.480      P=0.458      P=0.424      |
|POLY 3             |                                                        |P=0.406      P=0.504      P=0.470      P=0.478      |
|POLY 1.5           |                                                        |P=0.422      P=0.501      P=0.479      P=0.487      |
|POLY 6             |                                                        |P=0.389      P=0.506      P=0.463      P=0.467      |
|LOGISTIC REGRESSION|                                                        |P=0.416      P=0.480      P=0.505      P=0.424      |
|COCH-ARM / FISHERS |                                                        |P=0.442      P=0.500      P=0.500      P=0.500      |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 17
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Sarcoma Stromal or Polyp Stromal                                                                                            |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |                                                        |1/50 (2%)    2/50 (4%)    3/50 (6%)    2/50 (4%)    |
|POLY-3 ADJUSTED (b)|                                                        |2.2%         4.4%         7.2%         4.8%         |
|TERMINAL (d)       |                                                        |1/36 (3%)    2/34 (6%)    1/31 (3%)    2/29 (7%)    |
|FIRST INCIDENCE    |                                                        |735 (T)      735 (T)      560          735 (T)      |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |                                                        |P=0.332      P=0.480      P=0.266      P=0.424      |
|POLY 3             |                                                        |P=0.370      P=0.504      P=0.278      P=0.478      |
|POLY 1.5           |                                                        |P=0.387      P=0.501      P=0.286      P=0.487      |
|POLY 6             |                                                        |P=0.351      P=0.506      P=0.272      P=0.467      |
|LOGISTIC REGRESSION|                                                        |P=0.393      P=0.480      P=0.316      P=0.424      |
|COCH-ARM / FISHERS |                                                        |P=0.409      P=0.500      P=0.309      P=0.500      |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangioma                                                                                                                  |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     2/50 (4%)    1/50 (2%)    0/50 (0%)    0/50 (0%)   |0/50 (0%)    1/50 (2%)    2/50 (4%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     4.5%         2.2%         0.0%         0.0%        |0.0%         2.2%         4.9%         0.0%         |
|TERMINAL (d)       |     1/35 (3%)    1/38 (3%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    1/34 (3%)    2/31 (7%)    0/29 (0%)    |
|FIRST INCIDENCE    |     561          733 (T)      ---          ---         |---          735 (T)      735 (T)      ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.112N     P=0.481N     P=0.248N     P=0.243N    |P=0.644N     P=0.489      P=0.206      (e)          |
|POLY 3             |     P=0.108N     P=0.489N     P=0.245N     P=0.234N    |P=0.613N     P=0.502      P=0.216      (e)          |
|POLY 1.5           |     P=0.107N     P=0.491N     P=0.241N     P=0.234N    |P=0.602N     P=0.500      P=0.223      (e)          |
|POLY 6             |     P=0.110N     P=0.486N     P=0.249N     P=0.236N    |P=0.625N     P=0.503      P=0.209      (e)          |
|LOGISTIC REGRESSION|     P=0.105N     P=0.518N     P=0.239N     P=0.255N    |(e)          P=0.489      P=0.206      (e)          |
|COCH-ARM / FISHERS |     P=0.105N     P=0.500N     P=0.247N     P=0.247N    |P=0.588N     P=0.500      P=0.247      (e)          |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 18
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     3/50 (6%)    2/50 (4%)    6/50 (12%)   3/50 (6%)   |1/50 (2%)    2/50 (4%)    3/50 (6%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     6.7%         4.4%         13.6%        6.6%        |2.2%         4.4%         7.3%         0.0%         |
|TERMINAL (d)       |     1/35 (3%)    2/38 (5%)    2/34 (6%)    1/34 (3%)   |1/36 (3%)    1/34 (3%)    2/31 (7%)    0/29 (0%)    |
|FIRST INCIDENCE    |     570          733 (T)      502          599         |735 (T)      672          629          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.383      P=0.470N     P=0.236      P=0.658N    |P=0.382N     P=0.492      P=0.256      P=0.543N     |
|POLY 3             |     P=0.410      P=0.487N     P=0.236      P=0.651N    |P=0.351N     P=0.505      P=0.273      P=0.513N     |
|POLY 1.5           |     P=0.410      P=0.489N     P=0.240      P=0.652N    |P=0.336N     P=0.502      P=0.283      P=0.507N     |
|POLY 6             |     P=0.408      P=0.485N     P=0.232      P=0.651N    |P=0.368N     P=0.509      P=0.266      P=0.519N     |
|LOGISTIC REGRESSION|     P=0.394      P=0.506N     P=0.242      P=0.638     |P=0.335N     P=0.501      P=0.276      (e)          |
|COCH-ARM / FISHERS |     P=0.403      P=0.500N     P=0.243      P=0.661N    |P=0.318N     P=0.500      P=0.309      P=0.500N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma or Hemangioma                                                                                               |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     5/50 (10%)   3/50 (6%)    6/50 (12%)   3/50 (6%)   |1/50 (2%)    3/50 (6%)    5/50 (10%)   0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     11.1%        6.5%         13.6%        6.6%        |2.2%         6.6%         12.2%        0.0%         |
|TERMINAL (d)       |     2/35 (6%)    3/38 (8%)    2/34 (6%)    1/34 (3%)   |1/36 (3%)    2/34 (6%)    4/31 (13%)   0/29 (0%)    |
|FIRST INCIDENCE    |     561          733 (T)      502          599         |735 (T)      672          629          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.465N     P=0.326N     P=0.478      P=0.362N    |P=0.400N     P=0.296      P=0.074      P=0.543N     |
|POLY 3             |     P=0.436N     P=0.347N     P=0.484      P=0.350N    |P=0.359N     P=0.311      P=0.081      P=0.513N     |
|POLY 1.5           |     P=0.433N     P=0.347N     P=0.493      P=0.348N    |P=0.339N     P=0.307      P=0.088      P=0.507N     |
|POLY 6             |     P=0.440N     P=0.348N     P=0.474      P=0.353N    |P=0.381N     P=0.314      P=0.077      P=0.519N     |
|LOGISTIC REGRESSION|     P=0.445N     P=0.370N     P=0.500      P=0.392N    |P=0.353N     P=0.308      P=0.080      (e)          |
|COCH-ARM / FISHERS |     P=0.436N     P=0.357N     P=0.500      P=0.357N    |P=0.317N     P=0.309      P=0.102      P=0.500N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 19
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Histiocytic Sarcoma                                                                                                         |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     3/50 (6%)    0/50 (0%)    0/50 (0%)    1/50 (2%)   |1/50 (2%)    0/50 (0%)    0/50 (0%)    0/50 (0%)    |
|POLY-3 ADJUSTED (b)|     6.8%         0.0%         0.0%         2.2%        |2.2%         0.0%         0.0%         0.0%         |
|TERMINAL (d)       |     2/35 (6%)    0/38 (0%)    0/34 (0%)    0/34 (0%)   |0/36 (0%)    0/34 (0%)    0/31 (0%)    0/29 (0%)    |
|FIRST INCIDENCE    |     647          ---          ---          716         |439          ---          ---          ---          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.339N     P=0.111N     P=0.132N     P=0.306N    |P=0.356N     P=0.504N     P=0.517N     P=0.504N     |
|POLY 3             |     P=0.339N     P=0.112N     P=0.124N     P=0.298N    |P=0.356N     P=0.501N     P=0.523N     P=0.516N     |
|POLY 1.5           |     P=0.335N     P=0.114N     P=0.121N     P=0.298N    |P=0.354N     P=0.502N     P=0.516N     P=0.509N     |
|POLY 6             |     P=0.345N     P=0.110N     P=0.127N     P=0.300N    |P=0.358N     P=0.501N     P=0.530N     P=0.523N     |
|LOGISTIC REGRESSION|     P=0.326N     P=0.117N     P=0.122N     P=0.299N    |P=0.357N     P=0.427N     P=0.390N     P=0.543N     |
|COCH-ARM / FISHERS |     P=0.327N     P=0.121N     P=0.121N     P=0.309N    |P=0.351N     P=0.500N     P=0.500N     P=0.500N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Lymphoma: Histiocytic, Lymphocytic, Mixed,                                                                        |
|     NOS, or Undifferentiated Cell Type                                                                                          |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     1/50 (2%)    1/50 (2%)    2/50 (4%)    1/50 (2%)   |3/50 (6%)    8/50 (16%)   11/50 (22%)  10/50 (20%)  |
|POLY-3 ADJUSTED (b)|     2.3%         2.2%         4.7%         2.2%        |6.6%         17.2%        26.6%        23.1%        |
|TERMINAL (d)       |     1/35 (3%)    1/38 (3%)    2/34 (6%)    1/34 (3%)   |1/36 (3%)    4/34 (12%)   9/31 (29%)   4/29 (14%)   |
|FIRST INCIDENCE    |     733 (T)      733 (T)      733 (T)      733 (T)     |639          533          581          595          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.543      P=0.743N     P=0.490      P=0.755     |P=0.026 *    P=0.107      P=0.012 *    P=0.026 *    |
|POLY 3             |     P=0.571      P=0.751N     P=0.493      P=0.755N    |P=0.035 *    P=0.105      P=0.011 *    P=0.027 *    |
|POLY 1.5           |     P=0.572      P=0.753N     P=0.497      P=0.755N    |P=0.042 *    P=0.102      P=0.013 *    P=0.030 *    |
|POLY 6             |     P=0.567      P=0.747N     P=0.488      P=0.755N    |P=0.030 *    P=0.108      P=0.009 **   P=0.025 *    |
|LOGISTIC REGRESSION|     P=0.543      P=0.743N     P=0.490      P=0.755     |P=0.046 *    P=0.101      P=0.014 *    P=0.035 *    |
|COCH-ARM / FISHERS |     P=0.569      P=0.753N     P=0.500      P=0.753N    |P=0.056      P=0.100      P=0.020 *    P=0.036 *    |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 20
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Benign Tumors                                                                                                               |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     30/50 (60%)  28/50 (56%)  33/50 (66%)  28/50 (56%) |22/50 (44%)  24/50 (48%)  26/50 (52%)  22/50 (44%)  |
|POLY-3 ADJUSTED (b)|     64.5%        56.1%        71.0%        59.5%       |47.7%        52.4%        60.6%        49.7%        |
|TERMINAL (d)       |     24/35 (69%)  17/38 (45%)  24/34 (71%)  20/34 (59%) |16/36 (44%)  21/34 (62%)  19/31 (61%)  17/29 (59%)  |
|FIRST INCIDENCE    |     457          473          502          555         |617          659          483          505          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.447      P=0.287N     P=0.302      P=0.462N    |P=0.210      P=0.351      P=0.118      P=0.273      |
|POLY 3             |     P=0.509      P=0.262N     P=0.323      P=0.386N    |P=0.461      P=0.404      P=0.154      P=0.510      |
|POLY 1.5           |     P=0.527N     P=0.306N     P=0.334      P=0.384N    |P=0.510      P=0.405      P=0.187      P=0.543      |
|POLY 6             |     P=0.461      P=0.212N     P=0.320      P=0.387N    |P=0.408      P=0.393      P=0.131      P=0.468      |
|LOGISTIC REGRESSION|     P=0.485N     P=0.423N     P=0.320      P=0.373N    |P=0.402      P=0.451      P=0.142      P=0.494      |
|COCH-ARM / FISHERS |     P=0.493N     P=0.420N     P=0.339      P=0.420N    |P=0.507N     P=0.421      P=0.274      P=0.580N     |
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Tumors                                                                                                            |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     23/50 (46%)  20/50 (40%)  26/50 (52%)  29/50 (58%) |26/50 (52%)  23/50 (46%)  26/50 (52%)  26/50 (52%)  |
|POLY-3 ADJUSTED (b)|     50.1%        41.3%        55.3%        59.0%       |53.8%        48.1%        56.9%        54.2%        |
|TERMINAL (d)       |     14/35 (40%)  13/38 (34%)  15/34 (44%)  16/34 (47%) |15/36 (42%)  12/34 (35%)  16/31 (52%)  8/29 (28%)   |
|FIRST INCIDENCE    |     561          478          393          406         |439          533          281          365          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.061      P=0.259N     P=0.324      P=0.205     |P=0.183      P=0.402N     P=0.338      P=0.333      |
|POLY 3             |     P=0.073      P=0.258N     P=0.383      P=0.252     |P=0.380      P=0.362N     P=0.460      P=0.563      |
|POLY 1.5           |     P=0.066      P=0.278N     P=0.375      P=0.225     |P=0.403      P=0.365N     P=0.508      P=0.576      |
|POLY 6             |     P=0.081      P=0.243N     P=0.390      P=0.278     |P=0.357      P=0.358N     P=0.406      P=0.551      |
|LOGISTIC REGRESSION|     P=0.050      P=0.330N     P=0.339      P=0.162     |P=0.437      P=0.344N     P=0.555N     P=0.518N     |
|COCH-ARM / FISHERS |     P=0.051      P=0.343N     P=0.345      P=0.158     |P=0.408      P=0.345N     P=0.579N     P=0.579N     |
|=================================================================================================================================|
       Date:  03/09/99                           EXPERIMENT: 05180 TEST: 07                                            Page 21
                     Statistical Analysis of Primary Tumors in Mice(B6C3F1)       -                  GALLIUM ARSENIDE
                                         Terminal Sacrifice at 105 weeks 
|=================================================================================================================================|
|                   |                                                        |                                                    |
|                   |                              Males                     |                       Females                      |
|Dose               |     CONTROL      0.1          0.5          1.0         |CONTROL      0.1          0.5          1.0          |
|                   |                  MG/M3        MG/M3        MG/M3       |             MG/M3        MG/M3        MG/M3        |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant and Benign Tumors                                                                                                 |
|                                                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES        |     #            #            #            #           |#            #            #            #            |
|-----------        |                                                        |                                                    |
|OVERALL (a)        |     40/50 (80%)  37/50 (74%)  45/50 (90%)  41/50 (82%) |36/50 (72%)  36/50 (72%)  40/50 (80%)  39/50 (78%)  |
|POLY-3 ADJUSTED (b)|     83.9%        74.0%        91.8%        82.0%       |74.3%        75.1%        84.5%        80.3%        |
|TERMINAL (d)       |     28/35 (80%)  25/38 (66%)  30/34 (88%)  25/34 (74%) |24/36 (67%)  24/34 (71%)  26/31 (84%)  20/29 (69%)  |
|FIRST INCIDENCE    |     457          473          393          406         |439          533          281          365          |
|-------------------|                                                        |                                                    |
|STATISTICAL TESTS  |                                                        |                                                    |
|-------------------|                                                        |                                                    |
|LIFE TABLE         |     P=0.196      P=0.205N     P=0.194      P=0.476     |P=0.047 *    P=0.498      P=0.092      P=0.110      |
|POLY 3             |     P=0.300      P=0.171N     P=0.186      P=0.510N    |P=0.202      P=0.555      P=0.158      P=0.320      |
|POLY 1.5           |     P=0.277      P=0.200N     P=0.165      P=0.554N    |P=0.218      P=0.552      P=0.185      P=0.330      |
|POLY 6             |     P=0.323      P=0.149N     P=0.216      P=0.470N    |P=0.185      P=0.560      P=0.131      P=0.311      |
|LOGISTIC REGRESSION|     P=0.211      P=0.288N     P=0.123      P=0.535     |P=0.176      P=0.587      P=0.192      P=0.315      |
|COCH-ARM / FISHERS |     P=0.209      P=0.318N     P=0.131      P=0.500     |P=0.208      P=0.588N     P=0.241      P=0.322      |
|=================================================================================================================================|

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