1978 

National Cancer Institute 

CARCINOGENESIS 

Technical Report Series 

No. 125 

BIOASSAY OF 

DIOXATHION 

FOR POSSIBLE CARCINOGENICITY 

CAS No. 78-34-2 

NCI-CG-TR-125 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE 

Public Health Service 

National Institutes of Health 

BIOASSAY OF
 

DIOXATHION
 

FOR POSSIBLE CARCINOGENICITY
 

Carcinogenesis Testing Program
 

Division of Cancer Cause and Prevention
 

National Cancer Institute
 

National Institutes of Health
 

Bethesda, Maryland 20014
 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
 

Public Health Service
 

National Institutes of Health
 

DHEW Publication No. (NIH) 78-1380 

REPORT ON THE BIDASSAY OF DIOXATHION
 

FOR POSSIBLE CARCINOGENICITY
 

CARCINOGENESIS TESTING PROGRAM
 

DIVISION OF CANCER CAUSE AND PREVENTION
 

NATIONAL CANCER INSTITUTE, NATIONAL INSTITUTES OF HEALTH
 

FOREWORD: This report presents the results of the bioassay of
 

dioxathion conducted for the Carcinogenesis Testing Program, Division
 

of Cancer Cause and Prevention, National Cancer Institute (NCI),
 

National Institutes of Health, Bethesda, Maryland. This is one of a
 

series of experiments designed to determine whether selected chemicals
 

have the capacity to produce cancer in animals. Negative results, in
 

which the test animals do not have a significantly greater incidence
 

of cancer than control animals, do not necessarily mean the test
 

chemical is not a carcinogen because the experiments are conducted
 

under a limited set of circumstances. Positive results demonstrate
 

that the test chemical is carcinogenic for animals under the conditions of the test 'and indicate a potential risk to man. The actual
 

determination of the risk to man from animal carcinogens requires a
 

wider analysis.
 

CONTRIBUTORS: This bioassay of dioxathion was conducted by Hazleton
 

Laboratories America, Inc., Vienna, Virginia, initially under direct
 

contract to the NCI and currently under a subcontract to Tracer Jitco,
 

Inc., prime contractor for the NCI Carcinogenesis Testing Program.
 

The experimental design was determined by the NCI Project Officers, Dr. J. H. Weisburger (1,2) and Dr. E. K. Weisburger (1). The
 

principal investigators for the contract were Dr. M. B. Powers (3),
 

Dr. R. W. Voelker (3), Dr. W. A. Olson (3,4) and Dr. W. M. Weatherholtz (3). Chemical analysis was performed by Dr. C. L. Guyton
 

(3,5) and the analytical results were reviewed by Dr. N. Zimmerman
 

(6); the technical supervisor of animal treatment and observation
 

was Ms. K. J. Petrovics (3).
 

Histopathologic examinations were performed by Dr. R. H. Habermann (3) and reviewed by Dr. R. W. Voelker (3) at the Hazleton Laboratories America, Inc., and the diagnoses included in this report
 

represent the interpretation of these pathologists. Histopathology
 

findings and reports were reviewed by Dr. R. L. Schueler (7).
 

Compilation of individual animal survival, pathology, and summary tables was performed by EG&G Mason Research Institute (8); the
 

statistical analysis was performed by Mr. W. W. Belew (6) and Dr. J.
 

R. Joiner (7), using methods selected for the Carcinogenesis Testing
 

Program by Dr. J. J. Gart (9).
 

iii
 
This report was prepared at METREK, a Division of The MITRE Corporation (6) under the direction of the NCI. Those responsible for
 

this report at METREK are the project coordinator, Dr. L. W. Thomas
 

(6), task leader Dr. M. R. Kornreich (6), senior biologist Ms. P.
 

Walker (6), biochemist Mr. S. C. Drill (6), and technical editor Ms.
 

P. A. Miller (6). The final report was reviewed by members of the
 

participating organizations.
 

The following other scientists at the National Cancer Institute
 

were responsible for evaluating the bioassay experiment, interpreting
 

the results, and reporting the findings: Dr. K. C. Chu (1), Dr. C.
 

Cueto, Jr. (1), Dr. J. F. Douglas (1), Dr. D. G. Goodman (l), Dr. R.
 

A. Griesemer (1), Dr. H. A. Milman (1), Dr. T. W. Orme (1), Dr. R. A.
 

Squire (1,10), Dr. J. M. Ward (l), and Dr. C. E. Whitmire (1).
 

1.	 Carcinogenesis Testing Program, Division of Cancer Cause and
 

Prevention, National Cancer Institute, National Institutes of
 

Health, Bethesda, Maryland.
 

2.	 Now with the Naylor Dana Institute for Disease Prevention, American Health Foundation, Hammon House Road, Valhalla, New York.
 

3.	 Hazleton Laboratories America, Inc., 9200 Leesburg Turnpike,
 

Vienna, Virginia.
 

4.	 Now with the Center for Regulatory Services, 2347 Paddock Lane,
 

Reston, Virginia.
 

5.	 No wit w h Rhodia, Inc., 23 Belmont Drive, Somerset, New Jersey.
 

6.	 Th MITR e E Corporation, METREK Division, 1820 Dolley Madison
 

Boulevard, McLean, Virginia.
 

7.	 Tracer Jitco, Inc., 1776 East Jefferson Street, Rockville,
 

Maryland.
 

8.	 EG&G Mason Research Institute, 1530 East Jefferson Street,
 

Rockville, Maryland.
 

9.	 Mathematical Statistics and Applied Mathematics Section, Biometry
 

Branch, Field Studies and Statistics Program, Division of Cancer
 

Cause and Prevention, National Cancer Institute, National Institutes of Health, Bethesda, Maryland,
 

Iv
 
10.	 Now with the Division,of Comparative Medicine, Johns Hopkins
 

University, School of Medicine, Traylor Building, Baltimore,
 

Maryland.
 

v
 

SUMMARY
 

A bioassay for possible carcinogenicity of technical-grade
 

dioxathion was conducted using Osborne-Mendel rats and B6C3F1 mice.
 

Dioxathion was administered in the feed, at either of two concentrations, to groups of 50 male and 50 female animals of each species.
 

The high and low time-weighted average concentrations were, respectively, 180 and 90 ppm for male rats and 90 and 45 ppm for female
 

rats. The high and low time-weighted average concentrations for male
 

mice were 567 and 284 ppm, respectively, and for female mice were 935
 

and 467 ppm, respectively. After a 78-week period of chemical administration, observation of the rats continued for an additional 33
 

weeks and the mice were observed for an additional 12 to 13 weeks.
 

For rats, 50 animals of each sex were placed on test as controls and
 

fed only the basal diet, while for mice 20 animals of each sex served
 

as controls.
 

In both species adequate numbers of animals survived long enough
 

to be at risk from late-appearing tumors.
 

A variety of neoplasms was observed in treated animals of both
 

species; however, none of the neoplasms observed were either histopathologically unusual or in statistically significant incidences.
 

Under the conditions of this bioassay, dietary administration
 

of dioxathion was not carcinogenic in Osborne-Mendel rats or B6C3F1
 

mice.
 

vii
 

TABLE OF CONTENTS
 

Page
 

I. INTRODUCTION 1
 

II. MATERIALS AND METHODS 4
 

A. Chemicals 4­

B. Dietary Preparation 6
 

C. Animals 6
 

D. Animal Maintenance 1
 

E. Selection of Initial Concentrations 8
 

F. Experimental Design 10
 

G. Clinical and Histopathologic Examinations 13
 

H. Data Recording and Statistical Analyses 15
 

III. CHRONIC TESTING RESULTS: RATS 20
 

A. Body Weights and Clinical Observations 20
 

B. Survival 20
 

C. Pathology 23
 

D. Statistical Analyses of Results f 24
 

IV. CHRONIC TESTING RESULTS: MICE 32
 

A. Body Weights and Clinical Observations 32
 

B. Survival 32
 

C. Pathology 35
 

D. Statistical Analyses of Results 35
 

V. DISCUSSION 40
 

VI. BIBLIOGRAPHY 41
 

APPENDIX A SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

RATS TREATED WITH DIOXATHION A-l
 

APPENDIX B SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

MICE TREATED WITH DIOXATHION B-l
 

APPENDIX C SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN RATS TREATED WITH DIOXATHION C~i
 

APPENDIX D SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN MICE TREATED WITH DIOXATHION D-l
 

ix
 
LIST OF ILLUSTRATIONS 

Figure Number Page 

I CHEMICAL STRUCTURE OF DIOXATHION S 

2 GROWTH CURVES FOR DIOXATHION 

CHRONIC STUDY RATS 21 

SURVIVAL COMPARISONS OF DIOXATHION 

CHRONIC STUDY RATS 

GROWTH CURVES FOR DIOXATHION 

CHRONIC STUDY MICE 3S 

SURVIVAL COMPARISONS OF DIOXATHION 

CHRONIC STUDY MICE 34 

LIST OF TABLES 

Table Number Page 

DESIGN SUMMARY FOR OSBORNE-MENDEL RATS— 

DIOXATHION FEEDING EXPERIMENT 11 

DESIGN SUMMARY FOR B6C3F1 MICE— 

DIOXATHION FEEDING EXPERIMENT 12 

ANALYSES OF THE INCIDENCE OF PRIMARY 

TUMORS AT SPECIFIC SITES IN MALE RATS 

TREATED WITH DIOXATHION 25 

ANALYSES OF THE INCIDENCE OF PRIMARY 

TUMORS AT SPECIFIC SITES IN FEMALE RATS 

TREATED WITH DIOXATHION 

ANALYSES OF THE INCIDENCE OF PRIMARY 

TUMORS AT SPECIFIC SITES IN MALE MICE 

TREATED WITH DIOXATHION 96 

fi ANALYSES OF THE INCIDENCE OF PRIMARY 

TUMORS AT SPECIFIC SITES IN FEMALE MICE 

TREATED WITH DIOXATHION 

SUMMARY OF THE INCIDENCE OF NEOPLASMS 

IN MALE RATS TREATED WITH DIOXATHION A-3 
LIST OF TABLES (Concluded) 

Table Number Page 

A2 SUMMARY OF THE INCIDENCE OF NEOPLASMS

IN FEMALE RATS TREATED WITH DIOXATHION 

 Jl~7 

Bl SUMMARY OF THE INCIDENCE OF NEOPLASMS IN

MALE MICE TREATED WITH DIOXATHION 

 B-3 

B2 SUMMARY OF THE INCIDENCE OF NEOPLASMS IN

FEMALE MICE TREATED WITH DIOXATHION 

 B-6 

Cl SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC

LESIONS IN MALE RATS TREATED WITH 

DIOXATHION 

 C-3 

C2 SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC

LESIONS IN FEMALE RATS TREATED WITH 

DIOXATHION 

 C-8 

Dl SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC

LESIONS IN MALE MICE TREATED WITH 

DIOXATHION 

 D-3 

D2 SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC

LESIONS IN FEMALE MICE TREATED WITH 

DIOXATHION 

 D-6 

I. INTRODUCTION
 

Dioxathion (NCI No. C00395), an organophosphorous insecticide,
 

was selected for bioassay by the National Cancer Institute because
 

of its widespread use on livestock and edible crops, and a lack of
 

adequate chronic toxicity data.
 

The Chemical Abstracts Service (CAS) Ninth Collective Index
 

(1977) name for this compound is phosphorodithioic acid, S,S'-pdioxane-2,3-diyl 0,0,0",0'-tetraethyl ester. It is also called
 

2,3-p-dioxanedithiol S,S-bis(0,0-diethyl phosphorodithioate); phosphorodithioic acid, S,S'-l,4-dioxane-2,3-diyl 0,0,0',0'-tetraethyl
 

ester; and p-dioxane-2,3-dithiol, S,S-diester with 0,0-diethyl phosphorodithioate.
 

Dioxathion is used as a spray to control mites on cotton, grapes,
 

citrus, ornamentals, and certain other fruits including apples, pears,
 

and quinces; and as a spray or dip on cattle, goats, sheep, and hogs
 

for control of ticks, lice, horn flies, and sheep ked (Farm Chemicals
 

Handbook, 1976).
 

Specific production figures for dioxathion are not available;
 

however, one U.S. company reported commercial production (in excess
 

of 1000 pounds or $1000 in value annually) in 1975 (U.S. International
 

Trade Commission, 1977).
 

*
 

The CAS registry number is 78-34-2.
 
The potential for exposure to dioxathion is greatest for agricultural workers but may also be considerable for workers in plants which
 

produce the compound. The general public may be exposed to dioxathion
 

in house and garden pesticides for evergreens and shrubs (Gosselin et
 

al., 1976) and to airborne dioxathion in agricultural regions following spraying operations. Dioxathion is nonvolatile and relatively
 

stable (Farm Chemicals Handbook, 1976); consequently, exposure via ingestion may occur as a result of persistence and possible accumulation
 

of residues on treated crops and livestock.
 

Organophosphorous insecticides, which are chemically related to
 

the nerve gases, are among the most toxic pesticides in current use
 

i
 

(Gosselin et al., 1976; Hall, 1950). These compounds act as powerful
 

cholinesterase inhibitors throughout the body, and can be absorbed to
 

a dangerous degree through all routes, including the intact skin.
 

Inhalation is considered to be the most dangerous route of exposure,
 

followed by ingestion (Gosselin et al., 1976); oral intake of dioxathion in quantities greater than 0.075 mg/kg produces measurable
 

cholinesterase inhibition in humans (Spencer, 1973).
 

The initial symptoms of Organophosphorous insecticide poisoning
 

vary with the site of absorption: nausea, vomiting, diarrhea, and
 

sialorrhea after ingestion; rhinorrhea and a feeling of tightness of
 

the chest following inhalation; miosis, blurring or dimness of vision,
 

tearing, and ciliary muscle spasms after ocular exposure; and local
 

sweating and twitching following dermal contact (Gosselin et al.,
 
1976). Progressive loss of muscular control, due to the build-up of
 

acetylcholine at the neuromuscular junctions, occurs regardless of
 

the route of exposure and results in slurring of speech, difficulty
 

in breathing, fasciculations and twitching, and an overall loss of
 

coordination. In severe cases, convulsions, incontinence, random
 

jerky movements, and coma may ensue. When de^th occurs, it is
 

usually due to respiratory failure.
 
II. MATERIALS AND METHODS
 

A. Chemicals
 

Commercial technical-grade dioxathion (Figure 1) (Delnav ) was
 

purchased from Hercules, Incorporated as a single lot and analyzed
 

for purity by Hazleton Laboratories America, Inc., Vienna, Virginia.
 

Dioxathion, a liquid existing in the cis and trans geometric forms,
 

is sensitive to both heat and alkali.
 

The first analysis, one month prior to initiation of the chronic
 

bioassay, was by gas-liquid chromotography (GLC). It was felt that,
 

although dioxathion undergoes thermal decomposition in the chromatograph inlet to produce numerous compounds, a GLC profile would be
 

useful for comparisons from one year to the next. In this way,
 

changes in the chromatogram might indicate any alterations in the
 

composition of the chemical due to storage.
 

The second analysis, performed approximately one year later, was
 

by both GLC and a cleavage-hydrolysis gravimetric method suggested by
 

the manufacturer. The chromatogram from this second GLC analysis was
 

in general agreement with that of the first year. A mean dioxathion
 

content of approximately 69 percent was indicated using the gravimetric method and this was in accord with the manufacturer's stated
 

analysis of a mean dioxathion content ranging from 68 to 75 percent.
 

It was noted by the manufacturer that, although the gravimetric method
 

does not differentiate the cis and trans isomers, "the trans isomer
 

predominates.
 

4
 
s 

S - P - O - CH2CH3 

0 - CH2 CH3 

S 

S -P- O - CH9 CHo 

1 ^ J 

O - CH2 CH3 

FIGURE 1 

CHEMICAL STRUCTURE OF DIOXATHIOIM 
The third and last analysis, performed approximately two years
 

after the first one, was by the gravimetric method alone. The mean
 

dioxathion content was indicated to be approximately 56 percent,
 

considerably lower than the mean detected the previous year. It was,
 

therefore, concluded that chemical degradation had occurred.
 

Throughout this report the term dioxathion is used to represent
 

this commercial technical-grade material.
 

B.	 Dietary Preparation
 

The basal laboratory diet for both treated and control animals
 

(R)
 consisted of Wayne Lab-Blox^(Allied Mills, Inc., Chicago, Illinois)
 A
 

plus 2 percent Duke's corn oil (S. F. Sauer Company, Richmond,
 

Virginia) by weight. Fresh mixtures of dioxathion in corn oil were
 

prepared each week and stored in the dark. The dioxathion mixtures
 

were incorporated into the appropriate amount of laboratory diet in a
 

twin-shell blender fitted with an accelerator bar.
 

C. Animals
 

Two animal species, rats and mice, were used in the carcinogenicity bioassay. The Osborne-Mendel rat was selected on the basis of a
 

comparative study of the tumorigenic responsiveness to carbon tetrachloride of five different strains of rats (Reuber and Glover, 1970).
 

The B6C3F1 mouse was selected because it has been used by the NCI for
 

carcinogenesis bioassays and has proved satisfactory in this capacity.
 

Rats and mice of both sexes were obtained through contracts of
 

the Division of Cancer Treatment, National Cancer Institute. The
 
Osborne-Mendel rats were procured from the Battelle Memorial Institute, Columbus, Ohio, and the B6C3F1 mice were obtained from the
 

Charles River Breeding Laboratories, Inc., Wilmington, Massachusetts,
 

Upon receipt, animals were quarantined for at least 10 days, observed
 

for visible signs of disease or parasites, and assigned to the various
 

treated and control groups.
 

D, Animal Maintenance
 

All animals were housed by species in temperature- and humidity-


controlled rooms. The temperature range was 20° to 24°C and the
 

relative humidity was maintained between 45 and 55 percent. The air
 

conditioning system in the laboratory provided filtered air at a rate
 

of 10 to 15 complete changes of room air per hour. Fluorescent lighting was provided on a 12-hour-daily cycle.
 

The rats were individually housed in suspended galvanized-steel
 

wire-mesh cages with perforated floors, while mice were housed by sex
 

in groups of ten in solid-bottom polycarbonate cages equipped with
 

filter tops. Sanitized cages with fresh bedding (Sanichips , Pine-


wood Sawdust Company, Moonachie, New Jersey) were provided once each
 

week for mice. Rats received sanitized cages with no bedding with
 

the same frequency. Food hoppers were changed and heat-sterilized
 

once a week for the first 10 weeks and once a month thereafter, while
 

fresh heat-sterilized glass water bottles and sipper tubes were provided three times a week. Food and water were available ad libitum.
 
Treated and control rats were housed in the same room with other
 

rats receiving diets containing trifluralin (1582-09-8); endosulfan
 

(115-29-7); dicofol (115-32-2); nitrofen (1836-75-5); and mexacarbate
 

(315-18-4).
 

All mice used in the dioxathion study were housed in the same
 

room as other mice receiving diets containing trifluralin (1582-09­

8); chlorobenzilate (510-15-6); sulfallate (95-06-7); p,p'-DDT (50­

29-3); methoxychlor (72-43-5); p,p'-DDE (72-55-9); p,p'-TDE (72-54-8);
 

dicofol (115-32-2); pentachloronitrobenzene (82-68-8); clonitralid
 

(1420-04-8); nitrofen (1836-75-5); endosulfan (115-29-7); mexacarbate
 

(315-18-4); amitrole (61-82-5); safrole (94-59-7); and acetylaminofluorene (53-96-3).
 

E. Selection of Initial Concentrations
 

In order to establish the maximum tolerated concentrations of
 

dioxathion for administration to treated animals in the chronic
 

studies, subchronic toxicity studies were conducted with both rats
 

and mice. Animals of each species were distributed among six groups,
 

each consisting of five males and five females. Dioxathion was
 

premixed with a small amount of corn oil. This mixture was then
 

incorporated into the laboratory diet and fed ad libitum to five of
 

the six rat groups in concentrations of 21, 46, 100, 215, and 464
 

ppm, and to five of the six mouse groups in concentrations of 251,
 

398, 631, 1000, and 1590 ppm. The sixth group of each species served
 

*
 

CAS registry numbers are given in parentheses.
 
as a control group, receiving only the mixture of corn oil and laboratory chow. The dosed dietary preparations were administered for a
 

period of 6 weeks, followed by a 2-week observation period during
 

which all animals were given the basal diet.
 

A concentration inducing no mortality and resulting in a depression in mean group body weight of approximately 20 percent relative
 

to controls was selected as the initial high concentration for the
 

chronic study. When weight gain criteria were not applicable, mortality data alone were utilized.
 

All male rats treated with 215 ppm or less survived the entire
 

8-week period. Mean body weight depression was 10 percent in the
 

males receiving 100 ppm and 27 percent in the males receiving 215 ppm.
 

In the female rat groups, one of the five animals treated with 21 ppm
 

died, no females died at 46 ppm, and two of the five treated with 100
 

ppm died during the study. Significant mean body weight depression
 

was not observed in the females receiving 100 ppm or less. The
 

initial high concentrations selected for the chronic bioassay were
 

150 ppm for the male rats and 75 ppm for the female rats.
 

In the mice one male receiving 398 ppm, four males receiving
 

1000 ppm, three males receiving 1590 ppm, and one female treated with
 

1000 ppm died during the study. The initial high concentrations
 

selected for the chronic bioassay were 450 ppm for male mice and 700
 

ppm for the female mice.
 
F. Experimental Design
 

The experimental design parameters for the chronic study (species, sex, group size, actual concentrations administered, duration
 

of treated and untreated observation periods, and the time-weighted
 

average concentrations) are summarized in Tables 1 and 2.
 

Rats were all approximately 6 weeks old at the time they were
 

placed on test. The concentrations of dioxathion initially utilized
 

for male rats were 150 and 75 ppm. Throughout this report those male
 

rats initially receiving the former concentration are referred to as
 

the high dose group and those initially receiving the latter concentration are referred to as the low dose group. The initial concentrations utilized for the females were 75 and 37 ppm. Throughout this
 

report those female rats initially receiving the former concentration
 

are referred to as the high dose group while those initially receiving
 

the latter concentration are referred to as the low dose group. In
 

week 32 of the study high and low dioxathion levels were increased,
 

respectively, to 200 and 100 ppm for the males, and to 100 and 50 ppm
 

for the females. These concentrations were maintained until the end
 

of the period of compound administration. Final observations on all
 

rats were made 111 weeks after the experiment began.
 

Mice were all approximately 6 weeks old at the time they were
 

placed on test. The concentrations initially administered to the
 

male mice were 450 and 225 ppm. Throughout this report those male
 

mice initially receiving the former concentration are referred to
 

10
 
TABLE 1
 

DESIGN SUMMARY FOR OSBORNE-MENDEL RATS
 

DIOXATHION FEEDING EXPERIMENT
 

INITIAL OBSERVATION PERIOD TIME-WEIGHTED
 

GROUP DIOXATHION TREATED UNTREATED AVERAGE
 

SIZE CONCENTRATION' 1

 (WEEKS) (WEEKS) CONCENTRATION
 

MALE
 

CONTROL 50 0 JJ 111 0
 

LOW DOSE 50 75 31 90
 

1UO 47
 

0 33
 

HIGH DOSE 50 151 31 ISO
 

200 47
 

0 33
 

FEMALE
 

CONTROL 50 0 Q 111 B
 

LOW DOSE 50 3? 31 4*
 

5Q 47
 

0 33
 

HIGH DOSE 50 15, 31 W 

100 47 

0 33 

a . . .
 Concentrations given in parts per million.
 

b 2 (concentration X weeks received)
 Ti tnp-Tjpi ohf f»d aver;upe ronrpnfratir
 S(weeks receiving chemical)
 

11
 
TABLE 2
 

DESIGN SUMMARY FOR B6C3F1 MICE
 

DIOXATHION FEEDING EXPERIMENT
 

INITIAL OBSERVATION PERIOD TIME -WEIGHTED 

GROUP DIOXATHION TREATED UNTREATED AVERAGE 

SIZE CONCENTRATION 3

 (WEEKS) (WEEKS) CONCENTRATION 

MALE
 

CONTROL 20 « 0 tt «
 

LOW DOSE 50 225 17 284
 

300 ii
 

8 la
 

HIGH DOSE 50 450 11 567
 

600 &L
 

0 13
 

FEMALE
 

CONTROL 20 0 o m o
 

LOW DOSE 50 350 •U 467
 

500 il
 

0 13
 

HIGH DOSE 50 700 11 935
 

1000 61
 

0 13
 

a .. .
 Concentrations given in parts per million.
 

b 2 (concentration X weeks received)
 Ti me— UPI oh tpd avprase conrpnfrati
 

(weeks receiving chemical)
 

12
 
as the high dose group while those initially receiving the latter
 

concentration are referred to as the low dose group. Female mice
 

initially received concentrations of 700 and 350 ppm. Throughout
 

this report those female mice initially receiving the former concentration are referred to as the high dose group while those initially
 

receiving the latter concentration are referred to as the low dose
 

group. In week 18 of the study, the high and low dosages were increased to 600 and 300 ppm, respectively for the male mice, and to
 

1000 and 500 ppm, respectively, for the female mice. These concentrations were maintained for the remainder of the dosing period.
 

Final observations on all mice were made 90 to 91 weeks after the
 

experiment began.
 

G. Clinical and Hispathologic Examinations
 

Animals were weighed immediately prior to initiation of the
 

experiment. Body weights, food consumption, and data concerning
 

appearance, behavior, signs of toxic effects, and incidence, size,
 

and location of tissue masses were recorded at weekly intervals for
 

the first 10 weeks and at monthly intervals thereafter. From the
 

first day, all animals were inspected daily for mortality. The
 

presence of tissue masses was determined by observation and palpation
 

of each animal.
 

During the course of this bioassay several pathology protocols
 

were in effect, each for different periods of time. The minimum protocol required that, if possible, certain tissues were to be taken
 
and examined histopathologically from all control animals, from any
 

animal in which a tumor was observed during gross examination, and
 

from at least 10 grossly normal males and 10 grossly normal females
 

from each treated group. In addition, any tissues showing gross abnormalities were to be taken and examined histopathologically. Under
 

later protocols, some tissues were taken from additional dosed animals. The number of animals in each group from which a tissue was
 

examined is indicated in Appendices A through D.
 

A necropsy was performed on each animal regardless of whether it
 

died, was killed when moribund, or was sacrificed at the end of the
 

bioassay. The animals were euthanized by exsanguination under sodium
 

pentobarbital anesthesia, and were immediately necropsied. The histopathologic examination consisted of gross and microscopic examination
 

of major tissues, organs, and gross lesions taken from sacrificed
 

animals and, whenever possible, from animals found dead.
 

Tissues were preserved in 10 percent buffered formalin, embedded
 

in paraffin, sectioned, and stained with hematoxylin and eosin prior
 

to microscopic examination. An occasional section was subjected to
 

special staining techniques for more definitive diagnosis.
 

Slides were prepared from the following tissues from selected
 

animals: skin, subcutaneous tissue, muscle, lungs and bronchi,
 

trachea, bone marrow, spleen, lymph nodes, thymus, heart, salivary
 

gland, liver, gallbladder (mice), pancreas, esophagus, stomach, small
 

intestine, large intestine, kidney, urinary bladder, pituitary,
 

14
 
adrenal, thyroid, parathyroid, testis, prostate, seminal vesicle,
 

brain, uterus, mammary gland, and ovary.
 

A few tissues were not examined for some animals, particularly
 

for those that died early. Also, some animals were missing, cannibalized, or judged to be in such an advanced state of autolysis as to
 

preclude histopathologic interpretation. Thus, the number of animals
 

for which particular organs, tissues, or lesions were examined microscopically varies and does not necessarily represent the number of
 

animals that were placed on experiment in each group.
 

H. Data Recording and Statistical Analyses
 

Pertinent data on this experiment have been recorded in an automatic data processing system, the Carcinogenesis Bioassay Data System
 

(Linhart et al., 1974). The data elements include descriptive information on the chemicals, animals, experimental design, clinical observations, survival, body weight, and individual pathologic results,
 

as recommended by the International Union Against Cancer (Berenblum,
 

1969). Data tables were generated for verification of data transcription and for statistical review.
 

These data were analyzed using the statistical techniques described in this section. Those analyses of the experimental results
 

that bear on the possibility of carcinogenicity are discussed in the
 

statistical narrative sections.
 

Probabilities of survival were estimated by the product-limit
 

procedure of Kaplan and Meier (1958) and are presented in this report
 

IS
 
in the form of graphs. Animals were statistically censored as of the
 

time that they died of other than natural causes or were found to be
 

missing; animals dying from natural causes were not statistically
 

censored. Statistical analyses for a possible dose-related effect
 

on survival used the method of Cox (1972) when testing two groups for
 

equality and used Tarone's (1975) extensions of Cox's methods when
 

testing a dose-related trend. One-tailed P-values have been reported
 

for all tests except the departure from linearity test, which is only
 

reported when its two-tailed P-value is less than 0.05.
 

The incidence of neoplastic or nonneoplastic lesions has been
 

given as the ratio of the number of animals bearing such lesions at a
 

specific anatomic site (numerator) to the number of animals in which
 

that site was examined (denominator). In most instances, the denominators included only those animals for which that site was examined
 

histologically. However, when macroscopic examination was required
 

to detect lesions prior to histologic sampling (e.g., skin or mammary
 

tumors), or when lesions could have appeared at multiple sites (e.g.,
 

lymphomas), the denominators consist of the numbers of animals necropsied.
 

The purpose of the statistical analyses of tumor incidence is to
 

determine whether animals receiving the test chemical developed a significantly higher proportion of tumors than did the control animals.
 

As a part of these analyses, the one-tailed Fisher exact test (Cox,
 

1970, pp. 48-52) was used to compare the tumor incidence of a control
 
group to that of a group of treated animals at each dose level. When
 

results for a number of treated groups, k, are compared simultaneously
 

with those for a control group, a correction to ensure an overall
 

significance level of 0.05 may be made. The Bonferroni inequality
 

(Miller, 1966, pp. 6-10) requires that the P-value for any comparison
 

be less than or equal to 0.05/k. In cases where this correction was
 

used, it is discussed in the narrative section. It is not, however,
 

presented in the tables, where the Fisher exact P-values are shown.
 

The Cochran-Armitage test for linear trend in proportions, with
 

continuity correction (Armitage, 1971, pp. 362-365), was also used
 

when appropriate. Under the assumption of a linear trend, this test
 

determined if the slope of the dose-response curve is different from
 

zero at the one-tailed 0.05 level of significance. Unless otherwise
 

noted, the direction of the significant trend was a positive dose relationship. This method also provides a two-tailed test of departure
 

from linear trend.
 

A time-adjusted analysis was applied when numerous early deaths
 

resulted from causes that were not associated with the formation of
 

tumors. In this analysis, deaths that occurred before the first
 

tumor was observed were excluded by basing the statistical tests on
 

animals that survived at least 52 weeks, unless a tumor was found at
 

the anatomic site of interest before week 52. When such an early
 

tumor was found, comparisons were based exclusively on animals that
 

survived at least as long as the animal in which the first tumor was
 

17
 
found. Once this reduced set of data was obtained, the standard procedures for analyses of the incidence of tumors (Fisher exact tests,
 

Cochran-Armitage tests, etc.) were followed.
 

When appropriate, life-table methods were used to analyze the
 

incidence of tumors. Curves of the proportions surviving without an
 

observed tumor were computed as in Saffiotti et al. (1972). The week
 

during which animals died naturally or were sacrificed was entered as
 

the time point of tumor observation. Cox's methods of comparing
 

these curves were used for two groups; Tarone's extension to testing
 

for linear trend was used for three groups. The statistical tests for
 

the incidence of tumors which used life-table methods were one-tailed
 

and, unless otherwise noted, in the direction of a positive dose
 

relationship. Significant departures from linearity (P < 0.05, two-


tailed test) were also noted.
 

The approximate 95 percent confidence interval for the relative
 

risk of each dosed group compared to its control was calculated from
 

the exact interval on the odds ratio (Gart, 1971). The relative risk
 

is defined as p /p where p is the true binomial probability of the
 

incidence of a specific type of tumor in a treated group of animals
 

and p is the true probability of the spontaneous incidence of the
 

c
 

same type of tumor in a control group. The hypothesis of equality
 

between the true proportion of a specific tumor in a treated group
 

and the proportion in a control group corresponds to a relative risk
 

18
 
of unity. Values in excess of unity represent the condition of a
 

larger proportion in the treated group than in the control.
 

The lower and upper limits of the confidence interval of the
 

relative risk have been included in the tables of statistical analyses. The interpretation of the limits is that in approximately 95
 

percent of a large number of identical experiments, the true ratio
 

of the risk in a treated group of animals to that in a control group
 

would be within the interval calculated from the experiment. When
 

the lower limit of the confidence interval is greater than one, it
 

can be inferred that a statistically significant result (a P < 0.025
 

one-tailed test when the control incidence is not zero, P < 0.050
 

when the control incidence is zero) has occurred. When the lower
 

limit is less than unity but the upper limit is gjreater than unity,
 

the lower limit indicates the absence of a significant result while
 

the upper limit indicates that there is a theoretical possibility
 

of the induction of tumors by the test chemical which could not be
 

detected under the conditions of this test.
 
III. CHRONIC TESTING RESULTS: RATS
 

A. Body Weights and Clinical Observations
 

No distinct dose-related mean body weight depression was apparent
 

in either male or female rats (Figure 2).
 

During the first year of the study the appearance and behavior
 

of the treated rats were generally comparable to that of the controls
 

except that intermittent or occasional hunched appearance, squinted
 

or reddened eyes and urine stains on the abdomen were observed in
 

several treated rats. From week 54 to cessation of dosing in week 78,
 

clinical signs were observed with slightly greater frequency in the
 

treated groups than in the controls, but were noted at comparable
 

rates in treated and control animals during the remainder of the
 

study. Signs commonly associated with aging and observed at comparable rates in control and treated rats included body sores, alopecia, rough or stained fur, palpable nodules or tissue masses and/or
 

bloating. Respiratory signs characterized by labored respiration,
 

wheezing and/or nasal discharge were generally observed at a low
 

incidence in all groups during the study. Isolated, sporadic, and
 

spontaneous observations in one to three treated rats included
 

tremors, head tilt, hyperactivity, apparent hind-limb paralysis and
 

small gonads.
 

B. Survival
 

The estimated probabilities of survival for male and female rats
 

in the control and dioxathion-dosed groups are shown in Figure 3.
 

20
 
TIME ON TEST (WEEKS) 

CD 

uj 

g 

§300­

CO 

CONTROL 

LOW DOSE 

HIGH DOSE 

FEMALE RATS 

I I I 

15 30 45 60 105 

TIME ON TEST (WEEKS) 

FIGURE 2 

GROWTH CURVES FOR DIOXATHION CHRONIC STUDY RATS 

21 

120 
PROBABILITY OF SURVIVAL PROBABILITY OF SURVIVAL 

3J 

< 

> 

8 g*~ 

5 

z 

o

I 

3D 

o 
For both male and female rats the Tarone test did not indicate a
 

significant association between increased dosage and elevated mortality.
 

For males adequate numbers of rats were at risk from late-


developing tumors as 50 percent (25/50) of the high dose, 46 percent
 

(23/50) of the low dose, and 48 percent (24/50) of the control group
 

survived on test until the end of the study. For females the survival was also adequate as 68 percent (34/50) of the high dose, 62
 

percent (31/50) of the low dose, and 72 percent (36/50) of the control rats survived on test until the end of the study.
 

C. Pathology
 

Histopathologic findings on neoplasms in rats are tabulated in
 

Appendix A (Tables Al and A2); findings on nonneoplastic lesions are
 

tabulated in Appendix C (Tables Cl and C2).
 

A variety of neoplasms was represented among both the treated
 

and control rats. Each of the types of tumors represented has been
 

encountered before as a naturally occurring lesion in the Osborne-


Mendel rat and is without apparent relationship to the administration
 

of the chemical.
 

Inflammatory, degenerative, and proliferative lesions seen in
 

treated and control animals were similar to those naturally occurring
 

in untreated aged rats.
 

Based upon this histopathologic examination, dioxathion was not
 

toxic or carcinogenic in Osborne-Mendel rats at the doses administered,
 

23
 
D. Statistical Analyses of Results
 

The results of the statistical analyses of tumor incidence in
 

rats are summarized in Tables 3 and 4. The analysis is included for
 

every type of tumor in either sex where at least two malignant tumors
 

were observed at one site in at least one of the control or dioxathiondosed groups and where such tumors were observed in at least 5 percent
 

of the group.
 

In male rats the incidence of pituitary chromophobe adenoma was
 

relatively high in the low dose group (30 percent). The Fisher exact
 

test comparing low dose to control, however, had a probability level
 

of P = 0.041, a marginal result which was not significant under the
 

Bonferroni criterion.
 

No statistical tests indicated a positive association between
 

chemical administration and tumor incidence at any of the other sites
 

tested for male or female rats. Based upon these results there was
 

no convincing evidence of the carcinogenicity of dioxathion in
 

Osborne-Mendel rats.
 

The possibility of a negative association between dosage and the
 

incidence of hemangiosarcomas of the subcutaneous tissue was observed
 

for female rats. The Fisher exact tests, however, were not significant.
 

To provide additional insight into the possible carcinogenicity
 

of this compound, 95 percent confidence intervals on the relative
 

risk have been estimated and entered in the tables based upon the
 

24
 
TABLE 3 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT 

SPECIFIC SITES IN MALE RATS TREATED WITH DIOXATHION* 

TOPOGRAPHY: MORPHOLOGY CONTROL 

LOW 

DOSE 

HIGH 

DOSE 

Subcutaneous Tissue: Hemangiosarcoma 

P Values0 

Relative Risk (Control) 

Lower Limit 

Upper Limit 

4/49(0.08) 

N.S. ___ 

0/50(0.00) 

N.S. 

0.000 

0.000 

1.057 

1/50(0.02) 

N.S. 

0.245 

0.005 

2.362 

Weeks to First Observed Tumor 72 77 

01 

Spleen: Hemangiosarcoma 

P Values0 

Relative Risk (Control) 

Lower Limit 

Upper Limit 

4/47(0.09) 

N.S. _.__ 

0/23(0.00) 

N.S. 

0.000 

0.000 

2.136 

2/29(0.07) 

N.S. 

0.810 

0.077 

5.225 

Weeks to First Observed Tumor 90 88 

Pituitary: Chromophobe Adenoma 4/41(0.10) 7/23(0.30) 5/27(0.19) 

P Values N.S. P = 0.041 N.S. 

Relative Risk (Control) 

Lower Limit 

Upper Limit 

Weeks to First Observed Tumor 

_~ 

108 

3.120 

0.885 

12.690 

77 

1.898 

0.448 

8.638 

94 
___ 

___ 

TABLE

TOPOGRAPHY: MORPHOLOGY
 

Pancreatic Islets: Islet-Cell Adenoma
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Thyroid: C-Cell Carcinoma
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Thyroid: C-Cell Adenoma or C-Cell
 

Carcinoma*3
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

3 (CONTINUED) 

CONTROL
 

1/46(0.02)
 

N.S.
 

*K1-T*¥«*
 

—11­1 

0/48(0.00)
 

w*s.
 

*-*^-^-

—
 '
 

0/48(0.00)
 

N.S.
 

—_
 

«M*M
 

»—_
 

LOW
 

DOSE
 

2/23(0.09)
 

N.S.
 

4.000
 

0.217
 

225.008
 

111
 

2/49(0.04)
 

N.S.
 

Infinite
 

0.290
 

Infinite
 

111
 

3/49(0.06)
 

N.S.
 

Infinite
 

0.590
 

Infinite
 

111
 

HIGH
 

DOSE
 

2/30(0.07)
 

N.S.
 

3.067
 

0.166
 

174.643
 

106
 

3/49(0.06)
 

N.S.
 

Infinite
 

0.590
 

Infinite
 

111
 

4/49(0.08)
 

N.S.
 

Infinite
 

0.909
 

Infinite
 

106
 
TABLE 3 (CONCLUDED)
 

LOW HIGH 

TOPOGRAPHY rMORPHOLOGY CONTROL DOSE DOSE 

Thyroid: Follicular-Cell Carcinoma 4/48(0.08) 4/49(0.08) 3/49(0.06) 

P Values0 N.S. N.S. N.S. 

e Departure from Linear Trend P = 0.038 

Relative Risk (Control) —_ 0.980 0.735 

Lower Limit 0.193 0.113 

Upper Limit __­ 4.972 4.114 

Weeks to First Observed Tumor 106 ill 94 

Thyroid: Follicular-Cell Adenoma or 

Follicular-Cell Carcinomab 5/48(0.10) 8/49(0.16) 7/49(0.14) 

P Values0 N.S. N.S. N.S. ___ 

Relative Risk (Control) 1.567 1.371 

Lower Limit 0.489 0.403 

Upper Limit 5.678 5.119 

Weeks to First Observed Tumor 106 gg 94 

a
 

Treated groups received time-weighted average doses of 90 or 180 ppm in feed.
 

Number of tumor-bearing animals/number of animals examined at site (proportion).
 

The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the control group when P < 0.05; otherwise, not significant (N.S.) is indicated. The
 

probability level for the Fisher exact test for the comparison of a treated group with the
 

control group is given beneath the incidence of tumors in the treated group when P < 0.05;
 

otherwise, not significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact
 

tests a negative designation (N) indicates a lower incidence in the treated group(s) than
 

in the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 

probability level of the test for departure from linear trend is given beneath the control
 

group when P < 0.05.
 
__ 

00 

TABLE 4
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT
 

SPECIFIC SITES IN FEMALE RATS TREATED WITH DIOXATHION*
 

TOPOGRAPHY: MORPHOLOGY
 

Subcutaneous Tissue: Hemangiosarcoma
 

P Values
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Kidney: Hemangiosarcoma
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Pituitary: Chromophobe Adenoma
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

CONTROL
 

3/50(0.06)
 

P = 0.037(N)
 

89
 

0/50(0.00)
 

N.S.
 

15/50(0.30)
 

N.S.
 

100
 

LOW
 

DOSE
 

0/50(0.00)
 

N.S.
 

0.000
 

0.000
 

1.663
 

2/40(0.05)
 

N.S.
 

Infinite
 

0.370
 

Infinite
 

f5
 

9/40(0.23)
 

N.S.
 

0.750
 

0.324
 

1.621
 

78
 

HIGH
 

DOSE
 

0/50(0.00)
 

N.S.
 

0.000
 

0.000
 

1.663
 

0/37(0.00)
 

N.S.
 

15/39(0.38)
 

N.S.
 

1.282
 

0.668
 

2.423
 

99 
___ 

___ 

TOPOGRAPHY: MORPHOLOGY
 

Thyroid: C-Cell Carcinoma
 

P Values
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Thyroid: C-Cell Adenoma or C-Cell
 

Carcinoma^
 

N3 P Values0
 

VO
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Mammary Gland: Fibroadenoma
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

TABLE 4 (CONTINUED)
 

CONTROL
 

0/50(0.00)
 

N.S.
 

—„
 

—*«•-,
 

5/50(0.10)
 

N.S.
 

~~*<-*
 

111
 

15/50(0.30)
 

N.S.
 

-*-­ _TM
 

— _^
 

87
 

LOW
 

DOSE
 

2/33(0.06)
 

N.S.
 

Infinite
 

0.449
 

Infinite
 

95
 

5/33(0.15)
 

N.S.
 

1.515
 

0.374
 

6.026
 

95
 

13/50(0.26)
 

N.S.
 

0.867
 

0.426
 

1.742
 

89
 

HIGH
 

DOSE
 

2/34(0.06)
 

N.S.
 

Infinite
 

0.433
 

Infinite
 

111
 

2/34(0.06)
 

N.S.
 

0.588
 

0.058
 

3.338
 

111
 

12/50(0.24)
 

N.S.
 

0.800
 

0.383
 

1.635
 

105 
___ 

TABLE 4 (CONCLUDED)
 

LOW HIGH
 

TOPOGRAPHY: MORPHOLOGY CONTROL DOSE DOSE
 

Uterus: Endometrial Stromal Polyp 4/49(0.08) 2/34(0.06) 1/31(0.03)
 

P Values0 N.S. N.S. N.S.
 

Relative Risk (Control) 0.721 0.395
 

Lower Limit 0.068 0.008
 

Upper Limit 4.696 3.729
 

Weeks to First Observed Tumor Ill 106 111
 

Treated groups received time-weighted average doses of 45 or 90 ppm in feed.
 

Number of tumor-bearing animals/number of animals examined at site (proportion).
 oo
 

o
 The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the control group when P < 0.05; otherwise, not significant (N.S.) is indicated. The
 

probability level for the Fisher exact test for the comparison of a treated group with the
 

control group is given beneath the incidence of tumors in the treated group when P < 0.05;
 

otherwise, not significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact
 

tests a negative designation (N) indicates a lower incidence in the treated group(s) than
 

in the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 
observed tumor incidence rates. In all of the intervals shown in
 

Tables 3 and 4, the value one is included; this indicates the absence
 

of statistically significant results. It should also be noted that
 

all of the confidence intervals have an upper limit greater than one,
 

indicating the theoretical possibility of tumor induction in rats by
 

dioxathion that could not be established under the conditions of this
 

test.
 

31
 
IV. CHRONIC TESTING RESULTS: MICE
 

A. Body Weights and Clinical Observations
 

Distinct, dose-related mean body weight depression was observed
 

among the female mice. This same trend was not, however, apparent in
 

the male mice (Figure 4).
 

There was no evidence that dioxathion, at the concentrations
 

used in this bioassay, produced any effect on physical appearance or
 

behavior of the treated mice. Signs often observed in group-housed
 

laboratory mice were noted at a comparable rate in control and
 

treated animals, with the incidence increasing gradually as the animals aged. These signs included sores and/or desquamation on parts
 

of the body (more prevalent in males due to fighting), localized
 

alopecia, abdominal urine stains, penile, vulvar or anal irritation,
 

bloated appearance, and palpable nodules and/or tissue masses.
 

B. Survival
 

The estimated probabilities of survival for male and female mice
 

in the control and dioxathion-dosed groups are shown in Figure 5.
 

For both male and female mice the Tarone test did not indicate a
 

significant association between increased dosage and elevated mortality.
 

For males adequate numbers of mice were at risk from late-


developing tumors as 74 percent (37/50) of the high dose, 70 percent
 

(35/50) of the low dose, and 80 percent (16/20) of the control group
 

survived on test until the end of the study. For females the survival
 

32
 
50­

cc 

>­ 20­ Q 

O 

CONTROL 

LOW DOSE 

HIGH DOSE 

MALE MICE 

45 60 75 105 120 

TIME ON TEST (WEEKS) 

TIME ON TEST (WEEKS) 

FIGURE 4 

GROWTH CURVES FOR DIOXATHION CHRONIC STUDY MICE 

33 
PROBABILITY OF SURVIVAL PROBABILITY OF SURVIVAL 

I 

o 

-n O 

2-n 

I

m 

I

i

"

o 

g­
was also adequate as 90 percent (45/50) of the high dose, 92 percent
 

(46/50) of the low dose, and 90 percent (18/20) of the control mice
 

survived on test until the end of the study.
 

C. Pathology
 

Histopathologic findings on neoplasms in mice are tabulated in
 

Appendix B (Tables Bl and B2); findings on nonneoplastic lesions are
 

tabulated in Appendix D (Tables Dl and D2).
 

A variety of neoplasms was present in both the treated and
 

control mice. Each of the types of tumors represented has been
 

encountered previously as a spontaneous lesion in B6C3F1 mice and is
 

apparently unrelated to the administration of dioxathion.
 

The inflammatory, degenerative, and proliferative lesions that
 

occurred in the control and treated animals were also without appreciable difference from the number and kind of naturally, occurring
 

lesions found in untreated aged mice.
 

Based upon this histopathologic examination, dioxathion was not
 

toxic or carcinogenic in B6C3F1 mice at the doses administered.
 

D. Statistical Analyses of Results
 

The results of the statistical analyses of tumor incidence in
 

mice are summarized in Tables 5 and 6. The analysis is included for
 

every type of tumor in either sex where at least two malignant tumors
 

were observed in at least one of the control or dioxathion-dosed
 

groups and where such tumors were observed in at least 5 percent of
 

the group.
 
___ 

___ 

TABLE 5
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT
 

SPECIFIC SITES IN MALE MICE TREATED WITH DIOXATHION*
 

HIGH
 

DOSE
 

3/49(0.06)
 

N.S.
 

1.224
 

0.107
 

62.958
 

77
 

4/19(0.21)
 

N.S.
 

3.368
 

0.387
 

155.210
 

»
 

5/49(0.10)
 

N.S.
 

0.434
 

0.113
 

2.036
 

90
 

TOPOGRAPHY : MORPHOLOGY
 

Subcutaneous Tissue: Fibrosarcoma
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Lung: Alveolar /Bronchiolar Adenoma or
 

u> Alveolar/Bronchiolar Carcinoma'3
 

P Values0
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

b
 

Liver: Hepatocellular Carcinoma
 

c
 

P Values
 

Relative Risk (Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

CONTROL
 

1/20(0.05)
 

N.S.
 

—
 

90
 

1/16(0.06)
 

N.S.
 

.—_
 

»
 

4/17(0.24)
 

N.S.
 

90
 

LOW
 

DOSE
 

5/49(0.10)
 

N.S.
 

2.041
 

0.254
 

94.440
 

73
 

1/17(0.06)
 

N.S.
 

0.941
 

0.013
 

69.450
 

90
 

4/49(0.08)
 

N.S.
 

0.347
 

0.076
 

1.705
 

90
 
TABLE 5 (CONCLUDED) 

LOW HIGH
 

TOPOGRAPHY: MORPHOLOGY CONTROL DOSE DOSE
 

Liver: Hepatocellular Adenoma or
 

Hepatocellular Carcinoma*3 4/17(0.24) 4/49(0.08) 6/49(0.12)
 

P Values0 N.S. N.S. N.S.
 

Relative Risk (Control) 0.347 0.520
 

Lower Limit 0.076 0.150
 

Upper Limit 1.705 2.331
 

Weeks to First Observed Tumor 90 90 90
 

Treated groups received time-weighted average doses of 284 or 567 ppm in feed.
 

OJ Number of tumor-bearing animals/number of animals examined at site (proportion).
 -j
 

The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the control group when P < 0.05; otherwise, not significant (N.S.) is indicated. The
 

probability level for the Fisher exact test for the comparison of a treated group with the
 

control group is given beneath the incidence of tumors in the treated group when P < 0.05;
 

otherwise, not significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact
 

tests a negative designation (N) indicates a lower incidence in the treated group(s) than in
 

the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 
___ 

TABLE 6
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT
 

SPECIFIC SITES IN FEMALE MICE TREATED WITH DIOXATHION£
 

LOW HIGH
 

TOPOGRAPHY: MORPHOLOGY CONTROL DOSE DOSE
 

Hematopoietic Systems Malignant Lymphoma 2/19(0.11) 4/50(0.08) 1/49(0.02)
 

P Values0 M.S. N.S. N.S.
 

Relative Risk (Control) _—_ 0.760 0.194
 

Lower Limit 0.122 0.003
 

Upper Limit 7.931 3.561
 

Weeks to First Observed Tumor 90 73 91
 

Treated groups received time-weighted average doses of 467 or 935 ppm in feed.
 

oo Number of tumor-bearing animals/number of animals examined at site (proportion).
 

"The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the control group when P < 0.05; otherwise, not significant (N.S.) is indicated. The
 

probability level for the Fisher exact test for the comparison of a treated group with the
 

control group is given beneath the incidence of tumors in the treated group when P < 0.05;
 

otherwise, not significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact
 

tests a negative designation (N) indicates a lower incidence in the treated group(s) than
 

in the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 
None of the statistical tests for any site in mice of either sex
 

indicated a significant positive association between the administration of dioxathion and tumor incidence. Thus, at the dose levels
 

used in this experiment there was no convincing statistical evidence
 

that dioxathion was a carcinogen in B6C3F1 mice.
 

To provide additional insight into the possible carcinogenicity
 

of this compound, 95 percent confidence intervals on the relative
 

risk have been estimated and entered in the tables based upon the
 

observed tumor incidence rates. In all of the intervals shown in
 

Tables 5 and 6, the value one is included; this indicates the absence
 

of statistically significant results. It should also be noted that
 

all of the confidence intervals have an upper limit greater than one,
 

indicating the theoretical possibility of tumor induction in mice by
 

dioxathion that could not be established under the conditions of this
 

test.
 
V. DISCUSSION
 

Under the conditions of this bioassay, no significant positive
 

association was established between dietary administration of dioxathion and mortality in Osborne-Mendel rats or B6C3F1 mice of either
 

sex. Adequate numbers of animals in all groups survived sufficiently
 

long to be at risk from late-developing tumors. The possibility that
 

the animals in this bioassay did not receive dosages approximating
 

the maximum tolerated dosages must be considered. Dietary administration of dioxathion had no significant effect on survival in rats
 

or mice of either sex and it affected body weight gain in only the
 

female mice. No particularly unusual clinical observations were
 

reported during the bioassay in either sex of either species.
 

A variety of neoplasms was observed in treated animals of both
 

species; however, none of the neoplasms observed were either histopathologically unusual or in statistically significant incidences.
 

Under the conditions of this bioassay, dietary administration
 

of dioxathion was not carcinogenic in Osborne-Mendel rats or B6C3F1
 

mice.
 

40
 
VI. BIBLIOGRAPHY
 

Armitage, P., Statistical Methods in Medical Research, Chapter 14.
 

J. Wiley & Sons, New York, 1971.
 

Berenblum, I., editor, Carcinogenicity Testing. International Union
 

Against Cancer, Technical Report Series, Vol. 2. International
 

Union Against Cancer, Geneva, 1969.
 

Chemical Abstracts Service, The Chemical Abstracts Service (CAS)
 

Ninth Collective Index, Volumes 76-85, 1972-1976. American
 

Chemical Society, Washington, D.C., 1977.
 

Cox, D.R., Analysis of Binary Data, Chapters 4 and 5. Methuen and
 

Co., Ltd., London, 1970.
 

Cox, D.R., "Regression Models and Life-Tables." Journal of the Royal
 

Statistical Society, Series "B" 34:187-220, 1972.
 

Farm Chemicals Handbook. Meister Publishing Company, Willoughby,
 

Ohio, 1976.
 

Gart, J.J., "The Comparison of Proportions: A Review of Significance
 

Tests, Confidence Limits, and Adjustments for Stratification."
 

International Statistical Institute Review 39:148-169, 1971.
 

Gosselin, R.E., H.C. Hodge, R.P. Smith, and M.N. Gleason, Clinical
 

Toxicology of Commercial Products, 4th edition. The Williams
 

and Wilkins Company, Baltimore, Maryland, 1976.
 

Hall, S.A., "Organic Phosphorous Insecticides." Agricultural Control
 

Chemicals. American Chemical Society, New York, 1950.
 

Kaplan, E.L., and P. Meier, "Nonparametric Estimation from Incomplete
 

Observations." Journal of the American Statistical Association
 

J53^457-481, 1958.
 

Linhart, M.S., J.A. Cooper, R.L. Martin, N.P. Page, and J.A. Peters,
 

"Carcinogenesis Bioassay Data System." Computers and Biomedical
 

Research 7:230-248, 1974.
 

Miller, R.G., Simultaneous Statistical Inference. McGraw-Hill Book
 

Co., New York, 1966.
 

Reuber, M.D., and E.L. Glover, "Cirrhosis and Carcinoma of the Liver
 

in Male Rats Given Subcutaneous Carbon Tetrachloride." Journal
 

of the National Cancer Institute 44:419-423, 1970.
 

4l
 
Saffiotti, U., R. Montesano, A.R. Sellakumar, F. Cefis, and D.G.
 

Kaufman, "Respiratory Tract Carcinogenesis in Hamsters Induced
 

by Different Numbers of Administration of Benzo (a) Pyrene and
 

Ferric Oxide." Cancer Research 32:1073-1079, 1972.
 

Spencer, E.Y., Guide to the Chemicals Used in Crop Protection. Publication 1093, Information Canada, Ottawa, 1973.
 

Tarone, R.E., "Tests for Trend in Life-Table Analysis." Biometrika
 

£2_:679-682, 1975.
 

U.S.	 International Trade Commission, Synthetic Organic Chemicals,
 

United States Production and Sales, 1975. USITC Publication
 

804, U.S. Government Printing Office, Washington, D.C., 1977.
 

42
 
Review of the Bioassay of Dioxathion* for Carcinogenicity
 

by the Data Evaluation/Risk Assessment Subgroup
 

of the Clearinghouse on Environmental Carcinogens
 

Aoril 26, 1978
 

The Clearinghouse on Environmental Carcinogens was
 

established in May, 1976, in compliance with DHEW Committee
 

Regulations and the Provisions of the Federal Advisory
 

Committee Act. The purpose of the Clearinghouse is to
 

advise the Director of the National Cancer Institute (NCI)
 

on its bioassay program to identify and to evaluate chemical
 

carcinogens in the environment to which humans may be
 

exposed. The members of the Clearinghouse have been drawn
 

from academia, industry, organized labor, public interest
 

groups, State health officials, and quasi-public health and
 

research organizations. Members have been selected on the
 

basis of their experience in carcinogenesis or related
 

fields and, collectively, provide expertise in chemistry,
 

biochemistry, biostatistics, toxicology, pathology, and
 

epidemiology. Representatives of various Governmental
 

agencies participate as ad hoc members. The Data Evaluation/
 

Risk Assessment Subgroup of the Clearinghouse is charged
 

with the responsibility of providing a peer review of
 

reports prepared on NCI-sponsored bioassays of chemicals
 

studied for carcinogenicity. It is in this context that the
 

below critique is given on the bioassay of Dioxathion for
 

carcinogenicity.
 

The primary reviewer said that the compound was not
 

carcinogenic in rats or mice, under the conditions of test,
 

but did cause testicular atrophy in male rats. He said
 

the finding was particularly important since other pesticides
 

have been shown to produce testicular damage in exposed
 

chemical or farm workers. The primary reviewer commented
 

on a dose-related increase in the incidence of hyperplastic
 

nodules and nodular hyperplasia of the liver in male mice,
 

as well as on other lesions observed at elevated levels in
 

the treated animals. Given the widespread exposure to
 

Dioxathion, he recommended that the non-neoplastic findings
 

were sufficiently important to be noted in the report's
 

discussion and summary sections. Based on the bioassay,
 the primary reviewer concluded that Dioxathion does not
 

pose a carcinogenic risk to humans, although it may present
 

a risk for testicular damage.
 

43
 
The secondary reviewer agreed with the conclusion in
 

the report that Dioxathion was not carcinogenic under the
 

conditions of test. He noted that the dose administered
 

was increased during the course of the chronic study to
 

achieve a maximum tolerated dose.
 

A motion was approved unanimously that the report on
 

the bioassay of Dioxathion be accepted as written.
 

Members present were
 

Michael Shimkin (Acting Chairman), University of California
 

at San Diego
 

Joseph Highland, Environmental Defense Fund
 

George Roush, Jr., Monsanto Company
 

Louise Strong, University of Texas Health Sciences Center
 

John Weisburger, American Health Foundation
 

(Sidney Wolfe, Health Research Group, submitted a written review)
 

*	 Subsequent to this review, changes may have been made
 

in the bioassay report either as a result of the review
 

or other reasons. Thus, certain comments and criticisms
 

reflected in the review may no longer be appropriate.
 

<t u.S . GOVERNMEN T PRINTIN G OFFICE : 1978-260-899/316 1
 
APPENDIX A
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS
 

IN RATS TREATED WITH DIOXATHION
 

TABLE A1

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN MALE RATS TREATED WITH DIOXATHION 

CONTROL(TEH)

01-H001

 LOW DOSE

 01-B008

 HIGH

 01­

 DOSE 

M009 

ANIMAL S INITIALLY IN STUDY 50 50 50 ANIMAL S NECROPSIED U9 SO 50 

ANIMAL S EXAMINE D HISTOPATHOLOGICALLY ** U9 50 U9 

INTEGUMENTAR Y SYSTEM 

*SKIN (U9) f5CJ (50) 

HEBANGIOFERICYTOBA. MALIGNAN T 1 (2X) 

*SUBCUT TISSUE (<19) (50) (50) FIBROMA 1 (2X) 1 (2X) 

PIBROSARCOMA 1 (2X) 2 <4X) 

LIPOMA 2 (IX) 

HEMANGIOSABCOM A « (8X) 1 (2X) 

RESPIRATORY SYSTEM 

IIITNG («9) (3f) (10) 

BIXED TUMOR, MALIGNANT 1 (2X) 

HEMANGIOSA8COHA, BETASTATIC 2 (IX) 

HEMATOPOIETIC SYSTEM 

*BDLTIPLE ORGAN S (M9) ^50} (50) 

MALIG.LYMPHOMA , LYHPHOCYTIC TIPE 1 (2X) 1 (2X) 

LYSPHOCYTIC LEUKEMI A 1 (2X) 

*SDBCUT TISSUE/BACK (K9) (50) (50) 

MALIG.LYMPHOBA , HISTIOCYTIC TYPE 1 (2X) 

ISPLEBN (47) (23) (29) 

HEMANGIOSARCOM A U (9X) 2 (7X) 

CIRCULATOR Y SYSTEM 

• HEAR T (<I7) (2»; (28) 

HEKASGJO SARCOMA l_12Si 

# NUMBER OF ANIMAL S WITH TISSUE EXAMINE D MICROSCOPICALLY * DUMBER Of ANIMALS NECROPSIED 

"EXCLUDES PARTIALLY AUTOLYZED ANIMALS 
TABLE A1 (CONTINUED! 

CONTROL(VEH) LOW DOSE 

01-M001 01-M008 

HEMANGIOSABCOHA , METASTATIC 

iENDOCARDIOM (It 7) (21) 

SARCOMA, NOS 

DIGESTIVE SYSTEM
 

iLIVER (19) (37) 

HEMANGIOSARCOMA, BETASTATIC 

IPANCREAS (16) (23)
 ADENOCARCINOMA, NOS, METASTATIC 1 (IX)
 ACINAR-CELL ADENOMA
 

•STOMACH	 (16) (29)
 ADENOCARCINOMA, NOS 1 (3X)
 

ISMALL INTESTINE (16) (21)
 ADENOCARCINOBA, NCS, HETASTATIC 1 (5X)
 

iCOLON («6) (20)
 ADENOCARCINOMA, NOS, BETASTATIC 1 (5X)
 

URINARY SYSTEM
 

• KIDNEY (17) (38)
 LIPOMA 2 (IX)
 LIPOSARCOMA 1 (3X)
 MIXED TUHOR, MALIGNANT
 

HEMANGIOSARCOMA t (2X)
 

IDRINARY BLADDER (16) (25)
 PAPILLOMA, NOS 3 (7X)
 

ENDOCRINE SYSTEM
 

•PITUITARY	 (11) (23)
 CHROMOPHOBE ADENOMA i» (10X) 7 (30X)
 

•ADRENAL	 (16) (21)
 LIPOSARCOMA 1 (5X)
 

iTHYROID (18) (19)
 FOLLICOLAR-CELL ADENOMA
 

* NOMBER OF ANIMALS KITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIHALS NECFOPSIED
 

A-4
 

HIGH DOSE 

01-M009 

(28)
 

1 (IX)
 

(30)
 

1 (3X)
 

(29)
 

(28)
 

(28)
 

(ill)
 

2 (5X)
 

Rt?
 

Gtj
 

5	 (19X)
 

(29)
 

(19)
 

. - 1 J8X1 _
 
TABLE A1 (CONTINUED)
 

CONTROL(VEH ) LOU DOSE HIGH DOSE 

01-M001 01-M008 01-M009 

FOLLICOLAR-CELL CARCINOMA <* (8%) « (8X) 3 <6X) 

C-CELL ADENOM A 1 (2X) 1 (2X) 

C-CELL CARCINOM A 2 (4X) 3 <6X) 

•PARATHYROID	 (46) (21)
 ADENOMA, NOS 1 (2X)
 

•PANCREATIC ISLETS (46) (23) (30)
 

ISLET-CELL ADESOHA 1 (2%) 2 (9%) 2
 

REERODUCTIVE SYSTEM
 

'MAMMARY GLAND (49) (50) (50)
 ADENOMA, NOS 1 <2X)

 

ADENOCABCINOMA, NOS 2 (4X) 2 (IX)

 

FIBROADENOMA 1 <2X)

 

•PROSTATE	 (34) (15) (8)

 HEM1NGIOSARCOMA, METASTATIC 1 <3X)

 

*SEMINAL VESICLE (It9) (50) (50) 

HEMANGIOSARCOMA, METASTATIC 1 (2X) 

NEBVOOS SYSTE M 

• BRAIN (17) (2») (28)
 GLIOMA, NOS 1 (2X)
 

SPECIAL SENSE ORGAN S 

NONE 

BUSCULOSKELETAL SYSTEM
 

*SKELETAL MDSCLE (49) (50) (50)
 FIBROSARCOMA 1 (2X)
 

*HBSCLE OF BACK (49) |Sft) (50) 

HEMANGIOSARCOMA 1 (2X) 

*MOSCLE OF THORAX (49) (SB) (50) 

E ElliS G10S ABC2 MA 

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROPSIED
 
TABLE Al (CONCLUDED) 

CONTBOL(YEH ) L OW DOSE HIGH DOSE 

01-M001 01-M008 01-H009 

BODY CAVITIES
 

'ABDOMINAL CAVITY (50) (50)
 

LIPOMA 1 (2X)
 

ALL OTHEP SYSTEMS
 

'MULTIPLE ORGANS (50) (50)
 

HEMANGIOSARCOMA 1 (2%)
 

iNINAL DISPOSITION SUBSAKI
 

ANIMALS INITIALLY IN STUDY 59 50
 NATURAL DEATHS Sit 25
 

MORIBUND SACRIFICE t,
 SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERMINAL SACRIFICE 25
 A8IMAL HISSING
 

3 INCLUDES AUTOLYZED ANIMALS
 

TUBOB SUMMAR Y
 

TOTAL ANIMALS WITH PRIMARY TOMORS* 28 51 21
 

TOTAL PRIMARY TUMORS «1 2* 31
 

TOTAL ANIMALS WITH BENIGN TUMORS 13 W 11t
 TOTAL BENIGN TUMORS 17 IS 16
 

TOTAL ASISALS WITH BiUGNANT TUBCES 18 tS 12
 

TOTAL MALIGNANT TOMOES 21* H 15
 

TOTAL ANIMALS WITH SECONDARY TUMORS* 2 1
 

TOTAL SECONDARY TUMORS 6 1
 

TOTAL ANIMALS WITH TUMORS UNCERTAINBENIGN OR MULIGHANT
 

TOTAL UNCERTAIN TUMORS
 

TOTAL ANIMALS KITH TUBORS UNCERTAINPRIMARY OR METASTATIC
 TOTAL UNCERTAIN TUMORS
 

* PRIMARY TUBOBS: ALL TUBORS EXCEPT SECONDARY TUB08S
 

* SECONDARY TUMORS: METASTATIC TUMORS OR TUMORS INVASIVE INTO »N ADJACENT ORGAN
 

A-6
 
TABLE A2

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE RATS TREATED WITH DIOXATHION 

CONTROL (VEH)

01-F001

 LOW DOSE

 01-F010

 HIGH DOSE 

 01-F011 

ANIHALS INITIALLY IN STUD! 50

ANIMALS NECBOPSI6D 50

ASIBALS EXAMINED HIS1OPATHOLOGICALLY ** 50

 50

 50

 17

 50 

 50 

 48 

INTEGUMENTARY SYSTEB 

*S08CUT TISSDE

BASAL-CELL CARCINOBA

FIBROBA

FIBBOSA8COMA

LIPOHA

HEItANGIOSARCOMA

 (50)

 1 (2X) 

2 («*)

 1 (2%) 

3 (658) 

 (50)

 2 (If) 

1 (2X)

 (50) 

1 (2*) 

RESPIRATORY SYSTEH 

»LUNG

ADENOCARCINOBA, NOS. METASTATIC

 (50) jff) (l»3) 

1 (2*) 

HEBATOPOIETIC SYSTEM 

tCERVICAL LYBPH HODE

BALIG.LYBPHOBA, LYBPHOCYTIC TYPE

 (US)

 1 (2X) 

 (31) (28) 

CIRCDLATOFY SYSTEB 

*EMDOCARDIH»

SARCOBA, NOS

 (50) (31) (33) 

2 (6X} 

DIGESTIVE SYSTEB 

tLIVER

NEOPLASTIC NODULE

 (50)

 1 (2*) 

 (1)11) (HO) 

*PASCBEAS (50) (35) (29) 

* ROBBER Of AKISALS WITH TISSOE EXtHIKED

* IIOBBER OF ANIMAL S NECROPSIED 

"EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

 HICBOSCOPICALLY 

A-7 
TABf F A2 (CONTINUED) 

CONTROL(VEH ) LOW DOSE HIGH DOSE 

01-F001 01-T010 01-F011 

tSTOMACH (50) (39)
 OSTEOSARCOMA 1 <3X)
 

•DUODENUM	 (50) jfftj (32)
 

HEHANGIOSARCOMA <2X)
 

OSTEOSARCOMA
 

tILEOM (50) [34 j (32)
 

OSTEOSARCOMA 1 (3X)
 

URINARY SYSTEM
 

((KIDNEY (50) iWJ (37)

 

LIPOMA 1 (2X)

 

MIXED TUMOR, MALIGNANT 1 (2%}

 

HBMANGIOSARCOMA 2 (5X) 

HAMABTOMA +
 

((URINARY BLADDEP (U9) (32)

 

PAPILLOMA. NOS 1 (3S) 

ENDOCRINE SYSTEM
 

tFITUITAFY (50) i«ff) (39) 

CHROMOPHOBE ADENOMA 15 (30%) 9 (23X) 15 (38X) 

tTHYROID (50) (33) 

FOLLICULAR-CELL ADENOM A <3X)

 

FOLLICULAR-CELL CARCINOM A 1 (2X)

 

C-CELL ADENOM A 5 (10%) 3 (9X) 

C-CELL CARCINOM A 2 (6%) 2 (bX) 

IPANCREATI C ISLETS (50) (29) ISLET-CELL ADENOM A 1 (3X)

 

REPRODUCTIVE SYSTEM 

*MAMMAR Y GLAN D (50) (50) (50) 

ADENOMA , NOS 1 (2X ) 

ADENOCABCINOMA , NOS 2 (IX) 

FIBRO ADENOM A 15_I30S1 13_J26X.) 12_J2§Jl 

* NUMBE R OF ANIHAL S WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMAL S NECROPSIE D 

+ THIS IS CONSIDERED TO BF A BENIGN FORM 01 THE MALIGNANT MIXED TUMOR OF THE KIDNEY AND CONSISTS OF PROLIFERATIVE 

IIPOCYTES, TUBULAR STRUCTURES, FIBROBLASTS, AND VASCULAR SPACES IN VARYING PROPORTIONS 
TABLE A2 (CONTINUED) 

CONTROL (VEH)

01-F001

 LOH DOSE

 01-F010

 HIGH 0OSJS 

 01-F011 

HUTERUS

LEIOMYCMA

ENDOHETRIAL STROMAL POLYP

iOVARY

CARCINOMA.NOS

LOTEOBA

GRANDLOSA-CELL TOHOR

 (1»9)

 4 (85i)

 (1(9)

 1 (2X) 

1 (2X) 

 f3«J

 2 (6X)

 (34)

 (31) 

1 (3X) 

1 (3X) 

 (31) 

1 (3X) 

NZBVOOS SYSTEM 

NONE 

SPECIAL SENSE ORGANS 

NONE 

MOSCULOSKELETAL SYSTEM 

NONE 

BODY CAVITIES 

•ABDOMINAL VISCERA

HEMANGIOSAECOHA

 (50)

 1 (2%) 

 (5S} (50) 

ALL OTHER SYSTEMS 

THORACIC CAVITY 

FIBBOSA8COMA 1 

ANIMAL DISPOSITION SOMHARI 

ANIMALS INITIALLY IN STUDY $tf 50

NATURAL DEATHS W 19

MORIBUND SACRIFICE

SCHEDDLED SACRIFICE 

ACCIDENTALLY KILLED 

TERMINAL SACRIFICE 3$ Jl

ANIMAL MISSING 

j_ INCLUDES,AUTQLYZED AMIMALS 

t NUMBER OF ANIMALS HITH TISSUE EXAMINED MICROSCOPICALLY 

» NUMBER OF ANIMALS NECROPSIED 

 50 

 15 

1 

 34 

A-9 
TABLE A2 (CONCLUDED)
 

CONTROL (VIH) LOW DOSE HIGH DOSE 

01-F001 01-P010 01-F011 

TUBOF SUMMARY
 

1OTAL ANIMALS WITH PRIMARY TUMORS* 36 §7 29
 

TOTAL PRIMARY TUBORS 56 SI H5
 

TOTAL ANIMALS WITH BENIGN TUBORS 31 Z5 26
 TOTAL BENIGN TUHORS 11 88 33
 

TOTAL ANIMALS WITH MALIGNANT TUMORS 9 % 9
 TOTAL MALIGNANT TDMOBS 10 J) 12
 

TOTAL ANIMALS «ITH SECONDARY TUKOES* 1
 

TOTAL SECONDARY TUMORS 1
 

TOTAL ANIMALS WITH TOBORS UNCERTAINBENIGN OP BALIGNANT 2
 

TOTAL UNCERTAIN TUMORS 2
 

TOTAL ANIBALS WITH TDMOBS UNCEBTAINPRIMABY OR BETASTATIC
 TOTAL UNCERTAIN TUMORS
 

* PRIMARY TOMOBS: ALL TUBORS EXCEPT SECONDARY TUMOBS
 * SECONDARY TUMORS: METASTATIC TUMORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 

A-IO
 
APPENDIX B
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS
 

IN MICE TREATED WITH DIOXATHION
 

TABLE Bl SUMMARY OF THE INCIDENCE OF NEOPLASMS IN MALE MICE TREATED WITH DIOXATHION 

CONTROL (VEH)

02-H011 LOK DOSE 02-H012

 HIGH DOSE 

 02-8013 

ANIMALS

ANIMAL S

ANIMAL S

ANIMALS

 INITIALLY IN STUDY 3f

 MISSING

 NECROPSIBD 20

 EXAMINE D HISTOPATHOLOGICALLY ** 19

 ff

 t

 49

 19

 Sft 

1 

 U9 

 19 

INTEGUHENTARY SYSTEM 

•SKIN

SQUAMOUS CELL CARCINOMA

 (2$t (1(9)

 1 (2%) 

 (U9) 

*SUBCUT TISSUE

FIBSOSAHCOMA

OSTEOSARCOMA

 t?W

 1 (5X)

 1 (5X) 

 («9)

 5 (10X)

 (19) 

3 (6X) 

RESPIRATORY SYSTEM 

ILUNG

ALVEOLAR/BRONCHIOLAR ADENOMA

ALVEOLAR/BRONCHIOLAR CARCINOMA

 (16)

 1 (6X)

 (17)

 1 (6X)

 (19) 

3 (16X) 

1 (5X) 

HiBATOPOIETIC SYSTEM 

•MULTIPLE ORGANS

GRANOLOCYTIC LEUKEMIA

 (Bfl) v (19) (49) 

1 (2X) 

ILYMPH NODE

BALIG.LYHPHOMA, HISTIOCYTIC TYPE

 (15) (13)

 1 (8X) 

 (12) 

CIRCULATORY SYSTEM 

NONE 

DIGESTIVE SYS1EM 

ILIVER (17) («9) (49) 

t NUMBE R OF ANIMAL S WITH TISSUE EXAMINE D * NOSBER OF ANIMALS SECROPSIED 

"EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

 MICROSCOPICALLY 

B-3 
TABLE Bl (CONTINUED) 

CONTROL (YEH) LOB DOSE HIGH DOSE 

02-H011 02-M012 02-H013 

HEPATOCELLOLAR CARCINOM A 4 (21*) 1 (8*) 5 (10X) 

FIBROSARCOMA , BETASTATIC 1 (2%) 

HEMANGIOSARCOM A 1 (2X) 

URINAR Y SYSTEM 

NON E 

ENDOCRINE SYSTEM 

HONE 

BEPRODUCTIV E SYSTEM 

NONE 

NERVOU S SYSTEM 

NON E 

SPECIAL SENSE ORGAN S 

NON E 

MUSCOLOSKELETAL SYSTEM 

•SKELETAL	 MUSCLE {$0} (t9) (t9)
 

FIBFOSARCOMA 1 (2X)
 

BODY CAVITIES
 

*ABDOMINAL CAVITY (29) (H9) (<»9)
 

LIPOMA 1 (2X) 1 (2X)
 

ALL OTHER SYSTEMS
 

NOSE
 

t NUMBER OF ANIMALS HITH TISSOE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECFOPSIED
 

B-4
 
TABLE Bl (CONCLUDED)
 

CONTROL(VEH) LOU DOSE HIGH DOSE
 

02-M011 02-B012 02-M013
 

ANIMAL DISEOSITION SUBMARY
 

ANIMALS INITIALLY IN STUDY M 50
 

NATURAL DBATH9 * 1<4
 

MORIBUND SACRIFICE
 

SCHEDULED SACRIFICE
 ACCIDENTALLY KILLED
 TERMINAL SACRIFICE 1i 35
 

ANIMAL MISSING 1
 

a INCLUDES AUTOLYZED ANIMALS
 

tUBOR SUMMARY
 

TOTAL ANIMALS WITH PRIMARY TUMORS* 7 10 13
 

TOTAL PHIMARY TUMORS 8 V3 17
 

TOTAL ANIMALS BITH BENIGN TUMOBS 2 1 ft
 TOTAL BENIGN TUMORS 2 1 5
 

TOTAL ANIMALS WITH MALIGNANT TUBOSS 6 4 11
 

TOTAL MALIGNANT TUMORS 6 11= 12
 

TOTAL ANIMALS WITH SECONDARY TUMORS* $
 TOTAL SECONDARY T0BORS %
 

TOTAL ANIMALS KITH TDMORS UNCERTAIN­ BENIGN OR MALIGNANT
 

TOTAL UNCERTAIN TDMORS
 

TOTAL ANIMALS BITH TUBORS DNCE8TAI1­

EEINABY OR METASTATIC
 

TOTAL UNCERTAIN TUBORS
 

* PRIMARY TUMOBS: ALL TUMOBS EXCEPT SECONDARY TUMORS
 

t SECONDARY TUMORS: MZTASTATIC TUMORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 

B-5
 
TABLE B2

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE MICE TREATED WITH DIOXATHION 

CONTROL (VEH) LOU EOSE HIGH DOSE 

02-F011 02-FOU 02-F015 

ANIMAL S INITIALL Y I N STUDY 20 50 50 

ANIMAL S MISSIN G 1 \ 

ANIMAL S NECROPSIE D 19 S0 $% ANIMAL S EXAMINE D HISTOPATHOLOGICALLY ** 18 SB m 

INTEGUMENTAR Y SYSTEM 

*SUBCUT TISSUE (19) (50) («9) 

MYXOSARCOM A 1 <2X ) 

RESPISATOPY SYSTEM 

ULUN G (18) (15) (12) 

ALVEOLAR/BRONCHIOLA R ADENOM A 1 (7X) 1 (8X) 

HEMATOPOIETIC SYSTEM 

*MULTIPLE ORGANS (19) (50) fJtft 

MALIG. LYMPHOMA , HISTIOCYTIC TYPE 1 <5X) 

*ABDOMINA L CAVITY (19) (50) f»J 

MALIGNAN T LYMPHOMA , NOS 1 (2%) 

*MESENTERIC L. NODE (17) (10) (12) MALIGNAN T LYMPHOMA , MIXED TYPE 1 (6X) 

«LIVE H (18) (50) (»8) 

MALIG. LYMPHOMA , LYMPHOCYTIC TYPE 1 <2X) 1 (2X) 

MALIG . LYMPHOMA , HISTIOCYTIC TYPE 1 (2X) 

IUTERUS (18) (16) (21) 

MALIG . LYMPHOMA , HISTIOCYTIC TYPE 1 (6«) 

CIRCULATORY SYSTEM 

NON E 

I NUMBE R OF ANIMAL S WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMAL S SECROPSIED 

"EXCLUDES PARTIALLY ADTOLYZED ANIMALS 

B-6 
TABLE B2 (CONTINUED) 

CONTROL(VEH)

02-F011

 LOB DOSE

 02-F01H

 HIGH DOSE 

 02-F015 

DIGESTIVE SYSTEM 

*LIVER

HEPATOCELLOLAR CARCINOMA

HEaANGIOSABCOHA

 (18) (50)

 1 (2X) 

 (<48) 

1 (2X) 

OHINAH Y SYSTEH 

NONE 

ENDOCRINE

NONE 

 SYSTEM 

REPRODUCTIVE SYSTEM 

*BAMBARY GLAND

ADENOCARCINOMA. NOS

 (19) {SO} (149) 

2 (U») 

NERVOUS SYSTEH 

NONE 

SPECIAL SENSE ORGANS 

NONE 

HUSCULOSKELETAL SYSTEM 

NONE 

BODY CAVITIES 

NONE 

AL1 OTHER SYSTEMS 

NONE 

* NUMBER OF ANIMALS KITH TISSUE EXAMINED

* NUMBER OF ANIMALS NECROPSIED 

 MICROSCOPICALLY 

i-r
 
TABLE B2 (CONCLUDED)
 

CONTROL (VEH) LOU DOSE HIGH DOSE
 

02-F011 02-F01* 02-F015
 

ANIMAL DISPOSITION SUMMARY
 

ANIMALS INITIALLY IN STUDY 20 f0 50
 NATURAL DEATHS 1 1 11
 

MORIBUND SACRIFICE
 

SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERMINAL SACRIFICE 18 4| U5
 

ANIMAL HISSING 1 1
 

8 INCLUDES AUTOLYZED ARIMALS
 

TUHOS SUMMARY
 

TOTAL ANIMALS »ITH PRIMARY TUMORS* 2 tr 6
 TOTAL PRIMARY TUMORS 2 6 i
 

TOTAL ANIMALS WITH BENIGN TUMORS f
 *
 TOTAL BENIGN TUMORS 1 \
 

TOTAL ANIMALS WITH MALIGNANT TOMOFS 2 >
 *
 TOTAL MALIGNANT TUMORS 2 1 s
 

TOTAL ANIMALS KITH SECONDARY TUMORS!
 

TOTAL SECONDARY TUMORS
 

TOTAL ANIMALS WITH TUMORS UNCEBTAINBENIGN OB MALIGNANT
 

TOTAL UNCERTAIN TUHORS
 

TOTAL ANIMAL S KITH TUMORS UNCERTAINPRIMAB Y OB MEMS1ATIC

 

TOTAL UNCERTAIN TUMORS 

* PBIMARY TUMORS: ALL TUMORS EXCEPT SECONDABY TUMOBS
 

* SECONDABY TUHORS: MITASTATIC TUMORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 
APPENDIX C
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN RATS TREATED WITH DIOXATHION
 

TABLE Cl

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN MALE RATS TREATED WITH DIOXATHION 

CONTROL(VEH) LOW DOSE HIGH DOSE
 

01-M001 01-H008 01-M009
 

ANIMALS INITIALLY IN STUDY 50 5,fi JO
 

ANIMALS NECROPSIED 19 80 $8
 

AHIHAtS EXAMINED HISTOPATHOLOGICALLI ** <(9 50 »9
 

IHTEGUMENTAHY SYSTEM
 

*SKIN f<»9) (50) (50)
 

EPIDERMAL INCLUSION CYST 1 (2X)
 

INFLAMMATION, NOS 1 (2X) 2 (tX)
 

*SUBCUT TISSUE (09) (50) (50)
 

ABSCESS, NOS 1 (2%) 1 (2%)
 

RESPIBATOBY SYSTEH
 

ITRACHEA (*}
 

INFLAMMATION, NOS « (100%)
 

ILONG (U9) (39) (HO)
 

ATELECTASIS 1 (3%)


PNEUMONIA, CHRONIC HURINE 20 (41%) 19 (t9K) 17 («3X)
 

HEMATOPOIETIC SYSTEM
 

tSPLEEN (U7) (23) (29)
 

PIBROSIS 1 (2X)
 HEHATOPOIESIS 1 (2X) 3 (13S) 2 (7X)
 

*MESENTERIC L. NODE (H5) (18) (21}
 

CYST, HOS 1 (2X) 1 (6S)
 INFLAMMATION, NOS 1 (6X)
 

CIRCULATOEY SYSTEM
 

• MYOCARDIUM (47) (2"») (28)
 

* NUMBER OF ANIMALS BITH TISSUE EXAMINED MICBOSCOPICALLY
 

* NUMBER OF ANIMALS NECROPSIED
 

"EXCLUDES PARTIALLY AUTOLYZED ANIMALS
 

C-3
 
TABLE Cl (CONTINUED) 

CONTROL (VEH) 

01-H001 

LOU COSE 

01-8008 

HIGH DOSE 

01-M009 

FIBROSIS 

DEGENERATION, NOS 

1 <2X) 4 (17X) 3 (11X) 

•ENDOCARDIU M 

HYPERPLASIA , NOS 

(47) (2«) 

1 (»X) 

(28) 

1 (tX) 

*AORTA 

PERIARTERITI S 

ARTERIOSCLEROSIS, NOS 

(49) 

4 (8X) 

(50) 

1 (2X) 

(50) 

DIGESTIVE SYSTEM 

•LIVES 

DILATATION, NOS 

CYST, NOS 

INFLAMMATION , NOS 

METAMORPHOSIS FATTY 

HYPERPLASIA, NOS 

(49) 

2 (4X) 

3 (6X) 

3 (6X) 

5 (10X) 

(37) 

1 <3X) 

2 (5X) 

1 (3X) 

7 (19X) 

1 (3X) 

(44) 

3 (7X) 

3 (7X) 

*BILE DUCT 

HYPERPLASIA, NOS 

(49) 

3 (6X) 

(50) 

5 (10X) 

(50) 

1 (2X) 

•PANCREAS 

PERIARTERITIS 

DEGENERATION, NOS 

ATROPHY, NOS 

(46) 

5 (11X) 

(23) 

3 (13X) 

C»X) 

(30) 

1 (3X) 

•ESOPHAGUS 

INFLAMMATION. NOS (1) 

1 (100X) 

•STOMACH 

INFLAMMATION. NOS 

ULCER, FOCAL 

CALCIUM DEPOSIT 

CALCIFICATION, NOS 

(46) 

1 <2X) 

(29) 

1 (3X) 

1 <3X) 

7 (24X) 

(29) 

3 (10X) 

2 (7X) 

1 <3X) 

•LARGE INTESTINE 

NEMATODIASIS 

(46) f2$] (28) 

1 («*) 

•COLON 

INFLAMMATION, NOS 

PARASITISM 

(46) 

1 (2X) 

(20) (28) 

1 (4X) 

U8INARY SYSTEM 

•KIDNEY 

. HIDRONEPHROSIS . . , , 

(47) (38) 

J-J3JJ i u

(41) 

 „.,..,-. ^ ... , L^. 

* NUMBER OF AMIMALS BITH TISSUE EXAHINED MICROSCOPICALLY 

* NUMBER OF ANIMALS NF.CROPSIBD 
TABLE Cl (CONTINUED) 

"
 

PYELONEPHRITIS, NOS
 

PYONEPHROSIS
 

ABSCESS, NOS
 

INFLAMMATION, CHRONIC
 

CALCIUM DEPOSIT
 

•URINARY	 BLADDER
 

INFLAMMATION, NOS
 

ENDOCRINE SYSTEM
 

•PITUITARY
 

CYST, NOS
 

•ADRENAL
 

CALCIUM DEPOSIT
 

ANGIECTASIS
 

•THYROID
 

CYST, NOS
 

FOLLICOLAR CYST, NOS
 

HYPEHPLASIA, PAPILLARY
 

HYPERPLASIA, C-CELL
 

HYPERPLASIA, FOtLICULAR-CELL
 

• PARATHYROID
 

HYPERPLASIA, NOS
 

REPRODDCTIVE SYSTEM
 

*MA»MARY GLAND
 

GALACTOCELE
 

CYST, NOS
 

•PROSTATE
 

INFLAMMATION, NOS
 

•SEMINAL	 VESICLE
 

INFLAMMATION, NOS
 

HYPERPLASIA, NOS
 

•TESTIS
 

ATROPHY*. NOS _ _
 

* NUMBER OF ANIMALS KITH TISSUE

* SOMBER OF ANIMAL S NECROPSIED 

HIGH DOSE
 

01-S009
 

1 (2X)
 

36 (88X)
 

3 (7X)
 

(26)
 

1 (4X)
 

(27)
 

1 (4X)
 

(29)
 

1 (3X)
 

5 (17X)
 

(49)
 

2 (4X)
 

1 (2%)
 

3 (6X)
 

(21)
 

5 (24X)
 

(50)
 

1 (2X)
 

w
 

(50)
 

1 (2X)
 

1 (2X)
 

(27)
 12.J37S1 _ _ _
 .
 

CONTROL (VEH)
 

01-H001
 

2 (IX)
 

1 (2X)
 

1 (2X)
 

37 (79X)
 

(«)
 

1 (2*)
 

(41)
 

1 (2X)
 

****
 

8 (17X)
 

(18)
 

1 (2X)
 

1 <2X)
 

4 (8X)
 

(46)
 

2 (4X)
 

(49)
 

1 (2X)
 

1 (2X)
 

(34)
 

9 (26X)
 

(49)
 

1 (2X)
 

(44)
 

9 (20X)
 

LOB DOSE
 

01-M008
 

30 (79X)
 

3 (8X)
 

(25)
 

(23)
 

(21)
 

5 (24X)
 

09)
 

1 (2X)
 

3 (6X)
 

(27)
 

7 (26X)
 

(50)
 

1 (2X)
 

(15)
 

1 (7X)
 

(50)
 

1 <2X)
 

(20)
 

9_J41Xi
 

 EXAHI1IED BICflOSCOPICALLY 

C-5 
TABLECl (CONTINUED) 

CONTROL(VEH ) LOU DOSE HIGH DOSE 

01-H001 01-M008 01-M009 

'EPIDIDYMIS (49) (50) {53} 

ATROPHY, SOS 1 (2%) 2 (4*) 

NERVOUS SYSTEM
 

NONE
 

SPECIAL SENSE ORGANS
 

*EYE (49) (50) f$B*
 

PHTHISIS BBLBI 1 (2%)
 

*EYE/LACRIMAL GLAND (49) (50) (50)
 

INFLAMMATION, NOS 2 (1%)
 

*HiRDERIAN GLAND (49) (50) ISf}
 

INFLAMMATION, NOS 1 (2%)
 

MUSCULOSKELETAL SYSTEM
 

*SKULL (49) (50) <50)
 

INFLABHATION, NOS 1 (2%) 1 (2%)
 

FIBEOSIS 1 (2%) 1 (2X)
 

*SKELETAL MUSCLE (<»<>) (50) fSfil
 

DEGENERATION, NOS 1 (2%)
 

BODY CAVITIES
 

*FERICAFDIUB (19) (50) (Slj
 

ISFLAKHATION, NOS 5 (10K) 3 (6%)
 

• MESENTERY (49) (50) (50)
 

PEHIARTERITIS 2 (4*)
 

ALL OTHEB SYSTEMS
 

NONE
 

* NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROPSIED
 
TABLE Cl (CONCLUDED) 

CONTROL(VEH ) LOU DOSE HIGH DOSE 

01-M001 01-M008 01-M009 

SPECIAL MORPHOLOGY SUMMAR Y 

NO LESION BEPORTED J 3 

AUTO/NECROPSY/HIS1O PERF I 

AUTO/NECROPSY/NO HISTO 1 

AOTOLYSIS/NO NECROPSY 1 

# NUMBE R OF ANIMAL S HITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMALS NECROPSIED 

CKF 
TABLE C2

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS 

IN FEMALE RATS TREATED WITH D1OXATHION 

CONTROL (VEH) LOU COSE HIGH DOSE 

01-F001 01-P010 01-F011 

ANIMAL S INITIALL Y IN STODY 50 50 50 

JlltlliaiS NEC80PSIED 50 50 50 

ANIMAL S EXAMINE D HISTOPATHOLOGICALLY ** 50 U7 18 

INTEGUMENTARY SYSTEM
 

*SKIN (50) (50) (50)
 EPIDERMAL INCLUSION CYST 1 (2X)
 

INFLAMMATION, NOS 1 (2X) 1 (2X) 1 (2X)
 

ACANTHOSIS 1 (2X)
 

*SUBCUT TISSUE (50) (50) (50)
 

ABSCESS, NOS 1 (2X)
 

RESPIRATORY SYSTEM
 

• TRACHEA (5) 

INFLAMMATION , NOS 5 (100X) 

ILUN G (50) (39) {«) 

IIJFLAMHATION , NOS 1 (2X) 

PNEUMONIA , CHRONIC (IODINE 15 (30%) 19 (49X) 18 (12X) 

HYPEHPLASIA , ADENOMATOUS 1 (2X) 

HIMATOPOIETIC SYSTEM 

»BOSE RAEBO1I (SO) (33) tl1) 

METAMORPHOSI S FATTY 1 (2X) 

ISPLEEN (50) (3t) (35) 

HEMORRHAG E 1 (3X) 

HEMATOPOIESIS 5 (10%) 2 (6%) 7 (20X) 

CIRCULATORY SYSTEM 

• MYOCARDIUM (50) (3U) (33) 

* NUMBE R OF ANIMAL S KITH TISSUE EXAMINED MICBOSCOPICA1LY 

* NUMBE R OF ANIMAL S NECROPSIED 

"EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

C-8 
TABLE C2 (CONTINUED)
 

HIGH DOSE
 01-F011
 

(33)
 

(50)
 

(i»0)
 

1 (3X)
 

1 (3X)
 

(50)
 

1 (2X)
 

1 (2X)
 

(29)
 

(39)
 

1 (3X)
 

3 (8X)
 

(29)
 

(29)
 

(37)
 

1 (3X)
 

1 (3X)
 

1 (3X)
 

21 (57 X)
 

1-I1S1
 _.
 

DEGENERATION, NOS
 

tENDOCARDIUM
 

HYPER PL* Sid, NOS
 

*AOFTA
 

ARTERIOSCLEROSIS, NOS
 

DIGESTIVE SYSTEM
 

IIIVER
 

INFLAMMATION, NOS
 

METAMORPHOSIS FATTY
 

FOCAL CELLULAR CHAHGE
 

AHGIECTASIS
 

*BILE DUCT
 

DILATATION, NOS
 

HYPERPLASIA, NOS
 

tEANCREAS
 

PERIARTERITIS
 

# STOMACH
 

INFLAMMATION, NOS
 

ULCEB, FOCAL
 

CALCIUH DEPOSIT
 

tLARGE INTESTINE
 

PARASITISM
 

•COLON
 

PARASITISM
 

URINARY SYSTEM
 

tKIDNEY
 

MINERALIZATION
 CYST, NOS
 

PYELONEPHRITIS, NOS
 

INFLAMMATION, SUPPUEATIYE
 

INFLAMMATION, CHRONIC
 

CALCIUM DEPOSIT
 

CONTROL (VEH) LOB DOSE
 

01-F001 01-F010
 

2 (4X) U (12X)
 

(50)	 (34)
 

1 (2X) 1 OX)
 

(50)	 (50)
 

1 (2X) 1 (2X)
 

(50)	 (11)
 

4 (8%)
 

1 (2%)
 

1 (2%)
 

1	 (2X)
 

(50)	 (50)
 

1 (2X)
 

2 (4%)
 

(50)	 (35)
 

1 (3X)
 

(50) (37)
 

5 (10X) 1 (3X)
 

1 (2X) 1 (3X)
 

(19)	 (3M)
 

1 (2X)
 

(19) (31)
 

U	 (12X)
 

(50) («|
 

1	 (2X)
 

23 (1*6%) 25 (63X)
 

4 J1Q81
 

I	 NUMBER OF ANIMALS BITH TISSUE EXAMINED MICROSCOPICALLY
 

*	 NUMBER OF ANIMALS NECROPSIED
 
TABLE C2 (CONTINUED) 

CONTROL (VEH) LOB DOSE HIGH DOSE 

01-F001 01-F010 01-F011 

•KIDNEY/PELVI S (50) ftO) (37) 

CALCIUM DEPOSIT 2 (5X)

 

IURINAR Y BLADDER (<t9) (3K) (32) 

INFLAMMATION , NOS 1 (3X) 

ENDOCRIN E SYSTEM 

• PITUITAR Y (50) (HO) (39) 

ANGIECTASIS 1 (2X)

 

IADRENA L (50) (37) (33) 

ANGIECTASI S 17 (3i»X) 6 (16%) 5 (15X) 

ITHYROI D (50) (33) (31)

 

HYPERPLASIA , NOS 1 (3X) 

HYPERPLASIA . C-CELL 2 <4X)

 

HYPERPLASIA , FOLLICOLAR-CELL 2 (HX) 3 (9X)

 

REPRODUCTIV E SYSTEM 

*HAMMAR Y GLAN D (50) (50) KSW

 GALACTOCELE 1 (2X)

 

HYPEEPLASIA , NOS 1 (2%) 1 (2X)

 

tUTERO S C*9) (31) (31) HYDROMETR A 9 (18X) 3 (9X) 2 (6X) INFLAMMATION , DOS 2 (U%) 2 (6X) 

IUTERTJS/ENDOMETRIU M (K9) (3«) (31)

HYPERPLASIA , CYSTIC 3 (6*) 2 (6X) 1 (3X) 

IGVAB Y («9) (31) (31)

 CYST, NOS 2 (<tX) 1 (3X)

 

NERVOU S SYSTEM 

NONE 

SPECIAL SENS E ORGAN S 

*EYE (50) tsor (50) __ SYNECHIA^ NOS _ _ _ 1 J2X1_ 

* NUMBER OF ANIMALS KITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROPSIED
 

C-B
 
TABLE C2 (CONCLUDED)
 

CONTROl(VEH) LOU DOSE HIGH DOSE 

01-F001 01-F010 01-F011 

CATARACT 1 (8X) 4 (8X) 

*IYE/CORNEA (50) (50) 

FIBROSIS 1 (2%) 

CYTOPLASMIC VACUOLIZATIO N 1 (2X) 

•EYE/RETINA (50) (50) 

ATROPHY, NOS « (8X) 

*EYE/CRYSTALLINE LENS (5«3 (50) (50)
 CALCIUM DEPOSIT 1 <2X)
 

*HARDERIAN GLAND (50) (50) (50)
 

INFLAMMATION, NOS 1 (2%)
 

MUSCULOSKELETAL SYSTEM
 

NONE
 

BODY CAVITIES
 

*PERITONEUM (Sf) (50) (50)
 

INFLAMMATION, NOS 1 (2%)
 

*FERICARDIUM (501 (50) (50)
 

INFLAMMATION, NOS H (8*)
 

ALL OTHER SYSTEMS
 

NONE
 

SPECIAL MORPHOLOGY SUMMARY
 

NO LESION REPORTED 1 I »
 

NECROPSY PERF/NO HISTO PERFORMED 2
 AUTO/NECROPSY/NO HISTO 1 2
 

* NUMBER OF ANIMALS KITH TISSUE EXAMINED MICROSCOPICAILY
 

* NUMBER OF ANIMALS NECROPSIED
 

C-ll 

APPENDIX D
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN MICE TREATED WITH DIOXATHION
 

TABLED1

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN MALE MICE TREATED WITH DIOXATHION 

CONTROL (VEH)

02-H011

 LOU DOSE

 02-M012

 HIGH DOSE 

 02-M013 

ANIMALS INITIALLY IN STUDY 20

ANIMALS MISSING

ANIMALS NECEOPSIED 20

ANIMALS EXAMINED HISTOPATHOLOGICALLY ** 19

 50

 1

 f»

 »9

 50 

1 

W 

 1>9 

INTEGUMENTARY SYSTEM
 

*SKIN (20) (19) («9)
 

EPIDERMAL INCLUSION CYST 1 (5X) 1 (2X)
 

INFLAMMATION, NOS 1 (2%) 2 (<IX)
 

INFLAMMATION, CHBONIC 2 (10X) 1 (2X)
 

*SUBCUT TISSUE (20) (U9) (19)
 

ABSCESS, NOS 1 (2«)
 

EESPIBATOEY SYSTEM
 

• LUNG (16) (17) {t?|
 

INFLAMMATION, FOCAL 1 (6X)
 

PNEUMONIA, CHRONIC MURINE 1 (6X)
 

HEMATOPOIETIC SYSTEM
 

#SPLEEN (16) (15)
 INFLABMATION, NOS 1 (7»)
 AMYLOIDOSIS 3 (19X) (9*) 2 (13X)
 HYPERPLASIA, NOS 1 (7X)
 HENiTOPOIESIS <9X) 2 (13X)
 

ILYMPH NODE till (13) (12)
 ISFLAMHATION, NOS 1 (8%)
 HEMATOPOIESIS 1 (8»)
 

tMISENTERIC L. NODE (13) (12)
 

INFLAMMATION, NOS 2 (15X) 1 (8X)
 HEHATOPOIESIS 1 (8X)
 

CIECOLATORY SYSTEM
 

•HEART (16) (10) (10) 

iflltQlDOSIS 

* NOMBER OF ANI8ALS KITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMALS NECROPSIED 

**EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

D-3 
TABLE Dl (CONTINUED) 

DIGESTIVE SYSTEM
 

OLIVER
 

CYST, NOS
 

INFLAMMATION, NOS
 

NECROSIS, NOS
 

AMYLOIDOSIS
 

METAMORPHOSIS FATTY
 

HYPERPLASIA, NODULAR
 

HYPEEPLASTIC NODULE
 

HYPEHPIASIA, FOCAL
 

ANGIECTASIS
 

tEANCREAS
 

INFLAMMATION, NOS
 

AMYLOIDOSIS
 

•LARGE INTESTINE
 

NEMATODIASIS
 

*BECTUM
 

INFLAMMATION, NOS
 

URINAR Y SYSTEM 

IKIDNEY
 

HYDRONEPHROSIS
 

POLYCYSTIC KIDNEY
 

PYELONEPHRITIS, KOS
 

INFLAMMATION, CHRONIC
 

PERIARTERITIS
 

AMYLOIDOSIS
 

CALCIUM DEPOSIT
 

iURINARY BLADDER
 

INFLAMMATION, CHRONIC
 

ENDOCRINE SYSTEM
 

IADPENAL
 

AMYLOIDOSIS 

• PARATHYROI D 

AMYLOIDOSIS_. 

I NUMBE R OF ANIMAL S KITH TISSUE

« NUMBE R OF ANIMAL S NFCROPSIED 

HIGH DOSE
 

02-8013
 

(19)
 

1 <2X)
 

1 (2X)
 

7 (11X)
 

1 (2*)
 

9 (18X)
 

1 (2X)
 

2 (IX)
 

(10)
 

(10)
 

(19)
 

1 (2X)
 

(18)
 

1 (6X)
 

1 (6X)
 

2 (11X)
 

3 (17X)
 

(11)
 

(10) 

(10) 

CONTROL (VEH) 

02-H011 

(17)
 

2 (12X)
 

1 (6X)
 

1 16%)
 

(16)
 

1 (6X)
 

(15)
 

2 (13X)
 

(20)
 

(19)
 

8 (12X)
 

1 <5X)
 

2 (11X)
 

1 <5X)
 

(15)
 

1 (7X)
 

(16)

2 (13X) 

(6)

i_J17Sl 

LOW DOSE
 

02-BO 12
 

(Wj
 

1 <2X)
 

3 (6X>
 

3 (6X)
 

1 (2X)
 

(11)


1 <9X)
 

(10)
 

(19)
 

|1S|
 

2 (13X)
 

2 (13X)
 

3 (19*)
 

(10)
 

 (10) 

 (10) 

 EXAMINE D BICROSCOPICALLY 
TABLE Dl (CONCLUDED)
 

CONTROL (VEH)

02-H011

 LOU COSE

 02-H012

 HIGH DOSE 

 02-N013 

REPRODUCTIVE SYSTEH 

#TESTIS

ATROPHY, NOS

»EPIDIDYMIS

GRANBLOHA, SPERMATIC

 (16)

 1 (6%) 

 (20)

 1 (5%) 

 (12)

 (M9)

 (10) 

 (»9) 

NEPVOUS SYSTEH 

NONE 

SPECIAL SENSE ORGANS 

NONE 

MUSCULOSKELETAL SYSTEM 

NONE 

BODY CAVITIES 

NONE 

ALL OTHER SYSTEMS 

NONE 

SPECIAL MORPHOLOGY SUMMARY 

NO LESION REPORTED ft 25

ANIMAL MISSING/NO NECROPSY 1

AUTO/NECROPSY/NO HISTO 1 

# NUMBER OF ANIMALS WITH TISSUE IXABIHED MICBOSCOPICALLY 

* NUMBER OF ANIMAL S NECROPSIED 

 13 

1 

D-5
 
TABLE D2

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS 

IN FEMALE MICE TREATED WITH DIOXATHION 

CONTROL (VEH)

02-F011

 LOU DOSE

 02-F014

 HIGH DOSE 

 02-F015 

ANIflAIS INITIALLY IN STUDY 20

ANIMALS HISSING 1

ANIMALS NECROPSIED 19

ANIMALS EXAMINED HISTOPATHOLOGICALLY *, 18

 50

 50

 50

 50 

1 

 t9 

 18 

INTEGUMENTARY SYSTEM
 

NONE
 

RESPIRATORY SYSTEM
 

• LONG (18) (15) (12)
 

INFLAHMATION, FOCAL 1 (6X)
 

PNEUMONIA, CHRONIC MURINE 1 (7X)
 

HEHATOPOIETIC SYSTEM
 

• SPLEEN (18) (12) (11)
 

HEMATOPOIKSIS 1 (8%)
 

CIRCULATORY SYSTEM
 

NONE
 

DIGESTIVE SYSTEM
 

tllVER (18) (U8) 

INFLAMMATION, FOCA1 1 <2X) NECROSIS, FOCAL 1 (2%) ANGIECTASIS 1 <6X) 1 (2X) 2 («X) 

• PANCREAS (17) (10) (10)
 ATROPHY, NOS 1 (6X)
 

•STOMACH (18) (11) (10)
 

I NUMBER OF ANIMAL S KITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBER OF ANIMAL S NECROPSIED 

"EXCLUDES PARTIALLY AUTOLYZED ANIMALS 
TABLE D2 (CONTINUED) 

CONTROL (VEH ) LOH DOSE HIGH DOSE 

02-F011 02-F011 02-F015 

URINAR Y SYSTEM 

IKIDNE Y (18) (10) (11) LYMPHOCYTIC INFLAMMATOR Y INFILTR 1 OX) 

ENDOCRIN E SYSTEM 

• ADRENA L (18) (10) (10)

 

HYPERPLASIA , NOS 1 (10X)

 

REPRODUCTIVE SYSTEM 

*MAMMAR Y GLAN D (19) (50) («9)

 

CYST, NOS 1 (2X)

 

IUTERUS (18) (16) (21) 

HYDROMETR A 2 (13X) 2 (10X) 

INFLAMMATION , NOS 1 (6X) 

INFLAMMATION . SUPPURATIV E 1 (6X> 

IUTERUS/ENDOMBTRIUM (18) (16) (21) 

HYPERPLASIA, CYSTIC 2 (11X) 3 (19X) 8 (38X) 

tCVARY/OVIDUCT (18) (16> (21) 

CYST, NOS 1 (5%) 

INFLAMMATION , NOS 1 <5X) 

*OVARY (18) ft!) (12) 

CYST. NOS 1 (8X) 1 (8X) 

INFLAMMATION , HOS 1 (8X) 

INFLAMMATION , SUPPURATIV E 2 (11X) 

NERVOUS SYSTEM
 

NONE
 

SPECIAL SENSE ORGANS
 

*EYE (19) (50) (U9)
 

HYPOPLASIA, NOS 1 (2X)
 

MOSCULOSKELETAL SYSTEM
 

NONE
 

* NUMBER OF ANIMALS KITH TISSDE EXAMINED MICROSCOPICALLY
 

* NDHBER OF ANIMALS NECROPSIED
 

D-I
 
TABLE D2 (CONCLUDED) 

CONTROL(VEH )

02-F011

 LOR DOSE

 02-FQ1M

 HIGH DOSE 

 02-F015 

BODY CAVITIES 

•PERITODEOM

INFLAMMATION. KOS

 (19)

 1 (5X)

 {5*9)

 1 (2X) 

 (49) 

ALL OTHEH SYSTEMS 

HON E 

SPECIAL BOBPHOLOGY SUHBAR Y 

KO 1ESIOS IEPORTIC

ANIMA L mSSIMG/110 NECROPSY

HECROPSY PZRF/NO BISTO PERFO*MED

 9

 1

 1

 »» 31 

1 

1 

* NUMBE R

* KOHBEB

 OF ANItULS

 OF AIIHALS

 KITH TISS8I

 IECBOPSIED 

 EXAMINE D HICROSCOPICAILY 




DHEW Publication No. (NIH) 78-1380