1978 

National Cancer Institute 

CARCINOGENESIS 

Technical Report Series 

No. 23 

BIOASSAY OF 

PICLORAM 

FOR POSSIBLE CARCINOGENICITY 

CAS No. 1918-02-1 

NCI-CG-TR-23 

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

Public Health Service 

National Institutes of Health 
BIOASSAY OF
 

PICLORAM
 

FOR POSSIBLE CARCINOGENICITY
 

Carcinogen Bioassay and Program Resources Branch
 

Carcinogenesis Program
 

Division of Cancer Cause and Prevention
 

National Cancer Institute
 

National Institutes of Health
 

Bethesda, Maryland 2001A
 

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

Public Health Service
 

National Institutes of Health
 

DHEW Publication No. (NIH) 78-823
 

BIOASSAY OF
 

PICLORAM
 

FOR POSSIBLE CARCINOGENICITY
 

Carcinogenesis Program
 

Division of Cancer Cause and Prevention
 

National Cancer Institute
 

National Institutes of Health
 

CONTRIBUTORS: This report presents the results of the bioassay
 

of picloram for possible carcinogenicity, conducted for the
 

Carcinogen Bioassay and Program Resources Branch, Carcinogenesis
 

Program, Division of Cancer Cause and Prevention, National Cancer
 

Institute (NCI), Bethesda, Maryland. The bioassay was conducted
 

by Gulf South Research Institute, New Iberia, Louisiana,
 initially under direct contract to NCI and currently under a
 

subcontract to Tracer Jitco, Inc., prime contractor for the NCI
 

Carcinogenesis bioassay program.
 

The experimental design was determined by Drs. J. H.
 Weisburger1

'2 and R. R. Bates1*3; the doses were selected by Drs.
 T. E. Shellenberger^»5

, J. H. Weisburger, and R. R. Bates.
 Animal treatment and observation were supervised by Drs. T. E.
 Shellenberger and H. P. Burchfield^, with the technical
 

assistance of Ms. D. H. Monceaux^ and Mr. D. Broussard^.
 Histopathology was performed by Drs. E. Bernal^ and B. Buratto^,
 and the diagnoses included in this report represent the
 

interpretation of these pathologists.
 

Animal pathology tables and survival tables were complied at EG&G
 

Mason Research Institute". Statistical analyses were performed
 

by Dr. J. R. Joiner', using methods selected for the bioassay
 

program by Dr. J. J. Gart°. Chemicals used in this bioassay were
 

analyzed under the direction of Dr. H. P. Burchfield, and the
 

analytical results were reviewed by Dr. S. S. 01in^.
 

This report was prepared at Tracer Jitco under the direction of
 

Dr. Marshall Steinberg', Director of the Bioassay Program; Drs.
 J. F. Robens' and R. W. Fogleraan^, toxicologists; Dr. R. L.
 

ill 
Schueler7

, patholigist; Ms. L. A. Waltz7 and Ms. Y. E. Presley7,
 

technical writers; and Dr. E. W. Gunberg7, technical editor,
 

assisted by Ms. P. J. Graboske7

.
 

The statistical analysis was reviewed by a member or members of
 

the Mathematical Statistics and Applied Mathematics Section of
 

NCI (Dr. John J. Gart, Mr. Jun-mo Nam, Dr. Hugh M. Pettigrew, and
 

Dr. Robert E. Tarone served as reviewers on an alternating
 

basis).
 

The following other scientists at the National Cancer Institute
 

were responsible for evaluating the bioassay experiment,
 

interpreting the results, and reporting the findings:
 

Dr. Kenneth C. Chu
 

Dr. Cipriano Cueto, Jr.
 

Dr. J. Fielding Douglas
 

Dr. Dawn G. Goodman
 

Dr. Richard A. Griesemer
 

Mr. Harry A. Milman
 

Dr. Thomas W. Orme
 

Dr. Robert A. Squire^
 

Dr. Jerrold M. Ward
 

^Carcinogenesis Program, Divison of Cancer Cause and Prevention,
 

National Cancer Institute, National Institutes of Health,
 

Bethesda, Maryland.
 

^Now with the Naylor Dana Institute for Disease Prevention,
 

American Health Foundation, Hammond House Road, Valhalla,
 

New York.
 

-*Now with the Office of the Commissioner, Food and Drug
 

Administration, Rockville, Maryland.
 

^Gulf South Research Institute, Atchafalaya Basin Laboratories,
 

P. 0. Box 1177, New Iberia, Louisiana.
 

->Now with the National Center for Toxicological Research,
 

Jefferson, Arkansas.
 

iv
 
^EG&G Mason Research Institute, 1530 East Jefferson Street,
 

Rockville, Maryland.
 

^Tracor Jitco, Inc., 1776 East Jefferson Street, Rockville,
 

Maryland.
 

^Mathematical Statistics and Applied Mathematics Section,
 Biometry Branch, Field Studies and Statistics, Division of
 

Cancer Cause and Prevention, National Cancer Institute, National
 

Institutes of Health, Bethesda, Maryland.
 

^Now with the Division of Comparative Medicine, Johns Hopkins
 

University, School of Medicine, Traylor Building, Baltimore,
 Maryland.
 

V 

SUMMARY
 

A bioassay of technical-grade piclorara for possible carcinogenicity was conducted by administering the test chemical in feed to
 

Osborne-Mendel rats and B6C3F1 mice.
 

Groups of 50 rats and 50 mice of each sex were administered
 

piclorara in the diet at one of the following doses for 80 weeks.
 

Time-weighted average doses for the rats were 7,437 or 14,875
 

ppm; those for the mice were 2,531 or 5,062 ppm. The rats were
 

then observed for 33 weeks, the mice for 10 weeks. Matched
 

controls consisted of groups of 10 untreated rats or 10 untreated
 

mice of each sex; pooled controls, used for statistical
 

evaluation, consisted of the matched-control groups combined with
 

30 untreated male and 30 untreated female rats or mice from
 

similar bioassays of three other test chemicals. All surviving
 

rats were killed at 113 weeks; all surviving mice were killed at
 

90 weeks. Survival was adequate for meaningful statistical 

analyses of the incidences of tumors in rats and mice of both 

sexes. 

Mean body weights of the high-dose rats were lower than those of
 

the matched controls during the first part of the study; however,
 

beginning at approximately 80 weeks, mean weights of controls
 

were lower than those of treated animals. Body weights of the
 

mice were unaffected by the piclorara.
 

In rats, a relatively high incidence of follicular hyperplasia,
 

C-cell hyperplasia, and C-cell adenoma of the thyroid occurred in
 

both sexes. However, the statistical tests for adenoma did not
 

show sufficent evidence for association of the tumor with
 

picloram administration.
 

An increased incidence of hepatic neoplastic nodules was observed
 

in treated male and female rats as compared with untreated
 

animals. This lesion is considered to be a benign tumor. In
 

male rats the lesion appeared only in three animals of the
 

vii
 
low-dose treatment group and was not significant when compared
 

with the controls; however, the test for positive dose-related
 

trend in females was significant (pooled controls 0/39, low-dose
 

5/50, high-dose 7/49, P = 0.016) and the incidence in the high-


dose group was significant (P = 0.014) when compared with that in
 

the pooled-control group.
 

There was also one hepatocellular carcinoma in a low-dose male
 

rat and one in a high-dose female rat. In both males and
 

females, there was a possibly treatment-related lesion of the
 

liver diagnosed as foci of cellular alteration. The incidences
 

of this latter lesion were, female rats: matched controls 1/10,
 

low-dose 8/50, high-dose 18/49; male rats: matched controls 0/10,
 low-dose 12/49, high-dose 5/49. Thus, there is evidence that
 

picloram affected the livers of rats of both sexes, but more
 

particularly those of the females.
 

No tumors were found in male or female mice or male rats at
 

incidences that could be significantly associated with treatment,
 

and it is concluded that picloram was not carcinogenic for B6C3F1
 

mice or male Osborne-Mendel rats.
 

In female rats, however, the incidence of neoplastic nodules of
 

the liver, benign tumors, was associated with treatment with
 

picloram. It is concluded that under the conditions of the
 

bioassay, the findings are suggestive of the ability of the
 

compound to induce benign tumors in the livers of female
 

Osborne-Mendel rats.
 

viii
 
TABLE OF CONTENTS
 

Page
 

I. Introduction 1
 

II. Materials and Methods 3
 

A. Chemical 3
 

B. Dietary Preparation 3
 

C. Animals 4
 

D. Animal Maintenance 5
 

E. Subchronic Studies 6
 

F. Designs of Chronic Studies 7
 

G. Clinical and Pathologic Examinations..... 10
 

H. Data Recording and Statistical Analyses 11
 

III. Results - Rats 17
 

A. Body Weights and Clinical Signs (Rats) 17
 

B. Survival (Rats) 19
 

C. Pathology (Rats) 19
 

D. Statistical Analyses of Results (Rats) 22
 

IV. Results - Mice 25
 

A. Body Weights and Clinical Signs (Mice) 25
 

B. Survival (Mice) 27
 

C. Pathology (Mice) 27
 

D. Statistical Analyses of Results (Mice) 29
 

V. Discussion 31
 

VI. Bibliography 35
 

APPENDIXES
 

Appendix A Summary of the Incidence of Neoplasms in
 

Rats Fed Picloram in the Diet 37
 

Table Al Summary of the Incidence of Neoplasms in
 

Male Rats Fed Picloram in the Diet 39
 

Table A2 Summary of the Incidence of Neoplasms in
 

Female Rats Fed Picloram in the Diet 43
 

ix
 
Page 

Appendix B Summary of the Incidence of Neoplasms in 

Mice Fed Picloram in the Diet 47 

Table Bl Summary of the Incidence of Neoplasms in 

Male Mice Fed Picloram in the Diet 49 

Table B2 Summary of the Incidence of Neoplasms in 

Female Mice Fed Picloram in the Diet 52 

Appendix C Summary of the Incidence of Nonneoplastic 

Lesions in Rats Fed Picloram in the Diet 55 

Table Cl Summary of the Incidence of Nonneoplastic 

Lesions in Male Rats Fed Picloram in the Diet 57 

Table C2 Summary of the Incidence of Nonneoplastic 

Lesions in Female Rats Fed Picloram in the Diet.... 62 

Appendix D Summary of the Incidence of Nonneoplastic 

Lesions in Mice Fed Picloram in the Diet 65 

Table Dl Summary of the Incidence of Nonneoplastic 

Lesions in Male Mice Fed Picloram in the Diet 67 

Table D2 Summary of the Incidence of Nonneoplastic 

Lesions in Female Mice Fed Picloram in the Diet.... 69 

Appendix E Analyses of the Incidence of Primary Tumors 

in Rats Fed Picloram in the Diet 73 

Table El Analyses of the Incidence of Primary Tumors 

in Male Rats Fed Picloram in the Diet 75 

Table E2 Analyses of the Incidence of Primary Tumors 

in Female Rats Fed Picloram in the Diet 79 

Appendix F Analyses of the Incidence of Primary Tumors 

in Mice Fed Picloram in the Diet 83 

Table Fl Analyses of the Incidence of Primary Tumors 

in Male Mice Fed Picloram in the Diet 85 

Table F2 Analyses of the Incidence of Primary Tumors 

in Female Mice Fed Picloram in the Diet 87 

X 
Page 

Appendix G Analysis of Formulated Diets for 

Concentrations of Picloram 89 

TABLES 

Table 1 Design of Picloram Chronic Feeding 

Studies in Rats 8 

Table 2 Design of Picloram Chronic Feeding 

Studies in Mice 9 

FIGURES 

Figure 1 Growth Curves for Rats Fed Picloram 

in the Diet 18 

Figure 2 Survival Curves for Rats Fed Picloram 

in the Diet 20 

Figure 3 Growth Curves for Mice Fed Picloram 

in the Diet 26 

Figure 4 Survival Curves for Mice Fed Picloram 

in the Diet 28 

xi
 

I. INTRODUCTION
 

Picloram (CAS 1918-02-1; C00237), which is the generic name for
 

4-amino-3,5,6-trichloropicolinic acid, is a systemic herbicide
 

(Neumeyer, 1973; Spencer, 1973) registered by EPA for only
 

nonfood use to control broadleaf weeds and woody plants (EPA
 

Compendium, 1974). The chemical can replace the plant growth
 

hormone indoleacetic acid, and inhibit the synthesis of protein
 

in plants (Bradley, 1974; EPA Compendium, 1974; Neumeyer, 1973).
 

The persistence of picloram in the soil poses environmental
 

problems associated with contamination of the soil and of surface
 

and subsurface water (Edwards, 1976; EPA Compendium, 1974;
 

Hamaker et al., 1963).
 

Picloram was selected for testing because of its herbicidal use,
 

and because its persistence in soil and water suggested a
 

potential for long-term, low-level human exposure.
 

1 

II. MATERIALS AND METHODS
 

A. Chemical
 

Technical-grade picloram was obtained in three batches of Lot No.
 

623816 from Dow Chemical Co., Midland, Michigan, for use in the
 

chronic study. The product was at least 90% pure 4-amino-3,5,6­

trichloropicolinic acid by the manufacturer's assay, and its
 

identity was confirmed by melting point, elemental analyses, and
 

spectral analyses (infrared, ultraviolet, mass, and nuclear
 

magnetic resonance). Thin-layer chroraatography revealed several
 

impurities; no attempt was made to identify or quantitate these
 

impurities.
 

The piclorara was stored at 5°C in the original amber glass
 

containers until used.
 

B.	 Dietary Preparation
 

®
 All diets were formulated using finely ground Wayne Lab Blox
 

(Allied Mills, Inc., Chicago, 111.) to which was added the
 

required amount of picloram for each dietary concentration. A
 

given amount of the test chemical was first hand-mixed with an
 

approximately equal amount of feed. This mixture was then added
 

slowly with mechanical mixing to a larger quantity of feed to
 

give the desired concentration of the chemical. Acetone
 

3 
(Mallinckrodt Inc., St. Louis, Mo.) and corn oil (Louana®,
 

Opelousas Refinery Co., Opelousas, La.) were then added to the
 

feed, each in an amount corresponding to 2% of the final weight
 

of feed. The diets were mixed mechanically for not less than 25
 

minutes to assure homogeneity of the mixture and evaporation of
 

the acetone. Formulated diets were stored at approximately 17°C
 

until used, but no longer than 1 week.
 

As a quality control test on the accuracy of preparation of the
 

diets, the concentration of picloram was determined in different
 

batches of formulated diets during the chronic study. The
 

results are summarized in Appendix G. At each dietary
 

concentration, the mean of the analytical concentrations for the
 

samples tested was within 2.5% of the theoretical concentration,
 

and the coefficient of variation was never more than 6.7%. Thus,
 

the evidence indicates that the formulated diets were prepared
 

accurately.
 

C. Animals
 

Rats and mice of both sexes, obtained through contracts of the
 

Division of Cancer Treatment, National Cancer Institute, were
 

used in these bioassays. The rats were of the Osborne-Mendel
 

strain obtained from Battelle Memorial Institute, Columbus, Ohio,
 

and the mice were B6C3F1 hybrids obtained from Charles River
 

4 
Breeding Laboratories, Inc., Wilmington, Massachusetts. On
 

arrival at the laboratory, all animals were quarantined for an
 

acclimation period (rats for 10 days, mice for 12 days) and were
 

then assigned to control and treated groups.
 

D. Animal Maintenance
 

All animals were housed in temperature- and humidity-controlled
 

rooms. The temperature range was 22-24°C, and the relative
 

humidity was maintained at 40-70%. The air in each room was
 

changed 10-12 times per hour. Fluorescent lighting provided
 

illumination 10 hours per day. Food and water were presented ad
 

libitum.
 

The rats were housed individually in hanging galvanized steel
 

mesh cages, and the mice were housed in plastic cages with filter
 

bonnets, five per cage for females, and two or three per cage for
 

males. Initially, rats were transferred once per week to clean
 

cages; later in the study, cages were changed every 2 weeks.
 

Mice were transferred once per week to clean cages with filter
 

®
 bonnets; bedding used for the mice was Absorb-Ori (Lab Products,
 

Inc., Garfield, N.J.). For rats, absorbent sheets under the
 

cages were changed three times per week. Feeder jars and water
 

bottles were changed and sterilized three times per week.
 

Cages for control and treated mice were placed on separate racks
 

5 
in the same room. Animal racks for both species were rotated
 

laterally once per week; at the same time, each cage was changed
 

to a different position in the row within the same column. Rats
 

receiving picloram, along with their matched controls, were
 

housed in a room by themselves. Mice receiving picloram were
 

maintained in a room housing mice administered chlorothalonil
 

(CAS 1897-45-6), chloramben (CAS 133-90-4), or endrin (CAS
 

72-20-8), together with their respective matched controls.
 

E. Subchronic Studies
 

Subchronic feeding studies were conducted to estimate the maximum
 

tolerated doses of picloram, on the basis of which low and high
 

concentrations (hereinafter referred to as "low doses" and "high
 

doses") were determined for administration in the bioassay. In
 

these subchronic studies, picloram was added to the animal feed
 

in twofold increasing concentrations, ranging from 1,250 to
 

20,000 ppm for rats and 1,250 to 30,000 ppm for mice. The
 

treated and matched-control groups each consisted of five male
 

and five female animals. Picloram was provided in feed to the
 

treated groups for 6 weeks, followed by a 2-week period of
 

observation.
 

For the first 3 weeks of the study, the weights of the male rats
 

receiving 20,000 ppm picloram were slightly lower than those of
 

6 
the matched controls. However, the mean body weights of the
 

female rats receiving 10,000 or 20,000 ppm were similar to those
 

of the matched controls, except during week 1. No deaths
 

occurred in either sex at doses of 10,000 or 20,000 ppm. The low
 

and high doses for both male and female rats were set at 10,000
 

and 20,000 ppm for the chronic studies.
 

Weight gains of male and female mice receiving 5,000 and 10,000
 

ppm picloram were comparable to those of the matched controls.
 

No deaths occurred in either sex at doses of 5,000 or 10,000 ppm.
 

Of the animals receiving 20,000 ppm, 4/5 males and 3/5 females
 

died. The low and high doses for both male and female mice for
 

the chronic studies were set at 5,000 and 10,000 ppm.
 

F. Designs of Chronic Studies
 

The designs of the chronic studies are shown in tables 1 and 2.
 

Since the numbers of animals in the matched-control groups were
 

small, pooled-control groups also were used for statistical
 

comparisons. Matched controls from the current studies on
 

picloram were combined with matched controls from studies on
 

phosphamidon (CAS 13171-21-6), tetrachlorvinphos (CAS 961-11-5),
 

and chloramben (CAS 133-90-4). The pooled controls for statistical tests using rats consisted of 40 males and 40 females; using
 

mice, 40 males and 40 females. The studies on chemicals other
 

7 
Table 1. Design of Picloram Chronic Feeding Studies in Rats
 

Sex and Initial Picloram Time on Study Time-Weighted 

Treatment 

Grou£ 

No. of 

Animals3 

in Diet 

Cpj>m) 

Treated 

(weeks )b 

Untreated 

(weeks)c Average Dose^ 

(ppm) 

Male 

Matched-Control 10 0 113 

Low-Dose 50 10,000 39 7,437 

5,000 41 

0 33 

High-Dose 50 20,000 39 14,875 

10,000 41 

0 33 

Female 

Matched-Control 10 0 113 

Low-Dose 50 10,000 39 7,437 

5,000 41 

0 33 

High-Dose 50 20,000 39 14,875 

10,000 41 

0 33 

a

All animals were 35 days of age when placed on study.
 

''Doses of picloram were lowered at 39 weeks on study, since it was
 

believed that excessive mortality would occur before termination
 

of the study, based on the pattern of mortality, weight changes,
 

and the general condition of rats used in similar studies on other
 

chemicals at Gulf South Research Institute.
 

c

When test diets were discontinued, treated and control rats were
 

fed control diets without corn oil for 4 weeks, then control diets
 

(2% corn oil added) for an additional 29 weeks.
 

d

Time-weighted average dose •

£

.(dose in ppm x no. of weeks at that dose)
 

£ (no. of weeks receiving each dose)
 

8 
Table 2. Design of Picloram Chronic Feeding Studies in Mice
 

Sex and 

Treatment 

Group 

Initial 

No. of 

Animals3 

Picloram 

in Diet 

(ppm) 

Time on Study 

Treated 

(weeks )b 

Untreated 

(weeks)c 

Time-Weighted 

Average Dosec 

(ppm) 

Male 

Matched-Control 10 0 90 

Low-Dose 50 5,000 1 2,531 

2,500 79 

0 10 

High-Dose 50 10,000 1 5,062 

5,000 79 

0 10 

Female 

Matched-Control 10 0 90 

Low-Dose 50 5,000 1 2,531 

2,500 79 

0 10 

High-Dose 50 10,000 1 5,062 

5,000 79 

0 10 

a

All animals were 35 days of age when placed on study.
 

^Doses of picloram were lowered at 1 week on study, since it was
 

believed that excessive mortality would occur before termination
 

of the study, based on the pattern of mortality, weight changes,
 

and the general condition of mice used in similar studies on other
 

chemicals at Gulf South Research Institute.
 

c

When test diets were discontinued, treated and control mice were
 

fed control diets (2% corn oil added).
 

d

Time-weighted average dose -^ (dose in ppm x no. of weeks at that dose)
 

E (no. of weeks receiving each dose)
 

9 
than piclorara were also conducted at Gulf South Research
 

Institute and overlapped the picloram study by at least 1 year.
 

The matched-control groups for the different test chemicals were
 

of the same strain and from the same supplier, and they were
 

examined by the same pathologists.
 

G. Clinical and Pathologic Examinations
 

All animals were observed twice daily for signs of toxicity,
 

weighed at regular intervals, and palpated for masses at each
 

weighing. Animals that were moribund at the time of clinical
 

examination were killed and necropsied.
 

The pathologic evaluation consisted of gross and microscopic
 

examination of major tissues, major organs, and all gross lesions
 

from killed animals and from animals found dead. The following
 

tissues were examined microscopically: skin, lungs and bronchi,
 

trachea, bone and bone marrow, spleen, lymph nodes, heart,
 

salivary gland, liver, gallbladder (mice), pancreas, stomach,
 

small intestine, large intestine, kidney, urinary bladder,
 

pituitary, adrenal, thyroid, parathyroid, mammary gland, prostate
 

or uterus, testis or ovary, and brain. Occasionally, additional
 

tissues were also examined microscopically. The different
 

tissues were preserved in 10% buffered formalin, embedded in
 

paraffin, sectioned, and stained with hematoxylin and eosin.
 

10
 
Special staining techniques were utilized when indicated for more
 

definitive diagnosis.
 

A few tissues from some animals were not examined, particularly
 

from those animals that died early. Also, some animals were
 

missing, cannibalized, or judged to be in such an advanced state
 

of autolysis as to preclude histopathologic evaluation. Thus,
 

the number of animals from which particular organs or tissues
 

were examined microscopically varies, and does not necessarily
 

represent the number of animals that were placed on study 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
 

11
 
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 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) for testing two groups for equality and Tarone's (1975)
 

extensions of Cox's methods for testing for 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 is 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
 

12
 
appeared at multiple sites (e.g., lymphoraas), 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) was used to compare the tumor incidence of
 

a control group with 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) 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), was also used. Under the
 

assumption of a linear trend, this test determines 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 is a positive dose relation13
 
ship. 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 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
 

14 4
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 treated group compared to its control was calculated
 

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

relative risk is defined as Pt/Pc where pt is the true binomial
 

probability of the incidence of a specific type of tumor in a
 

treated group of animals and pc is the true probability of the
 

spontaneous incidence of the 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 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% 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
 

15 5
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 greater 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.
 

16
 
III. RESULTS - RATS
 

A. Body Weights and Clinical Signs (Rats)
 

The mean body weights of the rats fed picloram were slightly
 

lower than those of the matched controls until week 16 (figure
 

1). For the remainder of the study, however, the weights of the
 

matched controls, particularly the males, were increasingly lower
 

than those of the treated groups.
 

During the first 6 months of the study, the treated rats were
 

generally comparable to the controls in appearance and behavior.
 

During the second 6 months, clinical signs including diarrhea,
 

hematuria, and rough hair coats were observed at a moderate
 

incidence. At week 35 a few animals in each group, treated and
 

matched-control, had an enlarged and protruding eyeball with a
 

developing opacity of the corneal surface, and in some cases a
 

definite thickening of the palpebral conjunctival membranes; this
 

condition was diagnosed as viral conjunctivitis and left affected
 

animals blind. This disease was considered to be incidental in
 

the colony and was not related to treatment with picloram.
 

During the second year of the study, clinical signs were observed
 

with an increased frequency in the treated rats. These signs
 

17
 
D MATCHED CONTROL 

O LOW DOSE 

A HIGH DOSE 

Figure 1. Growth Curves For Rats Fed Picloram In The Diet 

18 
included pale mucous membranes, dermatitis, alopecia, tachypnea,
 

discolored (dark.) urine, diarrhea, and vaginal bleeding.
 

B. Survival (Rats)
 

The Kaplan and Meier curves estimating the probabilities of
 

survival for male and female rats receiving picloram at the doses
 

of this experiment, together with those of the matched controls,
 

are shown in figure 2. In both sexes, the Tarone test results
 

for positive dose-related trend in mortality over the period are
 

not significant at the 0.05 level. In male rats, 49% of the
 

high-dose group, 68% of the low-dose group, and 50% of the
 

matched-control group lived to the end of the study. Deaths in
 

the high-dose group which occurred prior to termination of the
 

study were not tumor associated. In females, survivals among
 

the three groups are comparable; 69% of the high-dose group, 66%
 

of the low-dose group, and 70% of the controls lived to the end
 

of the study. Survival was adequate for meaningful statistical
 

analyses of the incidences of tumors in these groups.
 

C. Pathology (Rats)
 

Histopathologic findings on neoplasms in rats are summarized in
 

Appendix A, tables Al and A2; findings on nonneoplastic lesions
 

are summarized in Appendix C, tables Cl and C2.
 

19
 
Figure 2. Survival Curves For Rats Fed Picloram In The Diet 

20 
Similar lesions occurred among animals of the matched-control and
 

treated groups. For the most part, these lesions are commonly
 

encountered in aging rats of the Osborne-Mendel strain.
 

Furthermore, the incidence in which they occurred in treated rats
 

was similar to that in which they were observed to occur
 

spontaneously in similar studies. However, there was a
 

relatively high incidence of follicular and C-cell hyperplasia
 

and/or neoplasia of the thyroid gland, neoplastic nodules of the
 

liver, and cellular alteration of the liver exclusively or almost
 

exclusively in picloram-treated rats. The neoplastic nodules
 

were composed predominantly of eosinophilic hepatocytes and
 

lesser numbers of clear hepatocytes. Foci of cellular alteration
 

composed of eosinophilic and/or clear hepatocytes were seen in
 

the livers of several treated rats. The significance of these
 

changes in both the thyroid and the liver is difficult to assess
 

because of the disproportionately small number of matched-control
 

animals.
 

Although neoplastic nodules and foci of cellular alteration were
 

observed in the liver of only treated male and female rats and
 

may have been treatment related, in the judgment of the
 

pathologist, there was no conclusive evidence of carcinogenicity
 

induced by picloram in Osborne-Mendel rats at the doses administered and for the period of time rats were fed in this study.
 

21
 
D

• Statistical Analyses of Results (Rats)
 

Tables El and E2 In Appendix E contain the statistical analyses
 

of the incidences of those specific primary tumors that were
 

observed in at least 5% of one or more treated groups of either
 

sex.
 

In the analyses of the incidence of neoplastic nodule of the
 

liver in female rats, the Cochran-Armitage test result for
 

positive dose-related trend in proportions is significant (P •
 

0.016) using the pooled controls, and the Fisher exact test shows
 

a significantly higher incidence of this tumor in the high-dose
 

group (P - 0.014) when compared with the pooled controls. The
 

statistical conclusion is that the occurrence of neoplastic
 

nodule of the liver in female rats is associated with picloram at
 

the doses administered in this experiment. The statistical test
 

results of the incidence of this tumor in male rats are not
 

significant at the 0.05 level.
 

In female rats, although the Cochran-Armitage test result for
 

positive dose-related trend in proportions for C-cell adenoma of
 

the thyroid is significant (P TM 0.029) using the pooled controls,
 

the Fisher exact test for comparisons of the incidences in the
 

treated groups with those in the control groups do not confirm
 

22
 
this result. Statistical tests of the incidence of this tumor in
 

male rats are not significant at the 0.05 level.
 

There are no other tumors for which the statistical test results
 

of the incidences are significant in the positive direction. In
 

all of the confidence intervals shown in the tables for the
 

incidences of tumors, other than those in the liver, the value of
 

one or less than one is included, indicating the absence of
 

significant positive results. It should also be noted that these
 

intervals, except the incidence of chromophobe adenoma of the
 

pituitary in low-dose male rats, have upper limits greater than
 

one, indicating the theoretical possibility of the induction of
 

tumors by picloram, which could not be detected under the
 

conditions of this test. Elimination of those animals dying
 

before week 52 on study does not affect the conclusions of this
 

analysis.
 

23
 

IV. RESULTS - MICE
 

A. Body Weights and Clinical Signs (Mice)
 

The mean body weights of the treated male and female mice were
 

essentially unaffected by the picloram over the period of the
 

bioassay (figure 3).
 

During the first 16 weeks of the study, the treated mice were
 

generally comparable to the controls in appearance and behavior.
 

At week 17, one low-dose female and five high-dose females had
 

generalized body tremors. During the remainder of the first
 

year, the general condition of both treated and control mice was
 

good. A few individual animals lost weight, and had alopecia and
 

fight wounds.
 

During the second year of the study, clinical signs were noted
 

with increasing frequency among the treated mice. At week 52, a
 

majority of treated males appeared to be slightly hyperactive.
 

Rough hair coats were observed in low-dose males beginning at
 

week 57 and in high-dose males beginning at week 68 and
 

continuing to termination of the study. Other clinical signs
 

included abdominal distention, predominantly among the low-dose
 

males and females.
 

25
 
Figure 3. Growth Curves For Mice Fed Picloram In The Diet 

26 
B• Survival (Mice)
 

The Kaplan and Meier curves estimating the probabilities of
 

survival for male and female mice receiving picloram at the doses
 

of this experiment, together with those of the matched controls,
 

are shown in figure 4. In neither sex was the Tarone test result
 

significant at the 0.05 level for positive dose-related trend in
 

mortality over the period. With over 80% of both male and female
 

groups living to termination of the study, survival was adequate
 

for meaningful statistical analyses of the incidences of
 

late-developing tumors.
 

c

• Pathology (Mice)
 

Histopathologic findings on neoplasms in mice are summarized in
 

Appendix B, tables Bl and B2; findings on nonneoplastic lesions
 

are summarized in Appendix D, tables Dl and D2.
 

Neoplastic and nonneoplastic lesions were found in mice of the
 

treated and matched-control groups. The lesions occurred with a
 

wide variation, random distribution, and either in insignificant
 

numbers or with approximately equal frequency among mice of the
 

treated and control groups.
 

In the judgment of the pathologist, there was no conclusive
 

evidence of carcinogenicity induced by picloram in the B6C3F1
 

27
 
Figure 4. Survival Curves For Mice Fed Picloram In The Diet 

28 
hybrid mouse at the doses administered and for the period of time
 

mice were fed in this study.
 

D. Statistical Analyses of Results (Mice)
 

Tables Fl and F2 in Appendix F contain the statistical analyses
 

of the incidences of those specific primary tumors that were
 

observed in at least 5% of one or more treated groups of either
 

sex.
 

In neither sex were the results of the Cochran-Armit^ge test for
 

positive dose-related trend in proportions or the Fisher exact
 

test for comparisons of incidences between the treated groups and
 

the control groups significant at the 0.05 level. In all of the
 

95% confidence intervals shown in the tables for the incidence of
 

tumors, the lower limit has a value of less than one, indicating
 

the absence of positive significant results. It should also be
 

noted that these intervals have upper limits greater than one,
 

indicating the theoretical possibility of the induction of tumors
 

by picloram, which could not be detected under the conditions of
 

this test.
 

29
 

V. DISCUSSION
 

In this bioassay, picloram did not consistently affect the body
 

weights of the treated animals. Mean body weights of high-dose
 

rats were lower than those of the matched controls early in the
 

study, but beginning at approximately 80 weeks, mean weights of
 

controls were lower than those of the treated animals.
 

Body weights of mice were unaffected by picloram. No consistent
 

clinical signs attributable to treatment were reported during the
 

first 6 months of the study, except for isolated incidences of
 

tremors and hyperactivity in mice. Later, particularly during
 

the second year, rough hair coats, diarrhea, pale mucous
 

membranes, alopecia, and abdominal distention occurred in both
 

treated rats and mice to a greater degree than in the controls.
 

Survival was adequate for meaningful statistical analyses of the
 

incidences of tumors in groups of rats and mice of both sexes.
 

In rats, a relatively high incidence of follicular hyperplasia,
 

C-cell hyperplasia, and C-cell adenoma of the thyroid occurred in
 

both sexes. However, the statistical tests for adenoma did not
 

show sufficient evidence for association of the tumor with
 

picloram administration.
 

An increased incidence of hepatic neoplastic nodules was observed
 

31
 
in treated male and female rats as compared with untreated
 

animals. This lesion is considered to be a benign tumor. In
 

male rats the lesion appeared only in three animals of the
 

low-dose treatment group and was not significant when compared
 

with the controls; however, the test for positive dose-related
 

trend in females was significant (pooled controls 0/39, low-dose
 

5/50, high-dose 7/49, P = 0.016), and the incidence in the
 

high-dose group was significant (P * 0.014) when compared with
 

that in the pooled-control group.
 

There was also one hepatocellular carcinoma in a low-dose male
 

rat and one in a high-dose female rat. In both males and
 

females, there was a possibly treatment-related lesion of the
 

liver diagnosed as foci of cellular alteration. These latter
 

lesions are frequently associated with the induction of neoplastic nodules and hepatocellular carcinomas in rats (Squire and
 

Levitt, 1975). The incidences of the foci were, female rats:
 

matched controls 1/10, low-dose 8/50, high-dose 18/49; male rats:
 

matched controls 0/10, low-dose 12/49, high-dose 5/49. Thus,
 

there is evidence that picloram affected the livers of rats of
 

both sexes, but more particularly those of the females.
 

In mice, no tumors occurred in proportions that could be shown to
 

be related to the administration of picloram, either by tests for
 

32
 
dose-related trend or by direct comparisons of the incidences in
 

treated and control groups.
 

In previous studies of the toxicity of piclorara, Lynn (1965)
 

reported LD5QS of 2,000 to 4,000 rag/kg in the female mouse and
 

over 8,000 mg/kg in the female rat. McCollister and Leng (1969)
 

reported no adverse effects or tumors in albino rats and Beagle
 

dogs at intakes up to 150 mg/kg/day for 2 years. Intakes of 150
 

rag/kg/day are lower than the doses used for rats in the present
 

bioassay.
 

No tumors were found in male or female mice or male rats at
 

incidences that could be significantly associated with treatment,
 

and it is concluded that picloram was not carcinogenic for B6C3F1
 

mice or male Osborne-Mendel rats.
 

In female rats, however, the incidence of neoplastic nodules of
 

the liver, benign tumors, was associated with treatment with
 

picloram. It is concluded that under the conditions of the
 

bioassay, the findings are suggestive of the ability of the
 

compound to induce benign tumors in the livers of female
 

Osborne-Mendel rats.
 

33
 

VI. BIBLIOGRAPHY
 

Armitage P. , Statistical Methods in Medical Research, John Wiley
 

& Sons, Inc., New York, 1971, pp. 362-365.
 

Berenblum, I., ed., Carcinogenic!ty Testing; A Report of the
 

Panel on Carcinogenicity of the Cancer Research Commission
 

of the UICC, Vol.2, International Union Against Cancer,
 

Geneva, 1969.
 

Bradley, R. T., Shoemaker, J. P. and Hoffman, R. V., Jr., Treatment of Experimental Mammary Adenocarcinoma with Herbicides.
 

Cancer Chemother. Rep. 58;745-748. 1974.
 

Cox, D. R., Regression models and life tables. J. R. Statist.
 

Soc. B 34:187-220. 1972.
 

Cox, D. R. , Analysis of Binary Data, Methuen & Co., Ltd.,
 

London, 1970, pp. 48-52.
 

Edwards, C. A., Persistent Pesticides in the Environment. 2nd
 

edition, CRC Press, Cleveland, Ohio, 1976.
 

Environmental Protection Agency, EPA Compendium of Registered
 

Pesticides. U. S. Government Printing Office, Washington,
 

D. C., I-P-16.1 - I-P-16.3, 1974.
 

Gart, J. J., The comparison of proportions: a review of
 

significance tests, confidence limits and adjustments for
 

stratification. Rev. Int. Stat. Inst. 39:148-169. 1971.
 

Hamaker, J. W. , Johnston, H. , Martin, R. T. , and Redemann, C. T. ,
 

A picolinic acid derivative: a plant growth regulator.
 

Science 141:363. 1963.
 

Kaplan, E. L. and Meier, P. , Nonparametric estimation from
 

incomplete observations. J. Am. Statist. Assoc. 53:457-481,
 

1958.
 

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

Peters, J. A., Carcinogenesis bioassay data system. Comp.
 

and Biomed. Res. 7:230-248. 1974.
 

Lynn, G. E., A review of toxicological information on Tordon
 

herbicides. Down to Earth 20 (4):6-8, 1965.
 

35
 
McCollister, D. D. and Leng, M. L. , A review of agricultural
 

chemical progress. Down to Earth 25 (2):5-10, 1969.
 

Miller, R. G., Jr., Simultaneous Statistical Inference,
 

McGraw-Hill Book Co., New York, 1966, pp. 6-10.
 

Neumeyer, J., Herbicides. In: The Encyclopedia of Chemistry,
 

3rd edition, Hampel, C. A. and Hawley, G. G., eds., Van
 

Nostrand Reinhold, New York, 1973, pp. 526-529.
 

Saffiotti, U., Montesano, R. , Sellakumar, A. R., Cefis, F., and
 

Kaufman, D. G. , Respiratory tract carcinogenesis in
 

hamsters induced by different numbers of administrations of
 

benzo(a) pyrene and ferric oxide. Cancer Res 3_2: 1073-1081,
 

1972.
 

Spencer, E. Y. , Guide to Chemicals Used in Crop Protection,
 

Research Institute, University of Western Ontario, London,
 

Ontario, 1973, p. 414.
 

Squire, R. A. and Levitt, M. H. , Report of a workshop on
 

classification of specific hepatocellular lesions in rats.
 

Cancer Res. 35;3214-3223. 1975.
 

Tarone, R. E., Tests for trend in life table analysis.
 

Biometrika 62 £3).: 679-682, 1975.
 

36
 
APPENDIX A
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

RATS FED PICLORAM IN THE DIET
 

37
 

TABLE A1.

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN MALE RATS 

FEDPICLORAMINTHE DIET 

CONTROL L OW DOSE HIGH DOSE 

ANIMAL S

ANIMAL S

ANIMAL S

 INITIALLY IN STUDY 

 NECROPSIED 

 EXAMINE D HISTOPATHOLOGICA LLY 

10 

10 

10 

50 

50 

50 

50 

50 

U9 

INTEGUMENTAR Y SYSTEM 

*SKI N 

BASAL-CELL CARCINOMA 

(10) (50) 

1 (2X) 

(50) 

*SUBCOT TISSUE 

FIBBCM A 

FIBROUS HISTIOCYTOHA 

(10) (50) (50) 

1

1

 (2%) 

 (2*) 

RESPIRATOR Y SYSTEM 

tLON G 

UNCIFFERENTIATE D CARCINOM A META S 

PHEOCHROHOCYTOHA, METASTATIC 

(10) (it 9) (50) 

1

1

 (2*) 

 (2%) 

HEMATOPOIETIC SYSTE M 

*MULTIPLE ORGAN S 

MALIG . LYMPHOMA , UNDIF F ER- TYPE 

LYMPHOCYTI C LEUKEMI A 

(10) (50) 

1 (2%) 

(50) 

1 (2*) 

JSPLEE N 

UNCIFFERENTIATE D CARCINOM A

HEMANGIOM A 

 META S 

(10) (50) 

3 (61) 

(50) 

1

1

 (2*) 

(2%) 

CIRCULATOR Y SYSTE M 

#HEART 

FIBRCM A 

(10) 

.

(49) 

__1 J2X1 _. 

(50) 

t NUMBE R

* NUMBE R

 O F ANIMAL S

 OF ANIMAL S

 WITH TISSUE

 NECtiOPSIED 

 EXAMINE D MICROSCOPICALL Y 

39 
TABLE A1. MALE RATS: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIG H DOSE 

DIGESTIVE SYSTE M 

#LIVEP 

UNDIFFERENT I ATE D CARCINOM A

HEOPLASTIC NODUL E 

HEPATOCELLOLA R CARCINOM A 

FIBROSARCOM A 

 NETA S 

(10 ) ( U 9) 

3 (6%) 

1 (2% ) 

1 (2%) 

(49) 

1 (2*) 

*BILE DOCT 

BILI DUCT ADENOM A 

(10) (50) (50) 

1 (2%) 

#PANCREA S 

^DIFFERENTIATE D CARCINOM A 

(10) (U9 ) (49) 

1 (2%) 

tSTCMACH 

UNDIFFERENTIATE D CARCINOM A META S 

PAPILLOMA , NO S 

(10) (50) (46) 

1 (2% ) 

1 (2% ) 

URINAR Y SYSTEM 

#KIDNE Y 

TUBULAR-CEL L ACENDM A 

(10 ) (50) (50) 

1 (2%) 

ENDOCRIN E SYSTE M 

•PITUITAR Y 

CAPCINCM A ,NOS 

CHEOMOPHOEE ADENOM A 

(9) 

2 (22*) 

(46) 

2 (4% ) 

2 (US) 

(45) 

9 (20*) 

tADRENA L 

CORTICAL ADENCM A 

PHEOCHROMOCYTOM A , MALIGNAN T 

(10 ) (U9 ) 

2 (4%) 

(49 ) 

1 (2% ) 

tTHYSOI D 

C-CELL ADENOM A 

C-CSLL CARCINOM A 

(9) (47 ) 

6 ( 1 3« ) 

(49 ) 

1

1

 (2*) 

 (2*) 

REPRODUCTIV E SYSTE M 

*MAMMAR Y GLAN D 

FIBROM A 

(10) 

1 (10% ) 

(50) 

1 (2S) 

(50) 

1 (2% ) 

NERVOU S SYSTE M 

I BRAI N 

KENINGIOM A 

(10 ) 

.__

(49 ) 

.1 J2%1__ . 

(50) 

# NUMBE R O F ANIMAL S WIT H TISSU E EXAMINE D MICROSCOPICALL Y 

* NUflBE B OF ANIMAL S N FC ROP <=:T ?n 

40 
TABLE A1. MALE RATS: NEOPLASMS (CONTINUED) 

CONTROL L OW DOSE HIGH DOSE 

SPECIA L SENS E ORGAN S 

NON E 

MUSCULOSKELETA L SYSTE M 

NON E 

BODY CAVITIES 

*ABDCMINA L CAVIT Y 

UNDIFFERENTIATE D CARCINOM A BETA S 

*HESENTER Y 

UNDIFFEEENTIATE D CARCINOM A META S 

(10 ) 

(10) 

(50) 

(50) 

(50) 

1

(50) 

1

 (2X ) 

 (2%) 

A LL CTHER SYSTEM S 

*MULTIPL E ORGAN S 

FIBROU S HISTIOCYTOMA, MALIGNAN T 

(10) (50) 

1 (2*) 

(50) 

1 (2*) 

DIAPHRAG M 

IJNCIFFERENTIATE D CARCINOM A META S 1 

ANIMA L DISPOSITION SUMMAR Y 

ANIMAL S INITIALLY IN STDDY 

NATURA L DEATHS 

MORIBUN D SACRIFICE 

SCHEDULE D SACRIFICE 

ACCIDENTALLY KILLE D 

TERMINA L SACRIFICE 

ANIMA L MISSING 

10 

5 

5 

50 

6 

11 

33 

5C 

10 

16 

24 

9 INCLUDE S AUTOLYZE D ANIMALS 

* NUMBE R

* NUMBE R

 OF ANIMAL S WIT H TISSUE

 OF ANIMAL S NECROPSIED 

 EXAMINE D MICROSCOPICALLY 

41 
TABLE A1. MALE RATS: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

TUMO R SUMMAR Y 

TOTA L ANIMAL S WIT H PRIMAR Y TUMORS * 3 23 18 

TOTAL PRIMAR Y TUMOR S 3 26 22 

TOTAL ANIMAL S WIT H BENIG N TUMOR S 3 1 K 13

 

TCTA L BENIG N TUMOR S 3 15 17

 

T O T A L ANIMAL S W I T H MALIGNAN MALIGNAN T TUMORS 8 5 

TOTAL MALIGNAN MALIGNAN T TUMOR TUMORSS 8 5

 

T O T A L ANIMAL S W I T H SECONDAR SECONDAR Y TUMORS TUM* 22 

T O T A L SECONDAR SECONDAR Y TUMOR S 8 

T O T A L ANIMAL S W I T H T U M O RT U M O R S UNCERTAIN UNCERTAIN-­

BENIG N O R MALIGNAN MALIGNANTT 3

 

T O T A L UNCERTAI UNCERTAI N TUMOR S 3 

T C T A I ANIMAL S W I T H T U M O FT U M O F S UNCERTAIN UNCERTAIN­-

PRIMAR Y OR METASTATI METASTATIC 

T O T A L UNCERTAI UNCERTAI N T U M O RT U M O R S 

* PRIMAR Y TUMORS : AL L TUMOR S EXCEPT SECONDAR Y TUMORS 

t SECONDAP Y TUMORS : METASTATIC TUMOR S O R TUMOR S INVASIV E INTO A N ADJACEN T ORGA N 

42 
TABLE A2.

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE RATS 

FEDPICLORAMINTHE DIET 

CONTRO L L OB DOSE HIGH DOSE 

ANIMAL S INITIALL Y I N STUDY 10 50 50 

ANIMAL S NECROPSIED 10 50 50 

ANIMAL S EXAMINE D HISTOPATHOLOGICALL Y 10 50 49 

INTEGUMENTAR Y SYSTE M 

*SUBCU T TISSUE 

SAFCCMA , NOS 

FIBROU S HISTIOCYTOMA 

(10) 

1 (10S) 

(50) (50) 

1 (2%) 

3ESPIHATCR Y SYSTEM 

#LUN G (10) (50) (49) 

LIPCSARCCMA , METASTATIC 1 (2«) 

OSTEOSARCOMA , METASTATIC 1 (2*) 

HEMATOPOIETI C SYSTE M 

*MULTIPLE ORGAN S (10) (50) (50) 

LYMPHOCYTIC LEUKEMI A 1 (10X) 1 (2X) 

CIRCULATOR Y SYSTEM 

NON E 

DIGESTIVE SYSTE M 

tLIVE R (10) (50) (49) 

NEOPLASTIC NODULE 5 (10X) 7 (14X) 

HEPATOCELLULA R CARCINOM A 1 <2X ) 

URINAR Y SYSTE M 

tKIDNE Y (10) (U8 ) (U8) 

LIPCSARCOMA 1 (2%) 

t HAMARTOM A 1_12«L 1 12%L 

* NUMBER OF ANIMAL S WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMAL S NECROPSIED 

t This is considered to be a benign form of the malignant mixed tumor
 

of the kidney and consists of lipocytes, tubular structures, and
 

fibroblasts in varying proportions.
 

43
 
TABLE A2. FEMALE RATS: NEOPLASMS (CONTINUED) 

CONTPO L L OW DOSE 

ENDOCRIN E SYSTE M 

IPITUITAR Y (9) (48 ) 

CARCINOMA , NO S 1 (11X ) 

ADENOMA , NO S 1 (2% ) 

CHEOMOPHOBE ADENOM A 7 (15% ) 

tADRENA L (8) (50) 

CORTICA L ADENOM A 2 («%) 

PHEOCHROMOCYTOMA 

OSTEOSARCOMA , KETASTATI C 1 (2%) 

ITHYROI D (9) (46 ) 

C-CEL L A DENOM A 3 (7% ) 

• PANCREATI C ISLETS (10 ) (47 ) 

ISLET-CEL L ADENOM A 1 (2X) 

REPRODUCTIV E SYoTF H 

*KAMMAP Y GLAN D (10} (50) 

INFILTRATIN G DUCT CARCINOM A 1 (2X) 

FIBROM A 1 (10% ) 1 (2X ) 

FIBEOADENOMA 6 (12X) 

*UTERU S (10) (48) 

SQUAMOU S CELL CARCINOM A 1 (2%) 

GRANULOSA-CEL L CARCINOMA , METAST 1 (2%) 

ENDOMETRIA L STROMA L POLYP 1 (10«) 8 (17% ) 

ENDOBETRIA L STROMA L SARCOM A 

tUTEROS/ENDOMETRIO M (10) (48) 

ADOCCARCINOMA , NOS 1 (2%) 

# OVAR Y (10) (47) 

GRANULOSA-CEL L CARCINOM A 1 (2X) 

NERVOU S SYSTE M 

*BRAI N (10) (50) 

GRANULAR-CEL L TUMOR, BENIG N 

GRANULAR-CEL L TUMOR , MALIGNAN T 1 (2X) 

OLIGeDENDROGLiafiA 1.12SL 

* NUMBE R OF ANIMAL S WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBER OF ANIMAL S NECROPSIED 

HIG H DOSE 

(46) 

7 (15% ) 

(48) 

4 (8%) 

1 (2%) 

(46) 

7 (15%) 

(49) 

1 (2%) 

(50) 

1 (2% ) 

2 (4%) 

4 (8X) 

(45) 

4 (9X) 

1 (2%) 

(45) 

(48) 

(49) 

1 (2X) 

1 12%1. 

44 
TABLE A2. FEMALE RATS: NEOPLASMS (CONTINUED)

 

CONTROL 

SPECIAL SENSE ORGAN S 

NON E 

NUSCULCSKELETA L SYSTEM 

*SHOULDEP JOINT 

CSTECSARCOMA 

(10) 

BODY CAVITIES 

*MESENTEE Y 

GHANOLOSA-CELL CARCINOMA , METAS T 

(10) 

A LL OTHER SYSTEM S 

*MULTIPLE ORGAN S 

"IBRCQS HISTIOCYTOMA, MALIGNAN T 

(10) 

ANIMA L DISPOSITION SDMMAR Y 

ANIMAL S INITIALLY I N STUDY 

NATURA L DEATHS 

MOP.IBON D SACRIFICE 

SCHEDULE D SACRIFICE 

ACCIDENTALL Y KILLE D 

TERMINA L SACRIFICE 

ANIKA L MISSING 

10 

1 

2 

7 

9 INCLUDE S AUTOLYZE D ANIMALS 

LOH DOSE HIGH DOSE 

(50) 

1 (2%) 

(50) 

(50) 

1 (2«) 

(50) 

(50) 

1 (2%) 

(50) 

50 

2 

15 

33 

50 

<l 

11 

1 

3« 

t NUMBE P OP ANIMAL S WIT H TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMAL S NECROPSIED 

45 
TABLE A2. FEMALE RATS: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE
 

TUMOB SUMMARY
 

TOTAL ANIMALS WITH PBIMARY TUMORS* 5 32 30
 

TOTAL FEIMARY TOMOES 5 H3 U6
 

TOTAL ANIMALS WITH BENIGN TUMORS 2 25 23
 

TOTAL BENIGN TUMOBS 2 30 33
 

TOTAL ANIMALS WITH MALIGNANT TUMOBS 3 6 6
 

TOTAL MALIGNANT TUMORS 3 8 6
 

TOTAL ANIMALS WITH SECONDARY TUMORS*: 2 1
 

TOTAL SECONDARY TUMORS U 1
 

TOTAL ANIMALS WITH TUMORS UNCERTAINBENIGN OR MALIGNANT 5 7
 

TOTAL UNCERTAIN TUMORS 5 7
 

TCTA
OLL ANIMALS WITH TUMORS UNCERTAIN UNCERTAIN-­

P R I M A RP R I M A RY CR METASTATI METASTATIC
 

TOTAL UNCERTAI UNCERTAIN TUMORS
 

* PRIMARY TUMORS: ALL TUMORS EXCEPT SECONDARY TUMORS
 

f SECONDARY TUMORS: METASTATIC TUMORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 

46
 
APPENDIX B
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

MICE FED PICLORAM IN THE DIET
 

47
 

TABLE B1.

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN MALE MICE 

FEDPICLORAMINTHE DIET 

CONTROL LOW DOSE HIGH DOSE 

ANIMAL S

ANIMAL S

ANIMAL S

 INITIALL Y I N STUD Y 

 NECROPSIED 

 EXAMINE D HISTOPATHOLOGICALL Y 

10 

10 

10 

50 

50 

50 

50 

49 

49 

INTEGUMENTAR Y SYSTE M 

*SKI N 

SARCCMA , NO S 

(10) (50) 

1 (2%) 

(49) 

RESPIRATOR Y SYSTE M 

*LUN G 

ALVECLAR/BRONCHIOLA R ADENOM A 

&LVEOLAR/BRONCHIOLA R CARCINOM A 

(10) 

1 (10*) 

(49) 

4

1

 (8%) 

 (2X) 

(48) 

2

1

 (4«) 

 (2%) 

HEMATOPOIETIC SYSTE M 

*MULTIPLE ORGAN S 

MALIG.LYMPHOMA , HISTIOCYTIC

LYMPHOCYTIC LEUKEMI A 

 TYP E 

(10) (50) (49) 

1

1

 (2X) 

(2%) 

CIRCULATOR Y SYSTEM 

NON E 

DIGESTIVE SYSTEM 

f LIVER 

HEPATOCELLULA R ADENOM A 

NEOPLASTIC NODUL E 

HEPATOCELLULA R CARCINOM A 

(10) 

1

a

 (10X) 

 (40X) 

(49) 

2

11

 (4*) 

 (22X) 

(49) 

2

2

4

 (4%) 

 (i*X) 

 (8X) 

URINAR Y SYSTE M 

NON E _ „ „, 

f NUMBE R

* NUMBE R

 OF ANIMAL S

 OF ANIMAL S

 WITH TISSUE

 NECItOPSIED 

 EXAMINE D MICROSCOPICALLY 

49 
TABLE B1. MALE MICE: NEOPLASMS (CONTINUED) 

CONTROL LOU DOSE 

ENDOCRIN E SYSTE M 

#THYHOI D (10) (48) 

FCL1ICULAB-CELL ADENOM A 

REPRODUCTIV E SYSTE M 

tTESTIS (10) (48) 

INTEHSTITIAL-CELL TUHOR 1 (10%) 

SEMINOMA/EYSGERMINON A 

NERVCU S SYSTEM 

NON E 

SPECIAL SENS E ORGAN S 

*EYE/LACRIMA L GLAN D (10) (50) 

PAPILLAR Y ADENOM A 

MUSCULOSKEIETA L SYSTEM 

NON E 

BODY CAVITIES 

NON E 

ALL OTHER SYSTEMS 

_NON E 

t NUMBE R OF ANIMAL S WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMAL S NECROPSIED 

HIGH DOSE 

(44) 

2 <5X) 

(48) 

1 (2%) 

(49) 

1 (2*) 

50 
TABLE B1.MALE MICE: NEOPLASMS (CONTINUED)

 

CONTROL LOH DOSE HIGH DOSE 

ANIMA L DISPOSITION SUMMAR Y 

ANIMAL S INITIALL Y III STUDY 10 50 50

 

NATURAL DEATHS 3

 

MORIBUN D SACRIFICE 1 7 7

 

SCHEDULED SACRIFICE 

ACCIDENTALL Y KILLE D 

TERMINA L SACRIFICE 9 43 «0

 

ANIMA L MISSING 

3 INCLUDES AUTOLYZE D ANIMAL S 

TUMO R SUMMAR Y 

TOTAL ANIMALS WITH PRIMARY TUMORS* 5 18 1« 

TOTAL PRIMAR Y TUMOR S 7 19 17

 

TOTAL ANIMAL S WIT H BENIG N TUMORS 2 U U 

TOTAL BENIGN TUMORS 2 U 7 

TOTA L ANIMAL S WIT H MALIGNAN T TUMORS 4 13 8 

TCTA L MALIGNAN T TUMOR S U 13 8 

TOTAL ANIMAL S WIT H SECONDAR Y TU10RS# 

TOTAL SECONDAR Y TUMOR S 

TOTA L ANIMAL S WIT H TUMOR S UNCERTAIN ­

BENIG N O R MALIGNAN T 1 2 2

 

TOTAL UNCERTAI N TUMORS 1 2 2

 

T O T A L ANIMAL S W I T H TUMOR S UNCERTAIN UNCERTAIN­-

PRIMAR Y CR METASTATI METASTATIC 

T O T A L UNCERTAI UNCERTAI N TUMORS

* PRIMAR Y TUMORS : ALL TUMOR S EXCEP T SECONDARY TUMORS 

* SECONDAR Y TUMORS : METASTATIC TUMOR S O R TUMOR S INVASIV E INTO A N ADJACENT ORGA N 

51 
TABLE B2.

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE MICE 

FEDPICLORAMINTHEDIET 

CONTROL LOW DOSE HIGH DOSE 

ANIMAL S

A8IMAI S

ANIMAL S

 INITIALLY IN STUDY 

 NECROPSIE D 

 EXAMINE D HISTOPATHOLOGICALLY 

10 

10 

10 

50 

< »9 

U9 

50 

50 

50 

INTEGUMENTAR Y SYSTE M 

NON E 

RESFIRATCR Y SYSTEM 

tLUN G 

ALVECLAR/BRONCHIOLA R

OSTEOSARCOMA 

 ADENOM A 

(10) 

1 (10%) 

(49) 

1 (2X ) 

1 (2X) 

(50) 

HEMATOPOIETIC SYSTE M 

*MULTIPLE ORGAN S 

LYMFHCCYTI C LEUKEMI A 

(10) (a 9) 

2 («X ) 

(50) 

CIRCULATOR Y SYSTE M 

NON E 

DIGESTIV E SYSTEM 

tLIVE R 

HEPATOCELLULA R CARCINOM A 

(10) (U9 ) (50) 

1 (2X) 

URINAH Y SYSTE M 

NON E 

ENDOCRIN E SYSTE M 

tTHYROI D 

FOLLICULAR-CEL L ADENOM A 

(10) (141) 

J_J2*1__ . 

(U5) 

1 12XL 

# NU1BES

* NUMBE R

 OF ANIMAL S WITH TISSUE

 OF ANIMAL S NECKOPSIE D 

 EXAMINE D MICROSCOPICALLY 

52 
TABLE B2. FEMALE MICE: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

REPRODUCTIV E SYSTEM 

*MAM«AR Y GLAND (10) (49) (50) 

ADENOCARCINOMA , SOS 1 (2X) 1 (2X) 

NERVOU S SYSTE M 

NON E 

SPECIA L SENS E ORGANS 

NON E 

MUSCULOSKELETAL SYSTEM 

NON E 

BODY CAVITIES 

NONE 

A LL OTHER SYSTEMS 

NON E 

ANIRA L DISPOSITION SUMMAR Y 

ANIMAL S INITIALLY IN STUDY 10 50 50 

NATURA L DEATHS 2 

MORIBUN D SACRIFICE 7 3 

SCHEDULED SACRIFICE 

ACCIDENTALLY KILLED 

TERMINA L SACRIFICE 10 41 47 

ANIMA L MISSING 

a^INCLODES AUT21YZE.DJUIJ1JALS 

t NUMBER OF ANIMAL S WITH TISSUE EXAMINED MICROSCOPICALLY 

* NUMBER OF ANIMALS NECROPSIED 

53 
TABLE B2. FEMALE MICE: NEOPLASMS (CONTINUED)

 

CONTROL LOW DOSE HIGH DOSE 

TUMO<? SUMMAR Y 

TOTAL ANIMAL S WITH PHIMAR Y TUMORS* 1 6 3

 

TOTAL PRIMARY TUMORS 1 6 3

 

TOTAL ANIMAL S WIT H BENIG N TUMORS 1 2 1

 

TOTAL BENIGN TUMORS 1 2 1

 

TOTAL ANIMAL S WITH MALIGNAN T TUMORS 4 2

 

TOTAL MALIGNAN T TUMORS U 2 

TOTAL ANIMAL S WIT H SECONDARY TUMORS* 

TOTAL SECONDAR Y TUMORS 

TOTAL ANIMAL S WITH TUMOR S UNCERTAIN ­

BENIG N O R MALIGNAN T 

TOTAL UNCERTAI N TUMORS 

TOTA L ANIMAL S WIT H TUMOR S UNCERTAIN ­

PRIMAR Y CR METASTATIC 

TOTA L UNCERTAI N TUMORS 

* PPIflAR Y TUMORS: ALL TUTORS EXCEPT SECONDARY TUMORS 

* SECONDARY TUMORS: METASTATIC TUMORS OR TUMORS INVASIV E INTO AN ADJACENT ORGA N 

54
 
APPENDIX C
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS
 

IN RATS FED PICLORAM IN THE DIET
 

55
 

TABLE C1.

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN MALE RATS 

FEDPICLORAMINTHEDIET 

CONTROL LOW DOSE HIGH DOSE 

ANIKAL S INITIALLY IN STUD Y 10 50 

ANIMAL S NECRGPSIED 10 50 

ANIMAL S EXAMINE D HISTOPATHOLOGICALLY 10

 50 

INTEGUMENTAR Y SYSTEM 

*SKIN (10) (50) 

EPIDERMAL INCLUSION CYST 

GRANULATION , TISSUE 1 (10%) 1 (2%) 

*SUBCUT TISSUE (10) (50) 

EDEMA , NOS 

GRANtJLOMA , NOS 1 (2%) 

GRANULATION , TISSUE 1 (2%) 

RESPIRATOR Y SYSTEM 

*LUNG (10) (49)

 

EDEMA , NOS 1 (10%) 

HEMATOPOIETIC SYSTEM 

tSPLEEN (10) (50) 

HYPERPLASIA , NOS 1 (2%) 

HEMATOPOIESIS 2 (4%) 

•CERVICAL LYMP H NODE (10) (44) 

INFLAMMATION , NOS 1 (10%) 

INFLAMMATION , CHRONIC 1 (10%) 

HYPERPLASIA , NOS 1 (2%) 

CIRCULATORY SYSTEM 

tHEART (10) (49) 

ARTERIOSCLEROSIS, NOS 

CALCIFICATION, METASTATIC 1 (2%) 

*HEART/ATRIUM (10) (49) 

THKCMBJISj^OIGlNIJED 

t NUMBER OF ANIMAL S WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBER OF ANIMALS NECROPSIED 

57 

50 

50 

49 

(50) 

1 (2%) 

(50) 

1 (2%) 

(50) 

(50) 

1 (2%) 

(45) 

(50) 

1 (2%) 

(50) 

J_i2JL 
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED)

 

HIGH DOSE 

(50) 

4 (8%) 

2 (4%) 

1 (2%) 

1 (2%) 

(50) 

3 (6%) 

(50) 

(49) 

9 (18%) 

5 (10%) 

(50) 

1 (2%) 

1 (2%) 

2 (4%) 

(49) 

1 (2%) 

(49) 

1 (2%) 

(46) 

1 (2%) 

1 (2%) 

4 (9%) 

(46) 

1 (2%) 

(46) 

(40) 

• MYOCARDIU M 

PIBROSIS, FOCAL 

PIBROSIS, DIFFUSE 

CALCIFICATION, NOS 

CALCIFICATION, FOCAL 

*AORTA 

SPDIAL CALCIFICATION 

*CORONARY ARTERY 

ARTERIOSCLEROSIS, NOS 

DIGESTIVE SYSTEM 

•LIVER 

INFLAMMATION ,

METAMORPHOSIS

FOCAL CELLULAR

*BIIE DUCT 

INFLAMMATION ,

 FOCAL GRANULOHATO U 

 FATTY 

 CHANGE 

 CHRONIC FOCAL 

HYPERPLASIA, NOS 

HYPERPLASIA, FOCAL 

HYPERPLASIA, DIFFUSE 

• PANCREA S 

ARTERIOSCLEROSIS, NOS 

•PANCREATIC ACINUS 

ATROPHY , NOS 

•STCMACH 

ULCER, NOS 

EROSION 

CALCIFICATION, NOS 

•GASTRIC HOCOSA 

CALCIFICATION, NOS 

•GASTRIC BUSCULARIS 

CALCIFICATION, NOS 

•CECOM 

* NU1BEH OF ANIMAL S WITH TISSUE

* NU1BER OF ANIMAL S NECSOPSIED 

CONTROL 

(10) 

1 (10%) 

(10) 

(10)

1 (10%) 

(10) 

2 (20%) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(6) 

LOW DOSE 

(49) 

3 (6%) 

1 (2%) 

(50) 

(50) 

(49) 

1 (2%) 

12 (24%) 

(50) 

1 (2%) 

(49) 

(49) 

(50) 

1 (2%) 

(50) 

(50) 

1 (2%) 

(41) 

 EXAMINE D MICROSCOPICALLY 

58 
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE 

URINAR Y SYSTEM 

IKIDNEY (10) (50) 

CALCULUS, NOS 1 <2X) 

GLOHERULONEPHRITIS, NOS 3 (30*) 

PYELONEPHRITIS, ACUTE 1 (2X) 

INFL AMB ATION , C H30N 1C 5 (50*) 12 (24X) 

NEPHROSIS, DOS 1 (2*) 

• URINAR Y BLADDER (9) (l»7) 

INFLAMMATION , ACUT E SUPPURATIV E 1 (2X) 

ENDOCRIN E SYSTEM 

• PITUITAR Y (9) (U6 ) 

CYST, NOS 4 (9*) 

HEMORRHAG E 

DEGENERATION, CYSTIC 1 (2X) 

HYPERPLASIA , FOCAL 1 (11*) 1 (2*) 

• ADRENA L (10) («9) 

CYST, NOS 1 (2*) 

HEMORRHAGE 1 (2*) 

DEGENERATION , CYSTIC 1 (10*) 2 (<»*) 

METAMORPHOSI S FATTY 1 (2*) 

ANGIECTASIS 1 (2*) 

• ADRENA L CORTEX (10) (49) 

DEGENERATION , NOS 2 (4*) 

DEGENERATION , CYSTIC 

METAMORPHOSI S FATTY 

HYPERPLASIA , FOCAL 3 (6*) 

•THYROID (9) (U7) 

CYSTIC FOLLICLES 

HYPERPLASIA , C-C2LL 6 (13*) 

HYPERPLASIA , FOLLICULAR-C ELL 5 (11*) 

•PARATHYROID (6) (32) 

HYPE3PLASIA , NOS 1 (3*) 

REPRODUCTIV E SYSTEM 

*MAMMAR Y GLAN D (10) (50) 

ADENCS.IS_ 

# NUMBE R OF ANIMAL S HITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMAL S NECROPSIED 

HIGH OOSE 

(50) 

26 (52X) 

(«6) 

(i»5) 

10 (22X) 

1 (2X) 

2 (OX) 

(49) 

1 (2X) 

1 (2*) 

(«9) 

1 (2X) 

1 (2X) 

2 (UX) 

(«9) 

1 (2X) 

7 (1UX) 

6 (12X) 

(35) 

7 (20X) 

(50) 

-I-12S1­

59 
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE 

•PROSTATE (9) (47) 

INFLAMMATION, SOPPOSATIVE 2 (4*) 

INFLAMHATION , ACUTE SUPPORATIVE 1 (2*) 

INFLAMMATION ACUTE AMD CHRONIC 

CALCIFICATION, NOS 

ATROPHY , NOS 1 (2K) 

tTESTIS (10) (50) 

PERIAHTERITI S 1 (2X) 

ATROPHY, NOS 5 (50*) 7 (1HX) 

NERVOUS SYSTEM 

NONE 

SPECIAL SESSE ORGANS 

*EYE (10) (50)

 

CATARACT 1 (10*)

 

MOSCULOSKE1ETAL SYSTEM 

*BONE (10) (50)

 

CSTECFOROSIS 

BODY CAVITIE S 

*PLEUH A (10) (50)

 

INFLAHHATION, CHRONIC FOCAL 

*MESENTERY (10) (50) 

PERIASTERITIS 2 (20X) 2 (4*) 

ARTERIOSCLEROSIS, NOS 1 (10*) 

A LL OTHER SYSTEMS 

*MULTIPLE ORGAN S (10) (50)

 

_ PIBIASTE.RITIS 

I NUMBE 3 OF ANIMAL S HITH TISSUE EXAMINE D MICPOSCOP ICALLY 

* NUMBER CF ANIMALS NECROPSIED 

HIGH DOSE 

(48) 

1 (2*) 

1 (2*) 

1 <2X) 

1 (2*) 

(50) 

3 (6*) 

14 (28X) 

(50) 

(50) 

1 (2X) 

(50) 

1 (2X) 

(50) 

7 (14X) 

1 (2*) 

(50) 

1.12iL_ 

60 
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED)

 

CONTROL LOW DOSE HIGH DOSE 

SPECIAL KCRFHOLOGY SUMHARY 

NC LESION REPORTE D 1 11 2 

AUTO/NECROPSY/NO HISTO 1 

» NUMBER OP ANIMALS WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OP ANIMAL S NECROPSIE D 

61 
TABLE C2.

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN FEMALE RATS 

FED PICLORAM IN THE DIET 

CONTROL LOW DOSE
 

ANIMALS INITIALLY IN STUDY 10 50
 

ANIHAIS NECRCPSIED 10 50
 

ANIMALS EXAMINED HISTOPATHOLOGICALLY 10 50
 

INTEGUMENTARY SYSTEM
 

NONE
 

RESPIEATCBY SYSTEM
 

NONE
 

HEMATOPOIETIC SYSTEM
 

tSPLEEN (10) (49)
 

HEMATOFOIESIS
 

MYELOID METAPLASIA
 

tSPLENIC RED PULP (10) (49)
 

ATRCPHY, NOS 1 (2X)
 

•CERVICAL LYMPH NODE (8) (46)
 

INFLAMMATION, NOS 1 (13X)
 

CIRCULATCRY SYSTEM
 

•MYOCARDIUM	 (10) (50)
 

PIBRCSIS, FOCAL 1 (2X)
 

DIGESTIVE SYSTEM
 

«LIVER (10) (50)
 

NECROSIS, FOCAL 1 (2X)
 

METAMORPHOSIS FATTY
 

FOCAL CELLULAR CHANGE 1 (10X) e (16%)
 

3YEL9ID METAPLASIA , , „ __


* NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

* NUMBE R OF ANIMAL S NECROPSIED 

62 

HIGH DOSE
 

50
 

50
 

49
 

(49)
 

1 (2X)
 

1 (2X)
 

(49)
 

(46)
 

(49)
 

1 (2X)
 

(49)
 

2 (4%)
 

18 (37%)
 

 __ 1 J2IU
 
TABLE C2. FEMALE RATS: NONNEOPLASTIC LESIONS (CONTINUED)

 

*BIIE DUCT 

FIBROSIS 

HYPERPLASIA , NOS 

HYPERPLASIA , FOCAL 

•PANCREATIC ACINU S 

ATROPHY , FOCAL 

*STCHAC H 

ULCER, flO S 

ORINAR Y SYSTE M 

IKIDKEY 

CYST, NOS 

INFLAMMATION , CHRONIC 

FIBROSIS, FOCAL 

ENDOCRIN E SYSTE M 

• PITUITARY 

CYST, NOS 

CONGESTION, NOS 

HEMORRHAG E 

HYPERPLASIA , NO S 

HYPERPLASIA , FOCAL 

*ADHENAL 

THROKBCSIS , NO S 

HEMOR?HAG E 

DEGENERATION , CYSTIC 

• ADRENA L CORTE X 

HEMORRHAG E 

DEGENERATION , NO S 

DEGENERATION , CYSTIC 

HYPEPPLASIA , FOCAL 

#THYSOI D 

HYPEPPLASIA , C-CELL 

HYPEEPLASIA i FOLLICULAS-CELL 

* NUMBE R OF ANIMAL S WIT H TISSUE

* NUMBE R OF ANIMAL S NECROPSIE D 

. 

HIGH DOSE 

(50) 

6 (12*) 

1 (2*) 

(49) 

(48) 

1 (2X) 

(48) 

4 (8*) 

1 (2*) 

(46) 

1 (2*) 

1 (2*) 

(48) 

5 (10*) 

2 (4*) 

(48) 

6 (13*) 

1 (2*) 

(46) 

6 (13*) 

6_J13*1, 

CONTROL 

(10) 

(10) 

(10) 

(10) 

1

(9) 

1

1

1

1

(8) 

1

(8)

1

(9) 

 (10*) 

 (11*) 

 (11*) 

 (11*) 

 (11*) 

 (13*) 

 (13*) 

LOH DOSE 

(50) 

2 (I**1) 

3 (6*) 

1 (2*) 

(U7 ) 

1 (2*) 

(«9) 

(48) 

1 (2*) 

2 (4*) 

(48) 

3 (6*) 

1 (2*) 

(50) 

5 (10*) 

3 (6X) 

(50) 

2 (4*) 

1 (2*) 

2 (4«) 

(46) 

8 (17*) 

1_12*L_

 EXAMINE D MICROSCOPICALLY 

63 
TABLE C2. FEMALE RATS: NONNEOPLASTIC LESIONS (CONTINUED)

 

REPRCEUCTIV E SYSTEH 

*MAMMAR Y GLAN D 

HYPERPLASIA , NO S 

DYSPLASIA , NOS 

ADENOSIS 

tUTERU S 

METAPLASIA, SQUAMOUS 

tOVARY 

CYST, NOS 

NERVOU S SYSTEM 

NONE 

SPECIAL SENSE ORGANS 

NONE 

HOSCULOSKE1ETAL SYSTEM 

NONE 

BODY CAVITIES 

*NESENTERY 

PERIARTERITI S 

ALL OTHER SYSTEMS 

NONE 

SPECIAL MORPHOLOGY SUMMAR Y 

NO LESION REPORTED 

AUTO/NECROPSY/NO HISTO 

# NUMBER OF ANIHALS HITH TISSUE

* NUMBE R OF ANIMALS NECROPSIED 

CONTROL LOW DOSE 

(10) (50) 

6 (12S) 

1 <2X) 

1 (10%) 

(10) (U8 ) 

1 (2%) 

(10) (U7) 

1 (2%) 

(10) (50) 

2

8 

 EXAMINED MICROSCOPICALLY 

64 

HIG H DOSE 

(50) 

6 (12%) 

(«5) 

(U8) 

(50) 

1 <2X) 

7 

1 
APPENDIX D
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS
 

IN MICE FED PICLORAM IN THE DIET
 

65
 

TABLE D1.

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN MALE MICE 

FEDPICLORAM INTHE DIET 

CONTROL LOW DOSE HIGH DOSE
 

ANIMALS INITIALLY IN STUDY 10 50 50
 

ANIMALS SECP.CPSIED 10 50 49
 

ANIMALS EXAMINED HISTOPATHOLOGICALLY 10 50 49
 

INTEGUMENTARY SYS1E1
 

*SKIN (10) (50) (49)
 

INFLAMMATION, NO S 1 (2*)
 

ULCER, NOS 2 («%) 1 (2%)
 

RESPIRATORY SYSTEM
 

iLUNG (10) (49) (48)
 

INFLAMMATION, CHRONIC 1 (2%)
 

HYPERPLASIA, ADENOMATOUS 1 (2%)
 

HEMATOPOIETIC SYSTEM
 

NONE
 

CIRCULATORY SYSTEM
 

NONE
 

DIGESTIVE SYSTEM
 

*STCMACH (10) (49) (48)
 

DIVERTICULUM 1 (2X)
 

OR1NARY SYSTEM
 

NONE
 

ENDOCRINE SYSTEM
 

ITHYROID (10) (48) (44)
 

FCiLICOLAS CYST, NOS 1 (2X)
 

HYPERPLASIA, ADENOBATOOS 1 (10%)
 

HYPERPLASIA^ FOLLICUI,AEz£ELL__ . 1 Jiil_
 

I NUMBER OF ANIMAL S WITH TISSOE EXAMINE D MICROSCOPICALLY 

* NUMBER OF ANIMAL S NECHOPSIED 

67 
TABLE 01. MALE MICE: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE HIG H DOSE 

REPF.OEOCTIVE SYSTEM 

NONE 

NERVOOS SYSTE M 

NON E 

SPECIAL SENS E ORGAN S 

HON E 

HUSCtUOSKEIETAL SYSTEH 

NONE 

BODY CAVITIES 

NONE 

ALL OTHER SYSTEMS 

NON E

S P E C I AS P E C I AL HORPHOLOG HORPHOLOGY SUMHARMAY 

NO LESION REPORTE REPORTED 5 29 3300 

ADTOLYSIS/NO NECROPS NECROPSY 1

t NUMBE R OF ANIMAL S WITH TISSUE EXAMINE D MICROSCOPICALLY 

* NUMBE R OF ANIMAL S MECROPSIED 

68 
TABLE 02.

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN FEMALE MICE 

FED PICLORAMIN THE DIET 

ANIMAL S INITIALL Y IN STUD Y 

ANIMAL S NECROPSIE D 

ANIMAL S EXAMINE D HISTOPATHOLOGIC ALLY 

INTEGUMENTAR Y SYSTEM 

NON E 

RESPIRATORY SYSTEM 

tLUN G 

INFLAMMATION , CHEONIC 

HEMATOPOIETIC SYSTEM 

#SPLEEN 

CONGESTION, NOS 

HYPERPLASIA , LYBPHOID 

CIRCULATOR Y SYSTEM 

NONE 

DIGESTIVE SYSTEM 

tLIVER 

INFLAMMATION , FOCAL 

INFLAMMATION , ACUTE FOCAL 

BASOPHILIC CYTO CHANG E 

I PANCREA S 

DILATATION/DUCTS 

INFLAMMATION , NOS 

#COLC N 

tJlgJHj NOS, 

CONTROL 

10 

10 

10 

(10) 

1 (10*) 

0) 

(10) 

(9) 

(3) 

LOH DOSE HIGH DOSE 

50 50

 

U 9 50 

«9 50 

(49) (50) 

(48) (50) 

1 (2X) 

1 (2%) 1 (2X) 

(i»9) (50)

3 (6*) 

1 (2*) 

1 (2X) 

(09) (50) 

1 (2«) 1 (2*) 

(1) 

J-.U&2X1 

f NUMBER OF ANIMAL S HITS TISSUE EXAMINED MICROSCOPICALLY 

* NUMBER OF ANIMAL S NECROPSIED 

69 
TABLE 02. FEMALE MICE: NONNEOPLASTIC LESIONS (CONTINUED)

 

LOW DOSE HIGH DOSE 

(1»9) 

(47) 

(«7) 

(47) 

16 (3H%) 

(a 9) 

1 (2X) 

URINAR Y SYSTEM 

tKIDNE Y 

INFLAMMATION, CHRONIC 

ENDOCRIN E SYSTE M 

#THYROID 

FCLLICULAR CYST, NOS 

INFLAMMATION , FOCAL GRANULOMATO U 

REPRODUCTIVE SYSTEM 

#UTSRUS/FNDC«ETRID M 

HYPERPLASIA , CYSTIC 

* OVARY 

CYST, NOS 

FOLLICOLAR CYST, NOS 

INFLAMMATION, NOS 

INFLAMMATION , SUPPURATIVE 

NERVOOS SYSTEM 

#BRAI N 

HYDRCCEPHALOS , NOS 

CORPORA AMYLACEA 

SPECIAL SENS E ORGAN S 

NONE 

M'JSCOLOSKEIETA L SYSTEM 

NON E 

BODY CAVITIES 

NON E 

A LL OTHER SYSTEMS 

NON E 

# NUMBER OF ANIMAL S WITH TISSUE EXAHINED MICROSCOPICALLY 

* NUMBE R OF ANIMAL S NECROPSIED 

CONTROL 

(10) 

(10) 

(10)

2 (20X) 

(10) 

2 (20X) 

(10) 

1 (10X) 

(50) 

1

(US) 

1

1

(U7) 

(49) 

1

9

5

(49)

 (2%) 

 (2«) 

 (2«) 

 (2«) 

 (18%) 

 (10*) 

70 
TABLE D2. FEMALE MICE: NONNEOPLASTIC LESIONS (CONTINUED)

 

COHTROL LOW DOSE HIGH DOSE 

SPECIAL MORPHOLOGY SUMMAR Y 

NO LESIOH REPORTED 5 27 26 

MJTOLYSIS/NO NECROPSY 1 

* NUMBER OF ANIMALS WITH TISSUE EXAMINE E MICROSCOPICALLY 

* NUMBE R CP ANIMAL S NECPOPSIE D 

71 

APPENDIX E
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS
 

IN RATS FED PICLORAM IN THE DIET
 

73
 

Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Picloram in the Diet3
 

Topography: Morphology 

Matched 

Control 

Pooled 

Control 

Low 

Dose 

High 

Dose 

Spleen: Hemangioma" 0/10 (0.00) 1/36 (0.03) 3/50 (0.06) 1/50 (0.02) 

P Values0>d N.S. N.S. N.S. N.S. 

Relative Risk (Matched Control)^ 

Lower Limit 

Upper Limit 

Infinite 

0.134 

Infinite 

Infinite 

0.012 

Infinite 

Relative Risk (Pooled Control)f 

Lower Limit 

Upper Limit 

2.160 

0.183 

111.051 

0.720 

0.009 

55.415 

Weeks to First Observed Tumor —_ 113 106 

Liver: Neoplastic Nodule 0/10 (0.00) 0/38 (0.00) 3/49 (0.06) 0/49 (0.00) 

P Values0 » d N.S. N.S. N.S. N.S. 

Departure from Linear Trend6 P = 0.020 

Relative Risk (Matched Control)f 

Lower Limit 

Upper Limit 

Infinite 

0.137 

Infinite 

__ 

— 

— 

Relative Risk (Pooled Control)^ 

Lower Limit 

Upper Limit 

Infinite 

0.470 

Infinite 

— 

— 

— 

Weeks to First Observed Tumor — 113 — 
Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Picloram in the Diet3
 

(continued)
 

Topography: Morphology 

Matched 

Control 

Pooled 

Control 

Low 

Dose 

High 

Dose 

Pituitary:

Adenoma 

 Chromophobe 

2/9 (0.22) 9/36 (0.25) 2/46 (0.04) 9/45 (0.20) 

P Values0»d N.S. N.S. P = 0.008**(N) N.S. 

Departure from Linear Trend6 P = 0.033 P = 0.007 

Relative Risk (Matched Control)f 

Lower Limit 

Upper Limit 

0.196 

0.018 

2.519 

0.900 

0.250 

7.901 

Relative Risk (Pooled Control)f 

Lower Limit 

Upper Limit 

0.174 

0.019 

0.776 

0.800 

0.318 

2.042 

Weeks to First Observed Tumor 113 113 83 
Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Picloram in the Dieta
 

(continued)
 

Topography: Morphology
 

Thyroid: C-cell Adenomab
 

P Values0 >d
 

Departure from Linear Trend6
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)^
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Matched
 

Control
 

0/9 (0.00)
 

N.S.
 

P = 0.042
 

—
 

Pooled
 

Control
 

1/36 (0.03)
 

N.S.
 

P = 0.018
 

Low
 

Dose
 

6/47 (0.13)
 

N.S.
 

Infinite
 

0.347
 

Infinite
 

4.596
 

0.595
 

206.379
 

113
 

High
 

Dose
 

1/49 (0.02)
 

N.S.
 

Infinite
 

0.011
 

Infinite
 

0.735
 

0.010
 

56.525
 

113
 
Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Picloram in the Diet3
 

(continued)
 

Matched Pooled Low High 

Topography: Morphology Control Control Dose Dose 

Adrenal: Cortical Adenoma'3 0/10 (0.00) 0/36 (0.00) 2/49 (0.04) 0/49 (0.00) 

P Values0 » d N.S. N.S. N.S. N.S. 

__ 

Relative Risk (Matched Control)* Infinite 

Lower Limit 0.067 — Upper Limit Infinite — __ 

Relative Risk (Pooled Control)* Infinite 

Lower Limit 0.220 

Upper Limit Infinite — 

— 

Weeks to First Observed Tumor 83 — — a

Treated groups received time-weighted average doses of 7,437 or 14,875 ppm.
 

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

c

Beneath the incidence of tumors in a control group is the probability level for the Cochran—
 

Armitage test when P < 0.05 otherwise, not significant (N.S.) is indicated. Beneath the incidence of tumors in a treated group is the probability level for the Fisher exact test for the
 

comparison of that treated group with the matched-control group (*) or with the pooled-control
 

group (**) when P < 0.05 for either control group; otherwise, not significant (N.S.) is
 

indicated.
 

'^A negative trend (N) indicates a lower incidence in a treated group than in a control group.
 

e

The probability level for departure from linear trend is given when P < 0.05 for any comparison.
 

*The 95% confidence interval of the relative risk between each treated group and
 

the specified control group.
 
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

Fed Picloram in the Diet3
 

Topography: Morphology
 

Liver: Neoplastic Nodule
 

P Values0»d
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Pituitary: Chromophobe
 

Adenoma
 

P Values°»d
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)^
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Matched
 

Control
 

0/10 (0.00)
 

N.S.
 

——
 

0/9 (0.00)
 

N.S.
 

—
 

Pooled Low High 

Control Dose Dose 

0/39 (0.00) 5/50 (0.10) 7/49 (0.14) 

P = 0.016 N.S. P = 0.014** 

Infinite Infinite 

0.281 0.441 

Infinite Infinite 

Infinite Infinite 

0.989 1.557 

Infinite Infinite 

99 88 

4/37 (0.11) 7/48 (0.15) 7/46 (0.15) 

N.S. N.S. N.S. 

Infinite Infinite 

0.413 0.430 

Infinite Infinite 

1.349 1.408 

0.375 0.392 

5.873 6.116 

109 94 
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

Fed Picloram in the Diet3
 

(continued)
 

Topography: Morphology
 

Thyroid: C-cell Adenomab
 

P Values0»d
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Adrenal: Cortical Adenoma
 

P Values0»d
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)^
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Matched Pooled Low High 

Control Control Dose Dose 

0/9 (0.00) 1/38 (0.03) 3/46 (0.07) 7/46 (0.15) 

N.S. P = 0.029 N.S. N.S. 

Infinite Infinite 

0.132 0.430 

Infinite Infinite 

2.478 5.783 

0.209 0.796 

127.174 254.145 

__ 

113 114 

0/8 (0.00) 0/37 (0.00) 2/50 (0.04) 4/48 (0.08) 

N.S. N.S. N.S. N.S. 

Infinite Infinite 

0.054 0.179 

Infinite Infinite 

Infinite Infinite 

0.222 0.719 

Infinite Infinite 

81 104 — 
__ 

Table E2. Analyses of the Incidence of Primary Tumors in Female Rats 

(continued) 

Topography: Morphology
 

Mammaryj
 Gland:
 i
 

Fibroadenoma
 

P Values0 »d
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Uterus: Endometrial
 

Stromal Polyp
 

P Values0 »d
 

Relative Risk (Matched Control)^
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Fed Picloram in the Diet3 

Matched Pooled Low High 

Control Control Dose Dose 

0/10 (0.00) 7/39 (0.18) 6/50 (0.12) 4/50 (0.08) 

N.S. N.S. N.S. N.S. 

Infinite Infinite
 

0.356 0.206
 

Infinite Infinite
 

0.669 0.446
 

0.203 0.103
 

2.142 1.626
 

63 63
 

1/10 (0.10) 3/39 (0.08) 8/48 (0.17) 4/45 (0.09) 

N.S. N.S. N.S. N.S. 

1.667 0.889 

0.278 0.108 

72.240 42.792 

2.167 1.156 

0.565 0.208 

11.972 7.468 

113 81 104 
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

Fed Picloram in the Diet3
 

(continued)
 

a

Treated groups received time-weighted average doses of 7,437 or 14,875 ppm.
 

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

°Beneath the incidence of tumors in a control group is the probability level for the Cochran-


Armitage test when P < 0.05; otherwise, not significant (N.S.) is indicated. Beneath the incidence of tumors in a treated group is the probability level for the Fisher exact test for the
 

comparison of that treated group with the matched-control group (*) or with the pooled-control
 

group (**) when P < 0.05 for either control group; otherwise, not significant (N.S.) is
 

indicated.
 

"A negative trend (N) indicates a lower incidence in a treated group than in a control group.
 

e

The probability level for departure from linear trend is given when P < 0.05 for any comparison.
 

^The 95% confidence interval of the relative risk between each treated group and
 

the specified control group.
 
APPENDIX F
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS
 

IN MICE FED PICLORAM IN THE DIET
 

83
 

Table Fl. Analyses of the Incidence of Primary Tumors in Male Mice
 

Fed Picloram in the Diet3
 

Matched Pooled Low
 

Topography: Morphology Control Control Dose
 

Lung: Alveolar/Bronchiolar
 

Adenoma or Carcinoma 1/10 (0.10) 2/38 (0.05) 5/49 (0.10)
 

P Values0>d N.S. N.S. N.S.
 

Relative Risk (Matched Control)f 1.020
 

Lower Limit 0.141
 

Upper Limit 47.261
 

Relative Risk (Pooled Control)f 1.939
 

Lower Limit 0,339
 

Upper Limit 19.554
 

Weeks to First Observed Tumor 90 76
 

Liver: Hepatocellular Carcinoma 4/10 (0.40) 8/38 (0.21) 11/49 (0.22)
 

P Values0>d P = 0.007 (N) N.S. N.S.
 

Relative Risk (Matched Control)f 0.561
 

Lower Limit 0.235
 

Upper Limit 2.094
 

Relative Risk (Pooled Control)f 1.066
 

Lower Limit 0.437
 

Upper Limit 2.765
 

Weeks to First Observed Tumor 62 87
 

High
 

Dose
 

3/48 (0.06)
 

N.S.
 

0.625
 

0.061
 

32.146
 

1.188
 

0.143
 

13.675
 

91
 

4/49 (0.08)
 

P = 0.022* (N)
 

0.204
 

0.053
 

0.963
 

0.388
 

0.093
 

1.337
 

81
 
Table Fl. Analyses of the Indicence of Primary Tumors in Male Mice
 

Fed Picloram in the Diet3
 

(continued)
 

Topography: Morphology 

Matched 

Control 

Pooled 

Control 

Low 

Dose 

High 

Dose 

Liver: Hepatocellular Carcinoma 

or Adenoma or Neoplastic Nodule 5/10 (0.50) 9/38 (0.24) 13/49 (0.27) 8/49 (0.16) 

P Values0>d P = 0.020 (N) N.S. N.S. P = 0.033* (N) 

Relative Risk (Matched Control)f 

Lower Limit 

Upper Limit 

0.531 

0.264 

1.595 

0.327 

0.140 

1.077 

Relative Risk (Pooled Control)^ 

Lower Limit 

Upper Limit 

1.120 

0.501 

2.663 

0.689 

0.257 

1.827 

Weeks to First Observed Tumor 62 87 81 

a

Treated groups received time-weighted average doses of 2,531 or 5,062 ppm.
 

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

c

Beneath the incidence of tumors in a control group is the probability level for the Cochran-


Armitage test when P < 0.05; otherwise, not significant (N.S.) is indicated. Beneath the incidence of tumors in a treated group is the probability level for the Fisher exact test for the
 

comparison of that treated group with the matched-control group (*) or with the pooled-control
 

group (**) when P < 0.05 for either control group; otherwise, not significant (N.S.) is
 

indicated.
 

^A negative trend (N) indicates a lower incidence in a treated group than in a control group.
 

e

The probability level for departure from linear trend is given when P < 0.05 for any comparison.
 

fine 95% confidence interval of the relative risk between each treated group and
 

the specified control group.
 
__ 

__ 

Table F2. Analyses of the Incidence of Primary Tumors in Female Mice
 

Fed Picloram in the Diet3
 

Topography: Morphology
 

Lung: Alveolar/Bronchiolar
 

Adenoma
 

P Values0>d
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Liver: Hepatocellular
 

Carcinoma
 

P Values0 'd
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Relative Risk (Pooled Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Matched
 

Control
 

1/10 (0.10)
 

N.S.
 

90
 

0/10 (0.00)
 

N.S.
 

—
 

Pooled
 

Control
 

2/39 (0.05)
 

N.S.
 

3/39 (0.00)
 

N.S.
 

Low
 

Dose
 

1/49 (0.02)
 

N.S.
 

0.204
 

0.003
 

15.723
 

0.398
 

0.007
 

7.377
 

90
 

0/49 (0.00)
 

N.S.
 

—
 

—
 

0.000
 

0.000
 

1.321
 

—
 

High
 

Dose
 

0/50 (0.00)
 

N.S.
 

0.000
 

0.000
 

3.747
 

0.000
 

0.000
 

2.634
 

1/50 (0.02)
 

N.S.
 

Infinite
 

0.012
 

Infinite
 

0.260
 

0.005
 

3.097
 

91
 
Table F2. Analyses of the Incidence of Primary Tumors in Female Mice
 

Fed Picloram in the Diet3
 

(continued) 

a

Treated groups received time-weighted average dose of 2,531 or 5,062 ppm.
 

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

C

8eneath the incidence of tumors in a control group is the probability level for the Cochran-


Armitage test when P < 0.05; otherwise, not significant (N.S.) is indicated. Beneath the incidence of tumors in a treated group is the probability level for the Fisher exact test for the
 

comparison of that treated group with the matched-control group (*) or with the pooled-control
 

group (**) when P < 0.05 for either control group; otherwise, not significant (N.S.) is
 

indicated.
 

^A negative trend (N) indicates a lower incidence in a treated group than in a control group.
 

e

The probability level for departure from linear trend is given when P < 0.05 for any comparison.
 

'The 95% confidence interval of the relative risk between each treated group and
 

the specified control group.
 
APPENDIX G
 

ANALYSIS OF FORMULATED DIETS FOR
 

CONCENTRATIONS OF PICLORAM
 

89
 

APPENDIX G
 

Analysis of Formulated Diets for
 

Concentrations of Picloram
 

A 10-g sample of the dosage mixture to be analyzed was shaken
 

with 125 ml raethanol for 16 hours. The mixture was then filtered
 

through Celite with raethanol washes, and the combined methanol
 

solution was reduced to 10 ml. After appropriate dilutions, the
 

solution was quantitatively analyzed for picloram by gas-liquid
 

chromatography (electron capture detector, 10% DC-200 on Gas
 

Chrom Q column). External standards were used for calibrations,
 

and recoveries were determined with spiked samples.
 

Theoretical No. of Sample Coefficient of Range (ppm) 

Concentrations Samples Analytical Variation (%) 

in Diet (ppm) Mean (ppm) 

2,500 19 2,494 3.1% 2,340-2,670 

5,000 19 4,984 4.0% 4,660-5,400 

10,000 23 9,922 6.7% 9,200-11,200 

20,000 10 19,560 3.5% 18,700-20,600 

91
 

- U. S. GOVERNMENT PRINTING OFFICE • 1978 260 -899/3186 
DHEW Publication No. (NIH) 78-823