,, . ^- OHCA-C-073-
United States ^
Environmental Protection October iy«o
Agency Review Draft
4>EPA Research and
Development
EVALUATION OF THE POTENTIAL CARCINOGENICITY OF
1,4-DIOXANE
•(123-91-1)
Prepared for
OFFICE OF EMERGENCY AND REMEDIAL RESPONSE
OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
Prepared by
CARCINOGEN ASSESSMENT GROUP
Office of Health and
Environmental Assessment
Washington DC 20460
DRAFT — DO NOT QUOTE OR- CITE
THIS DOCUMENT IS A PRELIMINARY DRAFT. It has not been
formally released by the U.S. Environmental Protection
Agency and should not at this stage be construed to
represent Agency policy. It is being circulated for
comments on its technical accuracy and policy implica-
tions .
-------
DISCLAIMER
This document is a preliminary draft. It has not been formally released
by the U.S. Environmental Protection Agency and should not, at this
stage, be construed to represent Agency policy. It is being circulated
for comments on its technical merit and policy implications.
ii
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PREFACE
This report summarizes and evaluates information on the potential
carcinogenicity of a substance designated as hazardous under Section 101
(14) of the Comprehensive Environmental Response, Compensation and
Liability Act of 1980 (CERCLA). The methodology for obtaining and
evaluating this information is described in the EPA document "Methodology
for Evaluating Potential Carcinogenicity in Support of Reportable
Quantity Adjustments Pursuant to CERCLA Section 102," numbered
OHEA-C-073, December 1986. The EPA's Office of Emergency and Remedial
Response (OERR) has considered this evaluation in adjusting reportable
quantities pursuant to CERCLA Section 102. The methodology for adjusting
reportable quantities is described in the Technical Background Document
to Support Rulemaking Pursuant to CERCLA Section 102, Volume 1, March
1985, and is also summarized in Volume 2, August 1986, and Volume 3,
December 1986. The Agency's methodology for ranking CERCLA potential
carcinogens is described in detail in Volume 3.
These methodologies call for ranking carcinogens based on weight of
evidence (the strength of the case that a substance causes cancer in
humans) and carcinogenic potency (the strength of a substance to
cause cancer). This report focuses on the information used to classify
this substance's weight of evidence and estimate its carcinogenic
potency. It is a summary report and is not intended to be a complete
reference for health effects. Information on health and environmental
effects other than cancer are beyond the scope of this report. Ancillary
evidence, such as structure-activity relationships, short-term tests,
physiological, biochemical, and toxicological observations, and
comparative metabolism and kinetics, is included only to the extent that
it changes the weight of evidence. Nevertheless, the information in this
report is sufficient to classify this substance's weight of evidence and
estimate its carcinogenic potency.
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This report draws largely on information supplied by the Syracuse
Research Corporation under EPA Contract No. 68-03-3112. Due to the
amount of time elapsed between the original work performed by Syracuse
Research Corporation and the present effort to produce this document,
Environmental Monitoring & Services, Inc., under EPA Contract No.
68-03-3182, has been involved in an extensive review of all the Syracuse
documents. In somes cases, this review involved updating the information
provided but it was primarily a quality assurance effort. The present
document is a result of this effort.
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ABSTRACT
1,4-Dioxane is a probable human carcinogen, classified as weight-of-
evidence Group B2 under the EPA Proposed Guidelines for Carcinogen Risk
Assessment (U.S. EPA, 1984). Evidence on potential carcinogenicity from
animal studies is "Sufficient," and the evidence from human studies is
"Inadequate."
The potency factor (F) for 1,4-dioxane is estimated to be 0.034
(ag/kg/day)~ , placing it in potency group 3 according to the CAG'
methodology for evaluating potential carcinogens (U.S. EPA, 1986).
Combining the weight-of-evidence group and the potency group, 1,4-dioxane
is assigned a "LOW" hazard ranking for the purposes of RQ adjustment.
iv
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TABLE OF CONTENTS
1.0 WEIGHT OF EVIDENCE 1-1
1.1 ANIMAL STUDIES 1-1
1.2 HUMAN STUDIES 1-1
1.3 WEIGHT-OF-EVIDENCE ASSESSMENT 1-2
2.0 POTENCY 2-1
3.0 HAZARD RANKING 3-1
4.0 REFERENCES 4-1
APPENDIX A: SUMMARY OF SIGNIFICANT HUMAN AND/OR ANIMAL STUDIES
APPENDIX B: BIOASSAY OF 1,4-DIOXANE FOR POSSIBLE CARCINOGENICITY
TABLES
Table 2-1. DERIVATION OF POTENCY FACTOR (F) 2-2
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1.0 WEIGHT OF EVIDENCE
Chronic administration of 1,4-dioxane in the drinking water
(concentration ranged from 0.5 to 2.0%) has produced malignant tumors in
the nasal cavities (squamous cell carcinomas) and livers (hepatocellular
carcinomas) in multiple strains of rats (Argus et al., 1965; Hogh-Ligeti
et al., 1970; Argus et al., 1973; Kociba et al., 1974; NCI, 1978).
Similar administration of 1,4-dioxane induced hepatocellular carcinomas
and adenomas in mice (NCI, 1978), and gall bladder carcinomas in guinea
pigs (Hogh-Ligeti and Argus, 1970). No carcinogenic effect was observed,
however, in a well-designed single dose (111 ppm x 7 hours/day x 5
days/week) 2-year inhalation study with rats (Torkelson et al., 1974).
1,4-Dioxane was also active as a promoter in a two-stage skin
carcinogenesis study in mice (King et al., 1973). In this assay, a
single dermal application of 50 ug 7,12-dimethylbenzanthracene (DBMA) was
followed 1 week later by thrice weekly paintings of 1,4-dioxane
(unspecified concentration in acetone) for 60 weeks. Similar
applications of 1,4-dioxane without DMBA initiation did not result in a
significantly increased incidence of skin tumors.
1.2 HUMAN STUDIES
Three epidemiologic studies on workers exposed to dioxane are available.
Theiss et al. (1976) reported that 2 of 12 deaths among 74 workers were
due to cancer. The cases were a lamellar epithelial carcinoma in a
66-year-old man and myelofibrotic leukemia in a 71-year-old man. No
statistically significant increase was noted based on these few cases.
1-1
-------
Huffier et al. (1976) reported three cancer deaths (12 total deaths)
among 165 production and processing workers exposed to dioxane (and other
chemicals including vinyl chloride, trichloroethylene, and carbon
tetrachloride). A carcinoma of the stomach, an alveolar carcinoma and a
mediastinal malignancy were reported. These cancer deaths were not
different (p<0.05) from the expected numbers. In an unpublished study
reported to NIOSH by Dernehl (1976), four cancers were reported among 80
dioxane workers. One man died with colonic cancer, one with pulmonary
carcinoma, one with lymphosarcoma, and one with glioblastoma. Again, the
observed number of cancer cases was not different than expected cancer
deaths. It is noted as well that all cancers reported are of varied
origin and are not similar to those seen in animal models.
1.3 VEIGHT-OF-EVIDENCE ASSESSMENT
1,4-Dioxane produced nasal cavity and liver carcinomas in multiple
species of rats by chronic oral administration. The NCI (1978) incidence
data for nasal cavity carcinomas in female rats appear to be most
appropriate for quantitative risk estimation and derivation of a
carcinogenic potency factor (F). 1,4-Dioxane has additionally produced
carcinomas of the liver in mice and gall bladder in guinea pigs, and was
active as a promoter in a two-stage skin carcinogenesis study in mice.
This evidence is sufficient to classify 1,4-dioxane as an animal
carcinogen. The human epidemiologic evidence on 1,4-dioxane is
inadequate for assessing human carcinogenicity. Thus, using the EPA
Proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1984) for
evaluating the overall weight of evidence to humans, 1,4-dioxane is most
appropriately classified as a Group B2 chemical. Appendix A contains
summaries of the significant human and/or animal studies cited in this
review.
1-2
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2.0 POTENCY
The potency factor (F) for 1,4-dioxane is estimated to be 0.034
(•g/kg/day)~ , placing it in potency group 3 under the CAG's
methodology for evaluating potential carcinogens (U.S. EPA, 1986). Table
2-1 contains data from the selected study used to derive the potency
factor (F) for 1,4-dioxane. Appendix B contains the complete primary
reference for this study.
2-1
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Table 2-1. Derivation of Potency Factor(F)
Agent: 1,4-Dioxane
REFERENCE:
EXPOSURE ROUTE:
SPECIES:
STRAIN:
SEX:
VEHICLE OR PHYSICAL STATE:
BODY WEIGHT:*
DURATION OF TREATMENT:
DURATION OF STUDY:
LIFESPAN OF ANIMAL:b
TARGET ORGAN:
TUMOR TYPE:
EXPERIMENTAL DOSES/
EXPOSURE:
TRANSFORMED DOSES:°
(Bg/kg/day)
TUMOR INCIDENCE:
ANIMAL POTENCY:
(Bg/kg/day)
HUMAN POTENCY:
(Bg/kg/day)
NCI, 1978
oral
cat
Osborne-Mendel
F
drinking water
0.35 kg
T70 days
770 days (treated), 819 days (controls)
777 days (treated), 819 days (controls)
nasal turbinates
squaBous cell carcinoaa
11
640
8/35
0.0057
0 .034
0.5*
350
10/35
0%
0
0/34
Reported
As suaed
C NCI (1978) determined average daily doses froB the Bean consuaption of dioxane solution per week at intervals during the
second year of treataent. All transformed doses are provided directly from the reference.
• See Appendix B for a reproduction of the report on this study.
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3.0 HAZARD RANKING
Based on the veight-of-evidence Group B2 for 1,4-dioxane, and the potency
factor (F) of 0.0:
ranking of "LOW."
factor (F) of 0.034 (lag/kg/day) , 1,4-dioxane receives a hazard
3-1
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4.0 REFERENCES
Argus, M.F., J.C. Arcos and C. Hogh-Ligeti, 1965. Studies on the
Carcinogenic Activity of Protein-Denaturating Agents: Hepatocarcinogeni-
city of Dioxane. J. Nat. Cancer Inst. 35: 949-958.
Argus, M.F., R.S. Sohal, G.M. Bryant, C. Hogh-Ligeti and J.C. Arcos,
1973. Dose-response and Ultrastructural Alterations in Dioxane Carcino-
genesis. Influence of Methylcholanthrene on Acute Toxicity. Europ. J.
Cancer. 9: 237-243.
Buffler, P.A., S.M. Wood, L. Suarez and D.J. Kilian, 1976. Mortality
Follow-Up Among Workers Exposed to 1,4-Dioxane in the Chemical Industry.
Unpublished Report Submitted to NIOSH by the Epidemiology Program, Dept.
of Preventive Medicine and Community Health, The University of Texas
Medical Branch, Galveston, Texas. December 17, 1976. (Cited in NIOSH,
1977).
Dernehl, C.U., 1976. Epidemiology Study of Dioxane Workers. Written
communication to NIOSH, April, 1976. (Cited in NIOSH, 1977).
Hogh-Ligeti, C. and M.F. Argus, 1970. Effects of Carcinogens on the Lung
of Guinea Pigs. In; Nettesheim, P., M.G. Hanna, Jr., and J.W.
Deatherage, Jr., Eds., Conference on the Morphology of Experimental
Respiratory Carcinogenesis, Gatlinburg, Tennessee. AEC Symposium Series
No. 21, Springfield, VA, National Technical Information Service, pp.
267-279. (Summarized in IARC, 1976).
Hogh-Ligeti, C., M.F. Argus and J.C. Arcos, 1970. Induction of Carcin-
omas in the Nasal Cavity of Rats by Dioxane. Brit. J. Cancer. 24:
164-167.
4-1
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IARC (International Agency for Research on Cancer), 1976. 1,4-Dioxane.
In: Cadmium, Nickel, Some Epoxides, Miscellaneous Industrial Chemicals
and General Considerations of Volatile Anesthetics. IARC Monographs on
the Evaluation of Carcinogenic Risk of Chemicals to Man. Lyon, France:
WHO, IARC, Vol. 11, pp. 247-256.
King, M.E., A.M. Shefner, and R.R. Bates, 1973. Carcinogenesis Bioassay
of Chlorinated Dibenzodioxins and Related Chemicals. Environ. Health.
Persp. 5: 163-170.
Kociba, R.J., S.B. McCollister, C. Park, T.R. Torkelson and P.J. Gehring,
1974. 1,4-Dioxane. I. Results of a 2-Year Ingestion Study in Rats.
Toxicol. Appl. Pharmacol. 30: 275-286.
NCI (National Cancer Institute), 1978. Bioassay of 1,4-Dioxane for
Possible Carcinogenicity. NCI Carcinogens Tech. Rep. Ser. No. 80. DHEW
Publication No. (NIH) PB-285-711.
NIOSH (National Institute for Occupational Safety and Health), 1977.
Criteria for a Recommended Standard. Occupational Exposure to Dioxane.
DHEW(NIOSH) Publ. No. 77-226. U.S. Department of Health, Education, and
Welfare.
Theiss, A.M., E. Tress and I. Fleig, 1976. Industrial-Medical
Investigation Results in the Case of Workers Exposed to Dioxane.
Arbeitsmed. Sozialmed. Praveutivmed. 11: 35-46. (Cited in NIOSH, 1977).
Torkelson, T.R., B.K.J. Leong, R.J. Kociba, W.A. Richter, and P.J.
Gehring, 1974. 1,4-Dioxane. II. Results of a 2-Year Inhalation Study in
Rats. Toxicol. Appl. Pharmacol. 30: 287-298.
U.S. EPA (Environmental Protection Agency), 1984. Proposed Guidelines
for Carcinogen Assessment, 49 FR 46294-46307, November 23, 1984.
4-2
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U.S. EPA (Environmental Protection Agency), 1986. Methodology for
Evaluating Reportable Quantity Adjustments Pursuant to CERCLA Section
102, OHEA-C-073, June 1986.
4-3
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APPENDIX A
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Table A, AnlMl
Hgettts II, H-lttkosMltfW,
Reference: Argus at al., 1965
Exposure
Bout*
o
o
DOM
Speolaa/ or
Strain 3m Kxpoaure
rata/ H 1 .01*
Ulstar
rats/ H Of
Wlatar
Duration
or
Treataent
63 weaka
NA
Duration
of
Study
63 w««fca
63 weeka ,
•urity
of
Coapound
m
NA
Vahlola or
Phyaloal
Stata
drinking
water
Nil
Target Organ
liver
kHnay
heMtopoletla
oella
lya^hold
tissue
Tuanr
Typ«
tuax»rab
oaroinoHi0
Icukeala
lyaphoaa roooa
Tuanr
Inoldeno*
if value)
«/26
f/26
t/26
1/9
Strengtha or Study:
Veakneaa or Study:
Overall Adequacy:
QUALITY OF gflDBNCB
The compound was administered by a natural route of exposure for an acceptable portion of the llfeapan. Complete
autopalea were performed on all animals.
A single doae level was teated.
Adequate
• Total doae, 132 g.
b liver tuanra ranged fro« avail neoplaatlo nodulea to •ultlfooal bepatooellular oarolnoawa.
0 Transitional cell oarolnoav or the kidney pelvis.
NM « Not Reported; NA » Not Applicable
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Table A. Anlacl
Agent: 1,4-DiOMna
Reference: Bogh-Ligetl at •!., 1970s Argus «t al.t 1973
Exposure
Route
0
o
0
o
o
Dos*
Speolea/ or
Strain Sax Exposure
rata/ H 1.8f*
Spragua
Dawley
rata/ H 1 M*
Sprague
Dawley
rata/ N 1 .Of*
Sprague
Dawley
rate/ H 0.75**
Sprague
Dawley
rata/ H Of*
Sprague
Dawley
Duration
or
Treatment
13 Bonths
13 Bonths
13 aontha
13 Bonths
NA
Duration
or
Study
16 Bontha
16 Bonths
1
16 Bontha
16 Bontha
16 Bonths
Purity
or
CoBpound
Ml
MR
Nl
NR
NA
Vehicle or
Physical
State
drinking
water
drinking
water
drinking
water
drinking
water
drinking
water
Target Organ
naaal
liver
naaal
liver
naaal
liver
naaal
liver
naaal
liver
oavity
oavity
oavity
oavity
oavity
Tuanr
Typa
oaroinae»b'0
tUBors*'6
carcinoma"'0
tuBora '*
|y
tUBora*
carcinoma
tUBora*
oarclnoBa
tuBora
Tumor
Inoldenoe
(P value)
2/28-32
12/28-32
2/28-32
3/20-32
1/28-32
0/28-32
1/28-32
0/28-32
0/30
0/30
Strengths or Studyt
Weakneaa of Study:
Overall Adequacy:
QUALITY Of EVIDENCE
The ooBpound waa admlnlatered by a natural route or exposure at D levela or exposure. The anlBala were treated
and observed for a aigniricant portion or the llfeapan, and complete autopaiea were performed.
The naaal cavity waa atudled hiatologloally only in rata in which gross tuBora wvi
rata in each treatBent group waa not precisely stated.
Adequate.
re observed. The nuBber or
* Average dally water Intake waa 36 Bt.
b Itainly aquaBOua-oell oarclnoaBa, with areas containing adenoearolnomaa in 2 oaaaa.
0 The rata alao had hepatocellular oarclnoBaa.
d liver-cell hepatOBaa and hepatooellular carclnoBas.
' Hloroacoplo lesions described aa "Incipient hepatomaa" were observed In all treated groups.
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Table A. Anla*l
Mg«nt: 1l,l|~&lLC(xan*
Reference: Hogh-Llgetl and Argus, 1970 (Swaearlxed in IARC, 1976)
Exposure
Route
o
o
Species/
Strain Sex
guinea M
pig/ NR
guinea M
pig/ NR
Dose
or
Exposure
0.5-2**
Of
Duration
or
Treatment
23 aonths
NA
Duration
or
Study
28 Months
NR
Purity
or
Compound
NR
NR
Vehicle or
Physical
State
drinking
water
drinking
water
Target Organ
liver
gall bladder
liver
Tuaor
Type
hepatosM
carolnoMsa
tuawrs
Tuaor
Incidence
(P value)
3/22
2/22
0/10
QUALITY OP EVIDENCE
Strengths or Study:
Weakness or Study:
Overall Adequacy:
NR « Not Reported
NA • Not Applicable
The compound was administered by a natural route or exposure Tor a significant portion or the llfeapan.
Additional details regarding the design or results or this study were not presented In the available suavery.
Llsjlted.
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Table A. animal
•gent: 1, 1-Dloxane
Reference: Koolba et al., 1971
Dose Duration Duration Purity
Exposure Species/ or of of of
Route Strain Sex* Exposure Treatment Study* Compound
o rat/ mixed 1fb 21 months* 21 months MR
Sherman
o rat/ mixed 0.1f° 21 Months* 21 Months MR
Sherman
.
o rat/ Mixed O.OIf4 21 Months* 21 months MR
Sherman
o rat/ mixed Of NA 21 months NA
Sherman
Vehicle or
Physical
State
drinking
Mater
drinking
Mater
drinking
Mater
drinking
water
Target Organ
liver
nasal
cavity
liver
nasal
cavity
liver
nasal
cavity
liver
nasal
cavity
Tumor
Type
carcinoma
oholanglome
carcinoma'
carcinoma
oholangloma
carcinoma
carcinoma
oholangloma
carcinoma .
carolncmar
oholangloma
oholangloaarooma
carcinoma
Tumor
Incidence"
(P value)
10/66
(P<0.01)
2/66
3/66
(P.O. 05)
1/106
0/106
0/106
0/110
0/110
0/110
0/106
0/106
0/106
0/106
Strengths or Study:
Overall Adequacy:
Comments:
QUALITY OP EVIDENCE
Large groups of anlmala Mere exposed to 3 levels of compound For a
hlstopathologlo examinations Mere performed.
Adequate .
This study Is particularly Mail designed and reported.
jor portion of the llfeapan. Comprehensive
* 60 rats/sex/treatment group Mere tested.
b The mean dally dosages of dloxane, as determined from Mater consumption and body weight data from days 111-198, Mere 1015 Mg/kg/day
(males) and 1599 mg/kg/day (females).
0 The mean dally dosages of dloxane, as determined from Mater consumption and body weight data from daya 111-190, Mere 91 mg/kg/da>
(males) and 116 mg/kg/day (females).
A The mean dally dosages of dloxane, as determined from Mater consumption and body weight data from daya 111-196, Mere 9.6 Mg/kg/day
(males) and 19 mg/kg/day (females).
e The rats were exposed for up to 716 days.
f hepatocellular carcinomas.
' squamoua cell carcinomas.
h 126 of the 1)2 observed tumors In this study occurred in rats from the 12th to the 21th month. The number of rats expressed (I.e., the
effective number of rata) la therefore the number surviving at 12 months.
MR = Not Reported; NA * Not Applicable
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Table A. AnlMl
ttgwnt: 1w0-ftiosam*
Reference: NCI, 1978
Cipoaure Spec lea/
Mont* Strain
o rata/
Oaborne-
Mendel
o rats/
Oaborne-
Hendel
o rate/
Oaborne-
Hendel
o rata/
Oaborne-
Mendel
o rata/
Osborne-
Mendel
o rata/
Oaborne-
Mendel
o Hloe/
Oaborne-
Mendel
o Nice/
Oabornv-
Hendel
Doaa Duration Duration Purity
or of of of
Sax Bxpoaura Treatment Study Compound
M 530 a«/kg/day*>b 110 wa«ka 110 weeka ^99.91
M 210 a«/kg/day* 110 weeka 110 weeka > 99.91
H 0 ae/k8/dayb HA 110 weeka «»
( Mtohed-oontrol)
P " 610 a«/kg/dayr 110 weeka 110-111 weeka >99.9f
P - 350 •g/kg/dayr 110 weeka 110-111 weeka >99.9t
P 0 a«/kg/day HA 116-117 weeka HA
( amtohed-control)
M 830 a«/kg/day* 90 weeka 91 weeka > 99.91
H 720 B«/kg/daya 90 weeka 91-92 weeka >99.9f
Vehlole or
Phyaloai
State Target Organ
drinking nasal oavlty
water
drinking naaal cavity
water
drinking naaal eavlty
water
drinking naaal cavity
water
liver
drinking naaal oavlty
water
liver
drinking naaal oavlty
water
liver
drinking liver
water
1
drinking liver
water
Tuawr
Type
earolnoM0
earolnoew
oarolncNM
oarolnoaa°
adenoa*8
oarolnoaa
adenoM
oarolnoeia
adenoaa
oaralnoav
oarolnoaie or
adenoM
oarolnoaa
oarolnbva or
adenoaa
Tuanr
Inaldenoe
(P value)0
16/3*
(P40.001)
12/33*
0/33
8/35
(P'0.003)
11/32
(P<0.001)
10/35
(PiO.001)
10/33
(P<0.001)
0/3*
(P-0.008)
0/31
(P«0.001)
2»/»7
(P<0.001)
28/«7
(P<0.001)
18/50
(P<0.001)
19^50
(P.O.OH)
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Reference: NCI, 1978 (oont.)
Exposure Spec lea/
Route Strain Sex
o Bice/ H
Osborne-
Hendel
o Bloe/ P
Osborne-
Hendel
o Bloe/ P
Oaborne-
Nendel
o Mice/ P
Oaborna-
Hendel
Dose Duration
or or
Exposure Treatment
0 Bg/kg/day HA
( Batonad-oontrol)
860 Bg/kg/day r 90 weeka
380 Bg/kg/dayr 90 weeka
0 Bg/kg/day NA
( Batched-oontrol)
Duration Purity
or or
Study CoBpound
92-93 waeka >99.9*
90-91 weeka £99. 9*
91-92 waeka >99.9fl
91-92 weeka > 99.91
Vehicle or
Physical
State Target Organ
drinking liver
water
drinking liver
water
drinking liver
water
drinking liver
water
Tiaeor
Typa
oaroinoBB
earoinoBa or
adenoata
carolnoBa
carolnoBa or
adanoMa
oaroinoBB
oarolnoam or
adenoata
oarolnoaa
oarolnoaw or
adanoaB)
Tunr
Inoidanoa
(P value)"
2/«9
(P<0.001)
8/»9
(PiO.001)
29/3T
(P<0.001)
35/37
(P<0.001)
12/48
(P<0.001)
21/48
(P<0.001)
0/50
(P<0.001)
0/50
(P<0.001)
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Table A. Animal
kg«nt: 1, ^-UKoMrti*
Reference: MCI, 1978 (coot.)
Strengths of Studyi
weakness of Study:
•
Overall Adequacy:
Comments:
QUALITY QT BTIDCTCE
The compound was administered to two species of animals at multiple dose levels by a natural route of exposure.
The animals were exposed for a sign If leant portion of the llfeapan and comprehensive hlatologic examlnatlona
Mere performed. Survival In both speoles was affected by treatment, but sufficient numbers of rats and aloe
of both sexes were at rlak for development of late-appearing tumors.
The high-dose and matched control male rats were placed on the study 1 year after the study began. The total
doses received by the low and high doae groups do not reflect the two-fold difference In drinking water concentration
of the chemical (attributed to decreased pslatablllty wide Intake fluctuations)*' .
Adequate.
A significantly elevated Incidence of hemenglomes or hemanglosaroomaa at all sites was observed In the low-
dose female mice, but neither the dose-related trend nor the Incidence In the high-dose group wan significant.
The tumors were, therefore, considered to be unrelated to administration of the ohemloal.
* Average dally doae determined from the mean consumption of I.Of dloiane solution per week st Intervals during the second yesr.
b These groups were pieced on study t year after the study began, to replace two original groups of male rets that died during en
alr-oondltlonlng failure.
° Squamous-oell oarolnoma.
4 The probability levels for the Fischer Exact teat and the Coohran-Armltage teat are given beneath the Incidence of tumors In the
dosed groups and control groups, respectively.
* Since the low-dose group was started e year earlier without appropriate controls (Footnote b), the Incidence of tumors could not
be used for statistical analyses.
r Average dally dose determined from the mean consumption of 0.5$ dloxane solution per week at Intervale during the second year.
*
* Hepetooellular adenoma.
Hepetooellular carcinoma.
1 Hepatocelluler carcinoma or adenoma.
MA • Not Applicable.
-------
Teble lu AniKss.1
Agent: t(«.-Dloxan«
Reference: Torkalaon at al., 1971
Exposure
Route
1
1
1
1
Spec lea/
Strain Sex
rata/ K*
Ulster
rata/ M6
Vlatar
rats/ F*
Wlstar
rats/ Fb
Ulster
Dose
or
Exposure
O.H «g/l,°
7 hours/day x
5 days/week
0 ppm
O.ii .g/i,°
7 hour a /day x
5 days/Meek
0 ppm
Duration
of
Treatment
2 years
NA
2 yeara
NA
Duration
of
Study
2 yeara
2 yeara
2 yeara
2 yeara
Purity
of
Compound
>99.9«
NA
>99.9f
NA
Vehicle or
Physical
State Target Organ
vapor all altea
filtered all altea
air
vapor all altea
filtered all altea
air
Tumor
Type
total tumor a
total tumors
total tumors
total tumors
Tumor
Incidence*
(P value)
3»/150*
57/206*
67/139*
101/217*
Strengths of Study:
Weakness of Study:
Overall Adequacy:
CcMBBenta:
QUALin OP EVIDENCE
The ooaipound waa adailnlatered by a natural route of exposure at a low level of exposure for a significant portion
of the llfeapan. Comprehensive hlstopathologlo examinations Mere perforated on a large number of animals.
A single exposure level was tested.
Adequate.
This atudy vas particularly well designed and reported.
* 268 rats/sex In 3 replicate groups (96/aex/group).
b 192 rats/sex In 3 replicate groups (96/aex/group).
0 111 pp».
d 50» of the anlMla survived 20-24 •onths.
* Coeprehenslve gross and •lorosooplo exaalnatlons of the aajor organs and tissues revealed no treatawnt-related lesions. A detailed
•orphologic classification of all tuawra that occurred In rata that survived at least 9 Months uas published; the total nuafcer of
tuawra observed at all altea In treated and control rata was tabulated and Included here.
NA • Not Applicable
-------
APPENDIX B
-------
5^^
PB 285 711
National Cancer Institute
CARCINOGENESIS
Technical Report Series
NO. 80
1978
BSQASSAY OF
1,4-DIOXANE
FOR POSSIBLE CARCINOGENICITY
CAS No. 123-91-1
NCI-CG-TR-80
U.S. DEPARTMENT OF HEALTH. EDUCATION, AND WELFARE
Public Health Service
National Institutes of Health
«mn»ucio IT
NATIONAL TECHNICAL
INFORMATION SERVICE
ILS.O(PA»TMCNT Or C
JMINCIIOJ). V*.
-------
BIOASSAY CF
1,4-DIOXANE
FOR POSSIBLE CARCIii
-------
BIO/. S SAY Of
1.4-UIC2ANE
FOR POSSIBLE CARCINOGENICITY
Carcinog*nesis Testing Program
Divlsior of Cancer Cause and Prevention
tUtitrcal Cancer Institute
National Institutes of Health
FOREWORD; This report rresents the results of the bioass*y of
l,
-------
Willigan*, who also prepared chc Interpretive pathology summary
Included in this raport.
Animal pathology tables and survival cables were compiled at ECciC
Mason Re»«ar:h Institute5. The ttatiutical analyses were
performed by Dr. J. R. Joiner6 and M*. ?. L. Yong6, using Methods
•elected for the bioasaay program by Or. J. J. Care7. Chemicals
used in this bioassay were analyzed under the direction of Or. A.
Cray3, with tha assistance of S. Cepa3 and V. Da/>iuto3. Further
analyses were conducted under the direction of IT. E. Murrill8.
Th« results of the analytical work were reviewed by Or. S. S.
Olio*. The structural formula for the chemical uas provided by
NCI.
This -eport was prepared at Tracer Jitco6 under the direction of
Or. Marshall Steinberg, Director of the Bioassay Program; Dr. L.
A. Campbell, Deputy Director for Scler.ce; Drs. J. e. Robens and
C. U. Williams, toxicologl&ts; Dr. C. L. Miller, Ms. L. A. Uaitz,
and Mr. U. D. Reichardt, bioscience writers; and Dr. E. W.
Junberg, technical editor, assisted by Ms. Y. E. Presley and
Ms. P. J. Graboske.
The statistical analysis was reviewed by members of the
Mathematical Statistics and Applied Mathematics Section of NCI7:
Dr. John J. Cart, Mr. Jun-mo Nam, Or. Hugh M. ?ettigvc«--, and Dr.
Robert E. Tarone.
T'.ie following other scientists at NCI were responsible Cor
evaluating the bioassay experiment, interpreting chc results, and
reporting the findings: Dr. Kenneth C. Chu, Dr. Cipriano Cueto,
Jr., Or. J. Fielding Douglas, Dr. Dawn C. Goodman, Tr. Richard A.
Criesemer, Dr. Harry A. Miitaan, Dr. Thomas U. Orae, Dr. Robcri. A.
Squire', Dr. Jerrold M. Ward.
IV
-------
^arclnogenesis Testing Program, Division of Cancer Cause and
Prevention, National Cancer Institute, National Institutes of
Health, Bethesda, Maryland.
2Now with the Office of the Commissioner, Food and Drug
Administration, Rockville, Maryland.
3IIT Research Institute, 10 Wost 35th Street, Chicago. Illinoi..
*Dcaal«l A. Wllligan, Inc.. Research' Patholcgy Offices, 309 East
Second Street, Bound Brook, New Jersey.
Mason Ret earch Institute, 1530 ?aat Jefferson Street,
Rockville,
^Tracer 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, Buthesda, Maryland.
8Midwest Research Institute, 425 Volker Boulevard, Kansas City,
Missouri.
?Now with the Division of Comparative Medicine, Johns Hopkins
University, School of Medicine, Trayloc Building, Baltimore,
Maryland.
-------
SUMMARY
A bicassay of 1,4-dioxane for possible carclnogeniclcy was
conducted by adminiatering the test chemical in the drinking
to Oaborne-Mendei rats and B6C3FI mice.
Croups of 35 rats and SO mica of each sax ware administered
1,4-aioxane at concentrations of either O.JZ or l.OX (v/v) in the
drinking water. Because of variations in intake of wacer, the
doses of test chemical received by the high-dose groups were not
precisely twice those received by the low-dose groups; in the
•ale mice, the high dose was only slightly greater than the low
dose. The rats were dosed for 110 weeks and the mice for 90
weeks. Matched controls consisted of 35 untreated rats and 50
untreated mice of each sex. All surviving rats were killed at
110-117 weeks and all surviving nice at 90-93 weeks.
Th« mean body weights of the rats and mice were not conaistently
affected by the administration of dloxana. Survival ratts of the
dosed groups of rats and female mica were lower than thoae of
corresponding control groups, but sufficient numbers of animals
were at risk for development of late-appearing tucors.
In rats, the incidence of aquamous-cell carcinomas of the nasal
turbinates waa statistically signlf icat c in r.eats for dose-
related tread in females (P • 0.008) and tor direct comparison of
high-dose with matched-control males (P < 0.001) and direct
comparison of dosed with control females (P £ 0.003) (males:
controls 0/33, low-dose 12/33, high-dose 16/34; females:
controls 0/34, low-dose 10/35, high-dos* 8/35). In the females,
but not in the males, th« Incidence 'f hepatocellular adenomas
was significant (P £ 0.001) in tests ft-r dose-related trend and
for direct comparison of both low- anu high-dose groups with
controls (controls 0/31, low-dose 10/33, hi&h-dore 11/32).
In both male and fenale mice, the incidence of hepatccellular
carcinomas was statistically significant (P <. 0.001), boch in
tests for dose-rriated trend and dl_rect comparison of boch dosed
groups with controls (mal-is: control? 2/49, low~io!»e 13/50, high-
Prcceding page blank
vii
-------
dose 24/47; females: controls 0/50, low-done 12/48, high-dose
29/37). The incidences reaaioed significant when hepatocelJular
adenomas weu combined with hepatocellular carcinomas.
It is concluded that under rh<> conditions of this bioassay,
)t4-dioxane induced hepatoceilular adenomas in female Osborne-
Mendel rats. 1,4-Qioxane was carcinogenic in both sexes of rats,
producing squamous-cell carcinomas of the naiu.l turbinates, and
in both sexes of B6C3F1 mice, producing hepatoc-lluiar
carcinomas.
viii
-------
TABLE OF CONTENTS
Page
1. Introduction i
II. Materials and Ketl'ods 3
A. Checiical 3
B. Dotage Preparation 4
C. Animals 4
D. An.uul Maintenance , 4
E. Designs of Chronic Studies 5
F. Cliniial and Pathologic Examinations >.. 6
G. Data Recording and Statistical Analyses 9
III. tesults - Rats 15
A. Body Weight* and Clinical Signs (Rats) 13
B. Survival (Rats) IS
C. Pathology (Rats) 13
D. Statistical Analyses of Results (Rats) 21
IV. Results - Mice 25
A. Body Weights end Clinical Signs (hU.ce) 25
B. Survival (Mice) 25
C. Pathology (rllci> 18
0. Statistical Analyses of Results (Mice) 30
V. Discussion 33
VI. Bibliography 37
APPENDIXES
Appendix A Summary of the Incidence of Neoplasms
in Rats Administered 1,4-Dioxane in
the Drinking Water 39
Table Al Summary of the Incidence of Neoplasms
in M^le Rats Adninistered 1,4-Dioxane
in the Drinkir.s Water 41
IX
-------
Fane
Table A2 Summary of the Incidence of Neoplasms
in Female Rats Administered 1,4-Oioxane
in the Drinking Water 45
Appendix B Summary of the Incidence of Neoplasms
in Mic* Administered 1,4-Oioxane in
the Drinking Water 4"
Table Bl Summary of the Incidence o£ Neoplasm*
in Male Mice Administered 1,4-Oioxane
la the Drinking Water 51
Table B2 Summary of the Incidence of Neoplasms
in Female Mice Administered 1,4-Oioxane
in the Drinking Water 55
Appendix C Summary of the Incidence of Nonneoplastir
Lesions in Rats Administered 1,4-Oioxane
in the Drinking Water 59
Table Cl Sumcary of the Incidence of Nocneoplastic
Lesions in Male Rats Administered
1,4-Oioxane in the Drinking Water 61
Table C2 Summary of the Incidence of Norcsoplastic
Lesions in Female Raid Administered
1,4-Oioxane in the Drinking Water..... 66
Appendix D Summary Gi the Incidence of Nonneoplastic
Lesions in Mice Administered
1,4-Di^xane in the Drinking Water 73
Table Dl Sunmary of rhe Incidence of Nonneoplastic
Lesions in Male Mice Administered
1,4-Oioxane in the Drinking Water 75
Table 02 Summary of the Incidence of Nonneeplastic
Lesions in Female Mice Administered
1,4-Oioxane in tne Drinking Water 76
Appendix E Analyses of the IncJJenre of Primary
Tumors in Rats Administered
1,4-Oioxane >.n cue I) rink lug U«<-er SI
-------
Pag*
table El
Table E2
Appendix F
Table Fl
Table *2
Table 1
Table 2
Figure 1
Figure 2
Fig-ire 3
Figure 4
Analyse* of. che Incidence of Primary
Tuaora in Hale Rat a Administered
1,4-Oioxane in Chi Drinking Water 35
Analyaea of che Incidence of Primary
Tuaora in Female Raca Admlniacered
l,4-0iox«ne in che Drinking UaCor 92
Analyaea of che Incidence of Primary
Tuaora in Mice Administered
1,4-Dioxane in Che Drinking Water 97
Analyaea of che Incidence of Primary
Tuaora in Male Mice Administered
1,4-Dioxane in che Drinking Uacer 99
Analyses of che In:idence of Priaary
Tumors in Female Mice Administered
1,4-Dioxane in che Drinking Water 103
TABLES
Desigu of Chronic Studies of
1,4-Oioxane in Rats 7
Design of Chronic Studies of
1,4-Dioxane in Mice 8
FIGURES
Growth Curves for Rats Administered
1,4-Dioxane in the Drinking Water 16
Survival Curves for Rats Administered
1,4-Dioxane in the Drinking Water 17
Growth Curves for Mice Administered
1,4-Dioxane in the Drinking Water 26
Survival Curves for Mice Administered
1,4-Dioxane in the Drinking Water 27
xi
-------
I. INTRODUCTION
1. 4-OIOXANE
1,4-Dioxaue (CAS 123-91-1; NCI C03689), a diner of ethylene
oxu.dc, hereinafter called dioxane. Is used extensively =* an
incustrial solvent for lacquers, varnishes, paints, plastics,
dyes, oils, waxes, resins, and cellulose acetate and as an
inhibitor in chlorinated solvents (Stecher, 1968; Stantord
Research Institute, 197S; Hath^son, 1972). In biological and
chemical laboratories, dioxane is employed as a solvent for
tissue processing, liquid scintillation counting, and
photochemical reactions. Nearly 18 million pounds were produced
for these uses in 1975 (U. S. Incernational Trade Commission,
1976).
The citcitiog-jnicity or dioxane has been studied extensively.
(Argus et al., J965; Uoch-Ligeti et al. , 1970; Argus ec .il. ,
1973; Kociba et al., 197C). Dioxane was selected for testing
along wich a series of chlorinated dibenzo-p-dioxins, some of
which are highly toxic contaminant.;* ol certain herbicides and
[/entachlorophenol microbicidas.
1
-------
II. MATERIALS AND METHODS
A. Chemical
The chemical tested was reagent-grade dloxane supplied by J. T.
Baiter Chemical Co., Phillipsburg, New Jersey. Lot* No. 43468 and
43475 were used during cite chronic studies and were analyzed Co
confirm chelr Identity and purity. The analysis of Lot No. 43475
was performed several months after completion of the bloaaaay.
Vapor phase chromatography showed Lot No. 45468 to be ac least
99.9Z dloxane. Spectra were consistent with the structure of
dloxane. Both lots were also analyzed by polaro%raphy for tM
presence of sodium dlethyldlthiocarbamate, an Inhibitor of
peroxide formation, stated by the manufacturer to be present at a
level of 0.001Z. Lot No. 43475 could not be analyzed for the
inhibitor because of an interfering substance. in Lot No. 45468,
less than 0.00022 sodium diethyldithiocarbamate was detected.
The presence of peroxide was measured by deration with titanium
tatrachloride or sodium iodide. Lot No. 45468 had very low
levels of peroxide, less than 0.001Z peroxide, while Lot No.
43475, in contrast, had a level of 0.109* peroxide (calculated as
dloxane hydroperoxide). Argus et al. (1973) analyzed their 10Z
dioxane stock, solutions and tap water dilutions used in a dosed
walsr study for peroxides, but could detect none (< 0.0002Z).
Preceding page blank
-------
8. Dosage Preparation
The dloxan* soIULion* for cliis study were prepared in cap wacer
twlc« p«r week and scored In poiyechylene concalaers. These were
Chen used Co supply che wacer beetles for the doced animals.
C. Animals
Osborne-Mendel rats and B6C3F1 mice of both sex.it were used la
the chronic ntudles. All aaimals were obcained from Charles
River Breeding Laboratories, Inc., Wilmington, Massacnubeccs,
under a contract wich che Division of Oncer Treatment, NCI.
Rats and mice were .received at C'.JB test laboratory at approxi-
mately 4 weeks of age. They were quarantined for I week.
Animals having no visible signs of disease "ore then earmarked
an4 assigned co control cr do*ed groups according to a series of
random numbers.
0. Anim.il Maintenance
A"loals were housed in ..emperature- and humidity-controlled
rooms. The temperature was maintained at 22-23°C and tht
relative humidicy ac 40-502. Fluorescent lighting vas provided
for 12 hours each day. Room air was changed 22 times par hour
and exchanged through fiberglass filt^ru.
Rats were housed 4 per cage and n.ice 10 per cage in suspended
-------
polypropylene cagtn (Maryland Plastics, Federalsburg, Maryland),
covered with a wire mesh scieen and a polyester filter. A wo«d-
chip bedding (Abaorb-Ori*1, Lab Products, Carfi^d, N. J.) was
used in th« cages. Dos#d water or cap water in glass water
bottle* with sipper tubes was available to respective groups of
animals ad libitum; bottles were refilled twice per week.
/nimals were fed Wayne® Lib Bio- animal meal (Allied Mills, Inc.,
Chicago, Illinois). Diets were available ajd libitum and were
supplied once per week..
Cages, cage lid?, and water bo teles, were sanitized at 82°C once
per week. Bedding was replaced once per week. Rats and nice
were housed in separate rooms. Untreated controls wers housed in
the same room with the dosed animals. Rats and oi<- • dosed with
dioxane were housed in the same room with rats and mice fed
dibenzodioxin (CAS 262-12-4), 2,7-dichlorodibenzodioxin (CAS
33357-26-0), and 1,2,3,4,b, 7,8,^-octai.hlorodibenzodioxin (CAS
3268-87-9).
E. Designs of Chronic Studies
In this study, dioxane was administered to rats ind mice at
concentrations of either 0.5% or L.OX in driukjng water. These
concentrations were chosen on the basis of doses administered in
previous studies (Argus et al., 1965). During the second year of
the study, fluid int.ike was measured for i w«ok out of every
5
-------
month. This permitted an estimation c£ the average daily dioxane
intake, bhown in tables 1 and 2. Decreased fluid consumption was
observed in the high-dose male mice. In which, the average daily
intake of the test chemical was only slightly higher than that of
the low-dose group and did not reflect the twofold difference in
concentration between the -ow and high doses.
F. Clinical and Pathologic Examinations
Animals were observed twice daily. Body weights were measured
every 2 weeks for tht first 12 weeks and ovary month during the
resc of the sr.udy. Measurement of food and water consumption was
begun during the second year of the study, and was dene once per
month using 2QX. of the animals of each group as a representative
sample of the population.
Animals that were ooribund were killed. All animals were r.scrop-
sied whether they died or were killed, except for tt.ose lose
through cannibalization or aucolysis. Tie following tissues were
taken at necropsy: oamaary gland, trachea, lungs and bronchi,
heart, bone marrow, liver, gall bladder (mice) and bile duct,
spleen, pancreas, kidney, esophagus-, thyroid, adrenal, gonads.
brain, sruoach, nasal seotum, fWin, and tissue masses. Ac 105
w
-------
Table 1. Design of Chronic Studies of 1,4-bloxane in Rat*
Sox .ind
Test
Croup
Halo
Matched-Concrolc
Low-l'ose
High-Dose0
ilatclicd-Controld
Luu-DobC
High-Dose
aAll animals were 5
Initial
No. ol
Animals*
35
35
35
35
35
35
weeks of age
DThe mean consumption of dlokane
I he bccond yjar of
following formula:
o)R/*K/day • mean ml
the bloassay
1,4-Oloxanc
in Drinking
Average
Dose
Water (X.v.'v) (»R/kR/diy)b
0
0.5
1.0
0
0.5
1.0
0
240(130-3£C)
530(790-780)
0
350(200-580)
640(500-940)
Time
Dotted
(weeks )
110
110
110
110
110
110
on Study
Observed
(weeks)
0
0
0
6-7
0-1
0-1
when placed on study.
solution per week was determined at
. The average
i;olutior. consumed /wk x X
doses were calculated
intervals during
with the
'loxane x density of dloxane x
use of tli«
10
mean kg body'weight x 7
clhese groups, were placed on study 1 year after the study began, to replaca two original
groups of ou.le rats that died during an air-conditioning failure.
ed f.-malc controls were placed on study 5 weeks later than the dosed groups.
j
-------
Table 2. Design of Chronic Studies of 1,4-tiioxane in Mice
Sex and
Test
Group
Ma!-:
Matched-Control
Lou -Dose
High-Done
r _-male
oo Matched-Control
Low-Dose
Illfch-Uose
aMicc wore 3 weeks
Initial
No. of
Animals3
50
50
50
50
50
50
1,4-Uloxane
in Drinking
Water (Z,v/v)
0
0.5
1.0
0
0.5
1.0
Average
Dose
(n>g/kg/day)b
0
720(330-<*90)
830(680-1150)
0
380(180-620)
860(450-1560)
Tine
Dosed
(weeks )
90
90
90
90
90
90
on Studyc
Observed
(wcekti)
2-3
1-2
1
1-2
1-2
0-1
of age when placed on study.
kflic nioa.. consumption ot Ulxxane solution per week was determined at intervals during
the second year of (he bloas^iy. The avor.igu doses were calculated with the use of the
tol lowing formula:
m^/k^/day » mean m1 solution consumed /wk. x Z dloxanc x density of dloxane x 10
mean kg body weight x 7
cCroupa were placed on study not n.ore thin 7 weeks apart.
-------
groups of rats which were started a year later than th« original
group, of rats and mJc«. n,. tissues taken after that tin*
included skin, mandibular lyiLph node, salivary glaw!, mammary
gland, bone marrow, thymu*. larynx, trachea, lungs ar.d bronchi,
heart, thyroid, parathyroid, esophagus, stonach, duoc^nua, colon,
••senteric lymph node, liver, pancreas, spleen, kidney, urinary
bladder, adrenal, gouada, nasal cavity, brain, pic-jidry, spinal
cord, skeletal muscle, tciatic nerv-, and tissue, trusses. Tlsscss
w»r« preserved in 10Z buffered foraalin, embedded in paraffin,
sectioned, and stained vith henatoxylia and eosin. All :issue*
were examined microscopically by the pathologist.
A few tissues from some animals were uot cxa«iined, particularly
from those animals that aied early. Also, some animals were
missing, cannibalized, or judged to be in such an advanced scati
of autolysis as to preclude histovathologic evaluation. Thus,
the nu&ber of animals from which particular organs or tissues
we fa examined microscopically varies, and docj not necessarily
represent the nuab«r of animals that were placed on study in each
group.
C. Data Recorder-; and Statistical Analyses
Pertinent data on chis experiment have been recorded in an auto-
matic iata processing system, che Carcinogenesls Bioass»ay Data
-------
System (Llnhart et al., 1974). The data elements ir.-i.de descrip-
tiv« information on the chemicals, animals, experimental design,
clinical observations, survival, body weight, and individual
pathologic results, as recommended by the International Union
Against Cancer (Berenblua, 1969). Oata tables were generated for
verification of data transcription and for statistical review.
These data were analyzed using -he statirtical techniques
described in this section. Those analyses of the experimental
results th&t b«ar ca 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; aniaals 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 nd Tarone's (1975)
extensions of Cox's methods for testing for a dosa-r: '.aced trend.
One-tailed P values have been reported for all tests except the
departure from linearity test, which is c.iiy reported when its
two-tailed P value is less than 0.05.
10
-------
The incidanc* of neoplastic or nonneoplastic lesions ha.i been
givaa as the ratio of the number of animals bearing such lesions
•t a specific anatomic sice (numerator) to the number of animals
In vhich that *ite is examined (denominator). In most instances,
th« denominators included only those animals for which that site
va* examined hlstologlcally. However, when macroscopic examin-
ation was required to detect lesioos prior to histologlc sampling
(e.g., skin or mammary tumors), or when lesions could have
appeared at multiple sites (e.g., lymphomaM), the denominators
consist of the numbers of anisals 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
ar.i-als. Aa 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 i group of dosed animals at each
dose level. When results for a number of dosed 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 Bonferroai inequality (Millar, 1966) requires thac the
P -'alue for any comparison be less chnn or equal to 0.05/k.. In
cases where this correction was used, it is discussed in t',,e
11
-------
.narrative section. It is noc, however, presented in rhe cables,
wh«r« Che Ftsher exact P values are shown.
Th« Cochran-Armitage cesc for linear trend in proporcions, with
continuity correction (Armitage, 1971), was also used. Under the
assumption of a linear trend, this test determine* if the slop*
of the dose-response curve is different frota zero at the one-
tailed 0.05 level of significance. Unless otherwise noted, the
direction of the significant trend is a positive dose relation-
ship. This method also provides a two-tailed test of departure
fro* linear trend.
A tine-adjusted analysis was applied when numerous early deaths
resulted froa causes that were not associated with the formation
of tumors. In this analysis, deaths that occurred before Che
first tumor was observed were txcl'ided by basing th* statistic*!
tests on animals that survived at least 52 week*, unless a tumor
was found at the anatomic site of interest befor ± week 52. When
such an early tumoi: was found, comparisons were based exclusively
on animals cKac survived at lease as long as the animal in which
the first tumor was found. Once this reduced sec of data was
obtained, the standard procedures for analyses of th«- incidence
of tumors (Fisher exact tests, Corhran-Arnitage tests, etc.) were
followed.
-------
Wh«n appropriate, life-table methods were used to analyze the
incidence of tumors. Curves of the proportions surviving without
an observed tumor were compute* a* in Saffiotti et al. (1972).
The week during which .-in animal died naturally or was sacrificed
was entered as the tlfcj point of tumor observation. Cox's
••chads of comparing these curves were used for fjo groups;
Tyrone's extension to testing for linear trcud was used for three
groups. The statistical tests for the incidence of tumors which
used life-table rethodf were one-tailed and, unless otherwise
noted, in the direction of a positive dose relationship. Signifi-
cant departures from linearity (P < 0.05, two-tailed tr.at) were
also noted.
The approximate 95 percent confidence interval for the relative
risk ot each dosed group compared with its control was calculated
from '.he exact interval on the cdds ratio (Cart, 1971). Tht
relative risk Is defined as pc/pc where pc is the true binomial
probability of the incidence of * specific type of tumor in a
dosed group of animals and pc is Che true probabi." icy of die
spontaneous incidence of the same type of tucor In a control
group. The hypothesis of equality between the true proportion ->t
a specific ticaor in a dosod group and che proportion in a control
group corresponds co a relative risk of unity. Values in excess
13
-------
of unity represent the condition of t larger proportion in the
dosed group th*n in the control.
The lover and upper limits of the confidence interval of the
relative risk have been included in the tables of statistical
analyses. The interpretation at the Units is that in approxi-
mately 9SZ of a larg* number of identical experiments, the true
ratio of tha risk in a dosed group of animals to that In a
control group wruld be within the interval calculated from the
experiment. When tha lower limit of the ccofidecce interval is
greater than one, it can bi inferred that a htatistlrally signifi-
cant result (P < 0.025 one-tailed test when the control incidence
is not zero, P < O.OSO when the control incidence is zero) has
occurred. When the lower licit 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 theoretic*! possibility of the induction of
turners by the test cheaical, which could r.ot be detected under
the conditions of this test.
14
-------
III. RESULTS - RATj
A. Body Weights and Clinical Signs (Rar*)
Mean body weights of che low-dove males were higher Chan chose of
Che oacched coatrols. particularly during the second year of the
bioasaay, while those of the low-dose females were comparable
throughout the test period Cigure 1). The weights at the high-
dose animals of both sexes were lower than those of the controls,
particularly during the second year of the bioassay. Fluctuation
in the grrvth curve nay be due to mortality; as th« size of a
group diminishes, the mean body weight may b« subject to
variation. No clinical signs other than those of altered body
weights were reported.
B. Survival (Rats)
The Kaplan and Meier curves estimating che probabilities of
survival for male and icmale rats administered dioxane in che
drinking water at the doses of this bin^ssay, together jith those
of the matched controls, are shown in figure 2.
In each sex, the Tarone test result for positive dose—related
trend in mortality is significant (V < 0.001). Departures fron
linear trend ?re observed (P - 0.010 \n males, P - 0.030 ir.
fenales), due to the relatively sLecp decrease in survival
15
-------
2 ^
O
e
"•il
0
a
83
o
a Q
o
S
a a
00
o
a
MALC «AT»
O •*rex
O IOBO
(WItMMMM •
TIM! ONSTUO. IWtiKSI
I «•
o
2 >••
<
w
9 a
!§a
o 9
e
A
FCMALt RATS
O KtioxacoiiTo
O too 0011
40 M MJ '0 M
TIMI ON STUDY IWEEtSI
Figurt 1. Grow* Curve* For RaB Adir:nijteren l,4-0:oxant in thi Drinking Wittr
16
-------
* tt m •+
TIMI ON rruov IWIEKSI
ta
»
O
H
Ff MALI HA' S
Q M*TCMfOCeM'*OI.
A--J-,
4 o—
*- —
,0 ra ao
TIMI ON STUDY IWIEKS'
Figure 2. Survrvil Curves for Rats Adminrstarad 1,4-Oioxana in the Drinking Watar
17
-------
observed In the dos«d group*. In male racs, 33/35 (942) of the
higu-doae group, 26/35 (742) of Che low-dose group, and 33/35
(94Z) of the natchfcd control* lived ac lease as long as 52 weeks
on study. la femaJe racs, 29/35 (832) oi the high-dose group,
30/35 (86Z) of chc low-dose group, and all 35 of the OMtched
controls lived beyond week 52. sufficient number* of rats of
each sex were at risk fot development of tumors appearing within
tnis period.
C. Pathology (Rats)
Histopathologic findings on neoplasms in rats are summarized in
Appeioix A, tables Al and A2; findings on nonneoplastic lesions
are summarized in Appendix C, tables Cl and C2.
Necplasoa associated with administration of dioxane occurred in
the nasal cavity (squamous-cell carcinomas, adcr.ocarcinooas, and
rhabdooyomas) in each sex, liver (hcpaf-cellular adenomas) in
females, anc* tesrts/epididymis (mesoche1iomas) in males.
The Incidence of tumors of ;he nascl cavity was relacei' co Che
dioxane to which the rats were exposed. S^uaraous-cell carcinomas
occurred in 12/33 (362) low-dose sales, 16/34 (472) i.igh-doso
males, 10/35 (29X) low-dose females, and 8/35 (23%) hi^a-dose
females. The first tumors were observed at week. 52 in males and
18
-------
at week 66 in females. None were found In che 33 male controls
and 34 female controls.
Nasal squamous-cell carcinomas varied morphologically from
minimal foci of locally invasive squamous-cell proliferation to
advanced growth consisting of extensive columns of epithelial
calls projecting either into free spaces of the casal cavity
and/or infiltrating the suboucosa. Although reasonably well
differentiated (fomaciun of cell nests and certification), local
Invasivenes* was comnon and extended to the retrobulbar tissues
of the ey« in 1/10 high-dose rales, and to the brain in 1/12 low-
dose males. Distant metastasis to the lung occurred in 1/8 high-
dose females. Adenocarcinomas (aonkeratinizing) arose from na&al
oucosal epithelium in 3/34 (9Z) high-dose males, 1/35 (21)
low-dos*, and 1/35 (32) high-dose females. They extended
primarily into the free space of the nasal cavity. The neoplasms
were reasonably well differentiated, with varying infiltrations
into the suboucosal tissue. Metastasis to the lung occurred in
1/3 high-dose males having these tumors. The single instance of
a benign skeletal ousclc Cumor (rhabdooyooa) was observed in 1/33
(32) low-dose males.
Although hepatocellular hyperplasia (cytonegaly) occurred in both
dosed and control groups, hepatoceliular adenomas were primarily
seen in livers of female rats (0/31 [02] controls, 10/33 [302]
19
-------
low-dose, u/32 [342J hlgh-dos«). These neoplastic foci
consisted of proliferating hepatic cells oriented as concentric
cords. Ih« foci were sharply delineated froo immediate normal
parenchyma which yielded to coapression. Hepatic cell size was
variable; mitoses and necrosis w«re rare.
tlesoth^llomas involving the vaginal tunic* of the testis/
epididyais were apparent in dosed animals oor« frequently than in
the control group (2/33 I6Z] high-done controls, 4/33 [122]
low-dose, and 5/3* [13ZJ high-dose). Microscopically, these
growths w«re characterized at rounded and papllliry projections
of mesothelial cells, each supported by a core of fibrous tissue.
Although other benign and malignant neoplasms occurred in various
tissues, each type h&s been encoun:ered previously as a spontan-
eous lesion in the rat* Moreover, the incidences of neopla*os
are not related to administration of the cest chenical by type,
site, test group, or sex.
Nonn»oplastlc responses associated wich exposure Co dioxane were
observed in the kidney (tuouldr degeneration;, liver
(cytomesaly)t and brooach (ulceracion). Renal changes were
characterized wichin c!ie proximal cortical tubular epithelium by
marked vacuolar degeneration and/or focal tubular epithelial
regeneration. Hyaline casts were seen on occasion. Gastric
20
-------
ulceratlon of the stomach was observed In 5/28 (182) low-dose,
5/30 (17Z) high-dose, acd no control males. Females were
affected negligibly.
Ooeed rats had higher incidences of pneumonia than the controls
(8/30 [27Z] controls, 15/31 [483:] low-dose, and 14/33 [42Z] high-
dose nales; 6/30 [20ZJ control, 5/34 [15XJ low-dose, and 25/32
[78ZJ high-dose females), and the development of nasal carcinomas
may have beea a contributing factor.
A variety of other nonneoplastic lesions were represented among
both control and dos<4d animals. Such lesions have been
encountered previ-A-sly and are considered spontaneous events not
unlike those commonly observed in aging rats.
Based on the histopathologic examination, dioxane was
carcinogenic, producing squauous-cell carcinomas of th
-------
the Ml* rats consist only of Fisher exact tests, comparing
incidences in the high-dose with those in the control groups.
These groups were tested concurrently; the low-dose group,
however, va» started a year earlier without appropriate controls.
Although the incidences of tumor* in the low-dose group of male
rats were not used for statistical analysis, they are jhovn in
cable El.
Squacous-cell carclnoaas of the nasal turbinate occurred in a
significantly (P < 0.001) higher projjcrtion In the high-dose
group of male rats than in the control £roup. Whllr no tests
were Bade using the proportion of 12/33 (36Z) seen in the low-
dose group, thl£ proportion approaches the 16/34 (47Z) seen in
the high-dose group. In females, the Cocnran-Armitage test is
significant (? - 0.008). An indicated departure from linear
trend is observed (P • 0.039), because the proportion- in the
low-dose group Is slightly greater than that in the high-dose
group. The Fi&her exact test shows that the incidences in both
the dosed groups are signif ic. ntly higher (P _< 0.003) than th..t
in the matched controls. The statistical conclusion Is that this
tumor in both sexes of rats is associated wich the adninistration
of the test chemical.
In female rats, the Cochran-Armitage test result for the
incidence of hepatocellular adenomas is significant
-------
and the Fishsr exact test shows that the Incidences in both che
low- and high-dose groups are significantly higher (P <, 0.001)
than that in the matched controls. The statistical conclusion is
that the incidence of this tuaor in the female rats is associated
with ad.iiniatration of the test chealcal. The statistical test
results en the incidence* of this tuner in Okie rats are not
significant.
SignificabC results in the negative direction are observed in the
incidence of C-cell adenomas in female rats.
The statistical conclusion is that the incidence of squarous-cell
carcinomas of the nasal turbinate in both sexes of rats and the
incidence of hepatocellular adenomas in female rats are
associated with the administration of dioxane.
23
-------
IV, RESULTS - MICE
*• Body Wei«ht« «nd Clini^j st«na (Mice)
ttaaa body v*ighcs of Ml* ale* ac th« low-do** wete comparable co
those of ch* matched concrols. wall* ac ch* hlgh-do*«. eb« mean
s - -. *. -
body Msighc* were allghcly elevated (figure 3). Itaaa body
of low-do** f*a*l* ale* w«r* hi«b*r Chan eto*« orf ch*
r - -> i ?'-l* *< .
eoacrol*, and body weight* of ch* nl^h-doa* anlaal* v-»r* low*r.
FlueCuacioa in ch* grovcU eurv* a*y b* du* co aorcallcy; as ch*
•iz* of a croup dlBlnish**, th» a*an body w*lghc a*y b« «ubj*et
Co variation. No clitical •iftn« och*r than cho** of alc*r*d body ,
w*ighca «Mt* reported.
3. Survival (Mice)
The Kaplan and Mater curve* vsciaacing Che probabilicie* of
survival for aal* and feaale aice administered dioxane in the
drinking water ac the dose* of this bioassay, together with :hose
of the matched controls, are shown in tlgure 4.
In asle aice, the Tarona test result for positive dose-rela :cd
trend in mortality is noc significant, with at least 90Z of the
aniapi* la each group (45/50 [90Z] in the high-dose group, 46/50
[92Z] in Ch* low-dose group, and 48/50 I96t] in ihe control
group) scill alive ac week 91. In females, the Tarone test
Preceding page blank
25
-------
»
A A
A A A
A A A
9°'8 5°
a so
o
a
B
O A
e
<• M • <•
TIMI on rruor IWUMI
I ,.
OOA no
00 _ o o o 8
a a
Q n
O I.
lOt II-
TIMI ON STUOT IWIIRSI
Ftjurt 3. Growth Cuivw For Met Adminutetd 1,4-Owiufli in tfit Oinung Wittr
26
-------
TMM ON rroor iwnrai
5
3
*•
KMAU MICI
O
A
I I
TIMI ON truer nwimsi
for Mia Mautvund 1,4-Okjxww in tilt 0ricking W«ar
27
-------
1» •igaificut (P < 0.001). with 28/50 (561) of tha
hfgfc-doce gr.-up, 39/50 (78Z) of the lov-do*e group, and 45/50
<*OX) of the matched control* still alive at week 91. Sufficient
nuabars of mice of each sax v
-------
ouslsi. Despite extensive proliferation, cha Inter-
lacing cords of hepatic calls seldoa revealed mitosis. Although
locally iuvssivs vlthia the live:, astastavls cu 'h« lung v»s
rarely observed (1/50 [22] low-done Mies).
infllcrscloa wss not extensive. Nasal eucosal polyps ««r« ram
(IAS (2Z1 low-4os« resales and 1/49 (?Z1 his>-dose Miss). Tks>
polyps were derived froa aucus-secreelnt epitheliua and wars sot;
otherwise rewritable.
A variety of other beoign and ssiigaant neoplasms occurred;
however, each type has been encountered prsvlimsly a* a apontan-
euus lesion in the 86CJFI mouss. It is apparent that th«
incidences oC thosa nooplasos arc unrelated by type, tits, group,
or sex oC animal, and hence, are uaattrlbutable to exposure to
th* chciaica).
01 tho nonneeplastic lesions rsprrsented aaong both control aad
drsed anlasl«i the increasad inciionce of pneu-wnia
. 3^^*"' - &
tlon)
and chinitia (acute intlaoaation, acute
tlv* Inflamoation)'waa significant. Pneumonia occurred in
29
-------
.!>
1/49 (2Z) control, 9/30 (18Z) low-dose, aad 17/47 (36Z) hl^h-cose
aales; 2/50 (4Z) coacro , 33/47 (70Z) low-dose, aad 32/36 (S9Z)
higfc-aoee feaeles. &*a±ti* wa« eosarved ia 1/30 (2Z) lo»-do«e.
obc«rv«d la afiatt ale*.
I -
I
y
Based oa the histopathologic exaaiaaclon,
carcinogenic, producing hepatocellular
feaale B6CJF1 iuic* exposed to the eheileal la drlaklag
0. Statisticfl Arnlvses of Results (Mica)
Tablea F3 and F4 la Appendix F coatala the scatlarical aaalysea
of the Incidences of chose primary -uaors that occurred ia at
least two animals ia oro group and with aa incidence of at le*st
3Z in one or acre than oaa group*
la each sax, the rest It ol :he Cochraa-
-------
(P £ 0.014) than those in the Batched controls. The statistical
conclusion 1* that ch« incidence of this tus»r ia Bale anil feaele
aj|^j^iMoclated MIrh ~ffijipiJ^ m (ua^
the; Batched controls indicates • probability level e€ 0.
which 1* above the 0.023 level required b* Che
inequelicy criterion when e aailtiole cc«peri«on i»
Zn feaalee, th«. •taclsclcel cese reeult* have probability
j _
Sreacer than O.OS.
The result of the Cochraa-Araltafe teec on the cevblaed
incidences of heaangioMaa and heaangloearcoeaa in Bole alee la
significant (P - O.C47). The Fisher exact test shove that the
incidence in the low-doee frn«P is sitniflcantljr higher (P •
0.014) than thsc ia the needled controls. Neither the Fisher
exact test results using the high-dose aalas nor the results
u*ing the feaale groups are significant.
trend in the negative direction is observed ia the
•,- -^ -,
I*ei4ettce of fPiaals with alveolar/brjpchiolar adenomas or
carcinomas of the lung in asle nice, where the incidence In the
•etched controls vxceeds the incidences in che dosec1 groups. The
i.'.
31
-------
probable reason £or this negative trend is that the dosed animals
did not live as long as the control animals, thus suppressing the
32
-------
V. D1SCUSSICM
la thi* bloaaaay, the total doses received by the "let-" and
reflect the
drinking
•t^^Ki^U^ii i^JO^^tJlm iT^a^ to»»d nt^r ^
_- -^.-'- "^^sj^sajS^rL^t^Ssa^ _- ~--z^=;~->~-
»re«~>m«b ly due i» ftart- Wl^ecreaJitf palatability .- In addition,
there were wide fluctuation* in intake at different time period*
within the group*. The mean body weights of che rat* and mica
were not consistently affected by the administration of dloxana.
*
Rate* of survival of the dosec group* of male and female rata
were lower than chose of the corresponding control*, but
sufficient number* of rats were at risk beyond week 52 on study
for development of tumors appearing within this period. There
was a positive dose-related crend in mortality in the female but
not in the male mice. Although only S6Z of the high-dose female
mice survived until the end of the bioaaaay, sufficient numbers
of both male and female nice were at risk for development of
late-appearing tumors.
In rat*, the Incidence of squ»mous-cell carcinomas of che nasal
Curbinates wm* statistically significant In cases both for dose-
related trend in females (P - 0.008) and for direct comparison of
high-dose wich control males (F < 0.001) and direct comparison of
dosed with control females (P <. 0.003) (males: controls 0/33,
33
-------
low-dose 12/33, high-dose 16/34; females: controls 0/34, lov-dose
10/35, high-dope 8/35). These carcinomas commonly invaded local
tissues and extended to Che retrobulbar tissues of the eye in one
male and to the braic in another male. In addition,
adenocarclnomas (nonkeratinlzing) arose from the nasal nucosal
epithelium in three high-dose males and in one low-dose and one
high-dose female. In the female, but not in the mile rars, Che
incidence of hepatocellular adenomas also was significant (P _<
0.001) in tests for dose—related trend and for direct comparison
of both lov- and high-dose groups with controls (controls 0/31,
low-dose 10/33, high-dose 11/32).
In both male and female mice, the incidence of hepatocellular
carcinomas was statistically significant (P <. 0.001) in cescs for
both dose-related crend and direct comparison of both low- and
high-dose groups with controls (males: controls 2/49, low—dose
18/50, high-dose 24/47; female: controls O/.tO, low-dose 12/48,
high-dose 29/37). The incidences remained significant when
hepatocellular adenomas were conbined with hepatocellular
carcinoma-'. Hesaiiuiomas or hetnangiosarcomas occurred in six
low-dose and three high-dose male mice but in no controls. The
incidence in the low-dose group was significantly higher than In
controls. Since neither the dose-related trend nor the Incidence
34
-------
in the high-dose group is significant, the tumors «re not
considered to be related to adainistration of the chemical.
Several investigators have reported induction of carcinomas in
animals by dioxane. Argus et al. (1965) reported th*t dioxane
given to male Uistar rats in drinking water at a concentration of
It was a hepatocarcinogen; 7/26 rats developed liver tumors at
days 448-455. Hoch-Ligeti et al. (1970) and Argus et al. (1973)
reported that administration of the compound to 120 male rats
(Charles River random bred, Sprague-Oawley descendant, 1950) at
concentrations of 0.7SZ to 1.82 in the driakinp water for 13
months led to the development of both hepatocellular carcinomas
and carcinomas cf the nasal cavity. Kociba et al. (1974)
maintained Sherman strain male and female rats on drinking water
containing 0, 1.0, 0.1, or 0.01Z dioxane for up to 716 days;
hepatocellular carcinomas developed in 10/66 rats at the 1Z
level, 1/100 rats at the 0.1Z level, 0/110 rats at the 0.01Z
level, and 1/106 control rats. Nasal carcinomas occurred in 3/66
rats at the 1Z level and In none t*r. any other level. The hi&h
dose used in the present bloassay -wuld be comparable to the 1Z
level used in Kociba's experiment, and nasal carcinomas ano
hepatocellular carcinomas were found tn both tescj. A relatively
high concentration of peroxide (0.109Z) was found several months
after completion of t.»e bioassay in one -if the lots of aioxane
35
-------
u*«d for rhe present study. It is not Icnovn whether peroxide was
present in the dioxane during the study. However, dioxane
containing no detectable peroxide has produced similar lesions to
those seen in this study in rat* (Argus et al., 1973). so it is
unlikely that the lesions in the current study were due to
peroxide. Torkelson et al. (1974) conducted a 2-year inhalation
study in rats with dioxane, using 111 ppm 5 days per week for 7
hours per day. Under these conditions, no lesions related to
administration of the dioxane were observed. Thus, carcinomas of
the nasal cavity cf rats were observed in both the present study
and iu previously reported studies. The hrpatoceliular
carcinomas previously reported in rats were not found in the
present study in rats, bur. they did occur in both sexes of mice,
and hepatoceilular adenomas were found in the female rats.
It is concluded that under the conditions of this bioassay,
1,4-dioxane induced hepatoceilular aienomas in female Csocine-
Mendel rsts. 1,4-Dioxane was carcinogenic in both sexes of rats,
producing squamous-'ell carcinomas of the nasal tuiblnates, and
co both s>exes of 36C3FI dec-, producing hepatocellalar
carcinomas.
36
-------
vi.
Argus, M. ?., Sohal, R. S., Bryant, C. M. , Hoch-Llgcti, C., and
Arcos, J. C., Dose-response and vsltrastrucrural aiceracions
in dioxane carcinogenesis. Eurup. J. Cancer 9:237-243,
1973. ~
Argus, M. F. , Arcos, J. C. , and Hoch-Llgetl, C. , Studies on the
carclnoKcnlc activity of protein-denaturing agents:
hcptocarcinogenicity of dioxane. J. Natl. Cancer Injt.
35:949-958, 1965.
Armitage, P. , Statistical Method.* _in Medical Research. John Uiley
& Sons, Inc., New York, 1971, "3p. 302-305.
BerenbLjm, I. , ed. , Carcinogenic'-ty Testing; ^ Report on the
Panel of Carcinogenic! ty of the Cancer Reserach Comnission
of U ICC . Vol. 2_, International Union Against Cancer, Geneva,
1969.
Cox, J). R. , Regression models and life tables. J. R. Statist.
Soc. B 34(2):187-220. 1972.
Cox, D. R. , Analysis of Binary Data. Mec.hi.cn & Co., Ltd., London,
1970, pp. 48-52.
Cart, J. J. , The cougar iion of proportions: a review of
significance tescs, confidence liaits and limits and
adjustaents for stratification. Rev. Int. Stac ist . Inst .
, 1971.
Hoch-Ligetl, C., Argus, M. F. , and Arcos, J. C. , Induction of
carcinomas in the nasal cavity of rats by dioxano. Brit. J.
Cancer 24 (1 '; 164-167. 1970.
Kaplan, E. L. and :ieier. P., Nuuparanw t ric estimation from
incooplation observations. J. Ac. Scat ist. ASSCK-.
53_:457-4Sl, 1958.
Koclba, R. J. , McCollister, S. B., Fark, C., Torkolson, .. R. ,
-nd Gehring, P. J. , 1,4-Hioxjne. I. Results of a 2 -year
ingestion study in r-«ts. Toxicoi. Appl. Pharr.ucol .
86, 1974.
37
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Linhart, M. S., Cooper, J. A., Martin, R. L., Page, N. P., and
>'eters. J. A., Carcinogenesis bioassay data system. Comp.
and Bicmed. Res. 7;230-248. 1974.
Matheson, D., Dioxane. Encyclopaedia of_ Occupational Health and
Safety. Vol. _1, McGraw-Hill Book Co., New York, 1972. p.
Miller, R. C., Jr. Simultaneous Statistical Inference.
KcCraw-Hi11 Book Co., New York. 1966, pp. 6-10.
Saffiotti, U. , Montesano, R., S«llakumar. A. R., Cefls, F., and
Kaufman, 0. C., Respiratory tract carcinogencsls in iian»t<»rs
induced by different numbers of administrations of benzo (a)
pyrene and ferric oxide. Cancer Re&. _ji:1073~ly79» 1972.
Stanford Research Institute. Stage I Chemical Dossier. August
1975.
Stecher, P. C., ed., Dioxare. The Mgrck Index; An Encyclopedia
of Chemicals and Drugs. Mercs. 4 Co., Inc., Rahway, N. J.,
1968, p. 384.
Tcrkelson, T. R., Leong, B. K. J. , Kociba, R. J. , Richtcr, U. A.,
and uchring, P. J., 1,4-Oioxane. \.l. Results of a 2-year
inhalation study in rats. Toxicol Appl. P:iarmacol.
^0:287-298, 1974.
United States International Trade Commission. Synthetic Organic
Chemicals. United States Production and Sales of
Miscellaneous Chemicals. U. S. International Trade
Commission, Washington, U.C., January, lV7t, p. 3.
38
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AP
-------
TAILE A1.
SUMMARY OF THE HiCIOENCE OF NEOPLASMS IM MALE HATS
ADMINISTERED 1.4-OISXAHE IN THE ORIN«JNG WAT63
MATCHED
CONTROL
LOW DOSC
HIGM DOST
IIXTXllLl II 3TUDT 35
IBXBAU ktCIOrSIEC 33
AIXV4U EXABX11D BISTOrATBOlCGXCAUI 33
35
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32
35
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33
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(33)
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IUABOOBXCBA
«LO>*
SMOUOOS CtLL CilCIIOni. BFTASTA
T*ANSX?X3IIL-C£U. C1SCIIOS*. RET
AOEIOCAPC:»OH1. »OS,
(3J|
(30)
(33)
12 (3M)
(31)
(31)
It (»7»)
3 (»«)
(J3)
1 (3t)
ALVCOLkfi/eiC»CHIOll* CARCXIOItl
(3*|
HEfliTuPOIETIC STSTEB
•BOWIPLE 08C41S
linPHOSA. DOS
(33)
(li)
(3«>
1
S»»COB4, »CS
t Hunas* or »»IS»LS WITH TISSOE tiA.ii.sc mcroscopic*im
• VUBodl Or AHI.1ALS H 1C 30 PS I tO
.J_Xlll_
Preceding page blank
-------
TABLE A1. MALE RATS: NEOPLASMS (CONTINUED)
IBAI31BULA1 I. 10 DE
S.OABOOS CELL CABCIBOHA, HETASTA
AiEHOCABCIIOHA. 80S. SElASTATIC
CIICIJIATCSI STSTtll
BOB A.
CICESriff STSlIfl
•LIVE*
HfcPATOCELLULA* AOE^ORA
O'lBAai STSTtB
IKIDkEY
LiPOSAICOBA
«KIBkET/COBTtI
AOEIO-IA. IOS
«OBIBAXT BLACCE3
TaABSITIOIAL-CELL CAFCIIORA
ESOOCillE STSTIH
«PITUITA«t
AuEBOHA. SOS
CbiOaOPHCIE AOZXOBA
CORTICAL AOEbonA
PbEOCHBOKCCTTCilA
«AOBiBAL CCST'IX
AOSSOCAPCIIIC.IA, IOS
tTHTiOtO
MATCHED
CONTROL LOW DOSE n.CH DOSE
(22) (15)
1 <7«)
1 (7«)
(ID U2) (J.<)
2 (6t) 1 (») 1 (J»l
1 (1»
(JD (J'l (J-M
1 (3t; 1 (Jt) 1 (Jt)
1 (j»)
(31) (J1) ;33)
' (3«)
(2H) (2) (27)
1 (J0«)
(16) (1) (15)
2 (1J«) 1 (7«)
I (
-------
TABIE A1. MALE RATS: NEO.UASMS (CONTINUED)
MATCHED
CONTROL
P«JlHCULAl-CElt CAICIMPA 1 M»)
C-CSIL AC men A ^ ;1U,,
CISTlOEIOflA. IOS
• THTIOID POLLICLE (29)
CISTADEICFA. 133
•PAIATUT10IC (25)
AOEBOIA. BOS 2 (Bf)
IP AICI EAT 1C ISLETS (2«)
BEPBOOOCTITE STSTCB
•BUI-AIT GLAB: (jj)
PiaiOADEriCAA
AJEBOCAICINONA. ios
•TE3TI3 (32)
:BTEISTXTIAL-C:LL TOBOB
• THIICA ALEUailEA (3^)
BISOTUELIOBA. IOS
ICBTOUS ST3TI3
triAii (3D
S^CABOUS tILl CAICIIOBA, BETASTA
AOEBOCAiCIICBA. IOS. BET AST AT 1C
GLIOBA. ICS
5PECIAL SEISE OBliAIS
•EIZ (-3)
At ?»OCA6ri»O«A, IOS. BETASTATIC
LOW DOSE HIGH DOSE
1 (6«)
1 (6S) 1 |JS)
(17) (3D
(•) (20
(12) U«l
1 (»«)
(31) (3«)
1 (31)
2 (41)
(2) (3D
1 (31)
(23) !31)
1 <•>*)
(23) (3D
3 (13S) 2 («*i
(29) (32)
1 (31)
2 (*«)
(33) (3«)
ROSCOLOSIEbXTAL
» iu.ii>ea or jkiudAiS aiTu T:r:ns eitmiEO SICIOSCOPICXILT
• Hi Ufa El OP AMIRALS IECIO(-2ir9
-------
TABLE A1. MALE RATS: NEOPLASMS (CONTINUED)
MATCHED
CONTROL LOW DOSE HIGH DOSE
•TOUCH TACXaALXS (J3) (J3) (>«,
BISOTHBLIOI1A, 103 ? (6f) « (12»» 5 (lit)
ALL OTBEt STSTIRS
impose riisot
LiroBA i i i
ABXHAL Disrcsnioi SOBBAIT
ABXaAfS I • ITU LIT II STOOI 15 1* 15
IATOIAL OIATHa 20 Jt 2«
aoiiBoic stcixrice 5
scHcooiiu sAciirice
ACCX9CITAILT KILLED 1
TtiniikL saciiricE JS 2 «
AHIBiL SISSXHG
« XBCLODSS AwICLIZIO tllBALS
TUdOl
TOTAL AIXAALS WI-T1 PltBAIT T080IS*
TOTAL PIIBAII TOBOI5
TOTAL AlinALS HITN BCIIC* TDBOBS
TOTAL BE IIC « TO'OtS
TOTAL AIIBAXS UITB BALICIAIT T3HOIS
TOTAL BALIGIAIT TUBOIS
TOTAL AIIBALS V ITH SBCOIOAIT
TOTAL '.ECOBOABT T'IBUIS
TOTAL AlIBkLS IITH TUBOtS QICEBTAII-
•eiici oi ri.ii-.»»iT
TOTAL OSCEBTAIM TOBOIS
TOTAL AHIBALS IXTB TOBOIS UlCriTAII-
PIXBABT OC BATASTATIC
TOTAL OICEITAll TOBOIS
70
12
17
25
IB
36
8
12
15
17
27
tl
7
11
2J
25
• PIIBAXT TOBOi^: ALL T'J«0»S IICEPT SECOIDAPT T-JBOIS
« SECOIOABI T'JBOBS: aETASTATIC fO«0«S 0« TJSOMS III¥»SI7f. INTO tl AO.IACtlt
-------
TABLE A2.
SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE RATS
ADMINISTERED 1.4-DIOXANE IN THE DRINKING WATER
MATCHED
CONTROL LOW DOSE HIGH DOSE
IIXBU.S XBITIAttI II S-.OCT "*J* ~ 35 " 35 "
AlIBAtS IECICPSIED J» J* J)
IBXailS EZABIIIO HISTOPATHOUJGICA LLJ Jl 3« 32
IITBGUBEITAIT SISTER
•S«B (J4» (35) (35)
PIBtORA 1 (Jf) 1
•SOBCUT TiSSOI (34) (J5| (J5)
PIS 10*A 1 ()S) ; (6t) 2
PIBDOSAICCaA 1 ;j»)
•r'iPXBATOBT ST2TER
•IASAL TfiailiATE ()•) (IV. (35)
S^UAaOOS CELL CA3CXKJRA 10 (29») f (23S)
AJEIOCAICIIOaA, IOS I (3%) 1
*LOIU (30) <3«) |j;>
SgUAROOS CILL CAICIIOHA. I1ETASTA 1
KERATiPOIETXC £ISTE.1
tSPL/.EI (30) <3«) (32)
HtaAIG.'OflA 2 (61)
IREStKTESIC I. NODE (J5J (5) (i)
RALICMAIT LraFhOIIA. NCS t (20%)
CIECaLATOII SISTER
•HEStNTSaiC ABT'HI (30) ;35| (j«)
;tOHA ' (IS)
SISTI.1
«tIViB U') U'> <^)
* S'jddES OP AN'.IULS WITH TISSJ! iTAHISEO .1 ICSOSCO?ICi LLI
OP *>I«ALS NETJOPSIID
-------
TABLE A2. FEMALE RATS: NEOPLASMS (CONTINUED)
HlPATOCELLUHi ADEBOBA
HABAMJlUSABCORA
•BILt OOCT
BILE DUCT AOEBOBA
OBIBAiT STSTEB
(RIOBEt
piaaosAiccRA. RETASTATIC
PlBBOAOtBCBA
HA3ABTCBA
•KIOVET/COtTIX
AOEIOBA. BOS
EBOOCmlBT STSTIB
•PITOITAiT
AOEBOHA. BOS
caaoaoPHoai AOEBOBA
(ADB4BAL
PHEUC2IOROCITOHA
ITUTBOIO
C-CELL AOEBCHA
CISTAOEBOOA. BOS
(THTBOtD POLLICLE
CISTAOEBCEk, BOS
tPABCBEiTIC ISLETS
ISLET-CELL *D!»ORA
BEPBOOUCIIfE STSTER
•RARBA«T CLABC
lL.tU.lHlL . »OS
MATCHED
CONTROL LOW DOSE HIGH DOSE
10 (301) 11 (3*1)
1 (31)
(3«) (35) (35)
1 (31)
(31) (3«) (32)
1 (31)
1 (31) 1 (31)
(31) (3«) (32)
1 (31)
(18) (3) (2)
1 (3.U)
» (221)
(30) (32) (29)
1 (31) 1 (31)
1 (3t)
(28) (20) (18)
1 («•)
(28) (20) (18)
2 (71) 1 (51)
(29) (15) (16)
1 (31)
(3«) (35) (JS)
3 (91) 3 (91) 1 (31)
«os
1 (3D
CtSTAOEBORA. NOS
HflKSBA
I BUHbEB OP AMIHALS «TH TISSUE EXiHIBEO SICBOSCOPICALLT
• 41H&3R OP AMIHAIS KEClOPSItU
-------
TABLE Al FEMALE RATS: NEOPLASMS (CONTINUED)
CONTROL LO* OOSI HIGH DOSE
PIBBOAOCICBA ij (38«)*" ~"l» j«M)10
• OTZIHS (30) (3«) (28)
AOCIIOCABCIBCHA. »os. i3»
P4»IIL1IT CISTtOMOCllCIIOfli.MOS ' 1
riBioat i
•<>*»•* (2«i (JJ) (22)
CT3T10CBCIU. IOS 1 (5t,
TMICOai 1 (kt)
BIBtKIOHA 2 (ft)
inroas ststte
• PtOITAL LOB I (31) (31) (2B)
10E»OC1ICII08*. 103. BZTUTtTIC 1 (»•)
SPECIAL SEISI CKAIS
•HAIDIIIAH CLAH (3«) (35) (J5)
AOEIOCABCilCBA, *OS, Iir%SXfB 1 (3S)
BOSCDLOSKCLZTll SISTSB
•Oil
BOOT C1TITIE5
•ASOOBIIAL k'llL ()«) t«) (35)
PIBBOSABC.1HA 1 O<) _
ALL OTHEB STSTIHS
SITE 0»|t40¥i
BTB OP »»IBALS »ITH TISSOE JXABIUBO
• »UIIBE* OP ktlnkLS HBCaOPSIZO
47
-------
TABLE A2. FEMALE RATS: NEOPLASMS (CONTINUED)
MATCHED
CONTROL LOW DOSE Hid I DOS*
SORBABT
ABIBAU IBXTXALLI II STOOT JS JS 15
BATOBAL' DEATH* Ik 29 31
HUIXBOIC SACBirice 2 1
SCaiDOLIC SAClIflCE
ACCIDIBTAL1I KILLED
SACBIUCE 21 « j
axssiie
IICLOOtS A01CLTZEO II11ALS
70801 soaniii
TOTAL kllR»L! HXTII ?IIC»*T TOHOIS* 22 29
TOTAL mam naois j« 5«
TOTAL A1IIULS UXTR BEIICI TCB01S 20 22 1*
TOTAL BEIIGI T080IS 11 «2 3«
TOTAL AltaAL! KITH HALtCHAIT TOSOtS J 12 12
TOTAL HA1ICIAIT TOdOIS J 12 U
TOTAL ANtRAl! WITH SECOMDAIT TORORS* 1 7
TOTAL SECOIOAIt TUBOIS- ) 2
TOTAL ARtaALS WITH TQilOIS OICEITAIR-
BEIiGI 01 RAIIGIAIIT
TOTAL OICIITAIII TnBO«S
TOTAL AVtRALS HITH TO (10 13 OICZB7AII-
?BX«ABT OB «IT»5TATIC
TCTAL UDCZKTAtl THROBS
• PBI8MT TONOBS: ALL TOHOiS SXCSPT SECO»0»iT TURO»S
• SECOIIOA8I TUBOBS: 1ETASTA1IC T3!1OBS 01 TOROilS IKVASKE I STO »« AOJAC!« OlOAk
-------
APPENDIX B
SUMMARY OF THE INCIDENCE OF NEOPLASMS
IN MICE ADMINISTERED 1,4-DIOXANE
IN THE DRI.MCINC WATS?.
-------
SSI
TABLE B1.
SUMMARY OP THE INCIDENCE OF NEOPLASMS IN MALE MICE
ADMINISTERED 1,4-OIOXANE IN THE ORINIGNG WATER
MATCHED
CONTROL LOW DOS* HIGH COU
ABXBALS IIXTXAILT IB STODT SO 50 JO
AIIBAi.3 IICBOPSICO «9 JO 4*
ABIBALS EXAailCD BXSTOPITHOL051CAU.T «f SO 4»
IBTCeaaSBTABT 3Y3TU
•sen
P»PILLOB». MS
BJUUBGIOSABCOBA * 1
•30BCOT TISSUE (•«) (30)
StBACCOOS AOKDOBA 1 (2t)
flBBOSABCCBA •
1
BfirXfeATJIY SISTtfl
• BASAL TOIBIIATI (»9) (SO)
AtfllOCABCUCBA, IOS 1
ILOBfl (»9) (SO) (t.7)
H»PATOCEllOLA» CAICIIOHA. BETAST 1 (21)
ALTEOLAI/erOKCHIOLAi AOEKOHA 8 (16S) 3 (At) 2 fat)
ALTBOLAB/aar »CHIOLAB CAtCISOflA 1 '2f)
BiBATOPOIETZC STSTEfl
• BULrtPLE OBCilS (•»• (SO)
BALIJIAIT ITBPHOBA. DOS 2 (U«)
ISPLtfcl (••)
Mt.« All 10.1 A 2 (•«) 2 (5«)
d.BAKilOSABCCBA 2 («i)
HL.IAiaiOSAtCCBA. BETASTATIC 1 (i»)
.1ALICIA«T 1TBPK0.1A. NOS 3 (6») ' (2*1
BAST-CLLl SARC0.1A. SETASTATIC 1 (?«)
IPAICHrATIC l.«aOE (M <2) P)
I M3B9M a? ANIPALS KITH TISSUl EXA.H«ED MICitOSCOPICi
• RUflbSB OF ADtnAlS NCCaOPSiED
Preceding page blank
51
-------
TABLE B1. MAL5 i«!CE: NCOP'.ASMS (CONTINUED)
MATCHED
CONTRCI LOW DOSE .NIGH DOSE
*"»*• <»D (%0)
BILE DOCT CARCIIOnA 1 (2S)
• PAICCAS i«?) (J«) (31)
2 (SI)
(•9) («9) ;»7)
CILL PAPILLOSA 1 (2»
SjUAdOUS CILL CAICIVOHA 1
OkIIA*T STSTCH
•OI4
IICOC«:i! SISTER
• TBT40IO tj"
PAPILLAII CT.'TAOEIIOaA. »OS 1
STSTEH
•JSEPUTiAL CtAND
(«')
f>0!
* SUflalR CP AMIBALS illTH TISSUE EIABIUFO IIIC10SCOPICALLT
• XC.1l.EB Cf AHI.1ALS
52
-------
7AM.F §1. MALE MICE: NEOPLASMS (CONTINUED)
MATCHED
r-ONTHOL i.OW OOSC HIGH DOSE
ICITOUS StSTCH
•OBI
sttczAi stist uican
•on
dOSCCLOSKCLtTil STSTEH
•Oik
•OBT CiVITHS
•041
ILL crat.4
SOHRINT
IKItlilLLT I* STOOT 50 50 SO
DEATH* 2*5
-OlliOiC SAClinCE
sc-.ioono sicairzce
KILL«0
SICIIflCt •• •* «S
I
i_ilCMlfiS5.J
I ICHBtl OF ABIHALS HtTH TISIOI EIAJII»BD IHCI05COHC1LLI
or
53
-------
TAilE 11. MALE MIC2: HEOP1A9UB (CONTINUED)
MATCHED
CONTROL
10BOa SMGAB1
TOTAL ABIBALS IITR MZBABT TOBOIS* U
TJTAL MIBAIT TUROIS 21
TOTAL ABXBALS VITR BtltCI TO HOIS 1«
TOT a*, itucx Tonoi? 17
TUTiL 1IIBAL3 fITH «»LiC»iI'. TOBOC «
TOTAL 8 ALICIA IT TU-OI5 »
TOTAL 11 III41S HtTB SICOIDAIT TOBOISI
TOTAL StCOBDAIT TU3OH3
LOWCX9SC
2i
•0
7
10
7*
30
2
5
HIGH9OSE
33
3t
»
•
27
M
1
1
TOTAL AlIBAf.S BITH T3tOIS OICZITAII-
•CliCI OB aAlZC«AIT
TOTAL OICI1TUI THROBS
TOTAL ABIBAtS HIT! TO HO IS OfeiTAXI-
MUABT OB (IITASTATIC
TOTAL OICIITAII TUHOIS
• HIBABT TOUOIS: ILL TOROBS 8ICEPT SCTOIOAIT TOHOIC
I StCOIOAIT TOIOIS: NITASTATZC TOSOJS 01 TURODS IITASITC INTO AM A9JACIIT OI11I
54
-------
TABLE B2.
SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE MICE
ADMINISTERED 1,4-OIOXANE IN THE DRINKING WATER
MATCHED
CONTROL
ABIft'.S IIITIAUT IJ STOOT 50
Ai:ai 3 aissii*:
AIIAALJ ICC90PSIED 5S
IllJUfc? EXABIUID HISTOPATHOLOGICAU.T 50
IITXS'JIinriRI SI3TEB
•S3B».UT TISSUE (50)
flBBOSAiCORA 1 (Jt)
IMAB9OI!iU!A
HtB»»CIOS»«CORi. HETISTATIC « (20f)
LOW DOSE MICH DOSE
50 50
1
«• J*
»• J4
(••) O«)
2 (*t)
1 <2«>
(••) «J«)
1 (2«)
(•7) ()«)
2 (»»)
1 (Jl!
1 (2»)
1 (2<)
(•8) ()«)
3 (if) • (101)
1 (21)
1 (2»
(«*) (37)
2 (««)
1 (2»
1 (21) • (111)
lM (»)
•A5IPOSE TISStlE
(50) (»*) (]«)
OP AMIHALS WITH TISS'JE EXtnilCC RXCI 35COPIC4 LLJ
• f.Katt Ot A»I11LS »FC80PSIEO
55
-------
TABLE B2. FEMALE MICE: NEOPLASM! (CONTINUED)
MATCHED
CONTROL
LOWOOSC
HIGH OOSC
*WltS
IIBPH08A. SOS
RAlXGItlT UBPHOBA. IDS
150)
\ (2»)
•)
1 (2t)
(J«)
(20)
ICITOUS STSTIB
* loakH OF mans mTB nssor txianco Btciosconciu.!
• I3BBEI OF AIIRALS IK1OPSIZO
-------
TA3LE 12. FEMALE MICE: NEOPLASMS (CONTINUED)
MATCHED
CONTROL LOT! DOSE HIGH OOSt
SPECIAL SEISE OIGAIS
(50) (4*) (J«)
CILi, CAiCIIOBA 1 (J»)
ril SI5TIB
•Oik
MOT CAfZTXES
•re»lTO»Zaa (SO) («•) (19)
LiaPHAICZCHA 1 (21)
ALL or a EI sTstias
•Oli
AIIBAL OZ1POSITZCI SOBRAIY
XIXTXALLI XI STOOI SO JO 50
DIATH* 5 10 JJ
SACIIPXCt
SCHEOULIO SACRXFICE
tCCZOEITALlT KILLED
SACFI7ICI • <«5 39 21
BIS SHC 1
OP 1IXIULS UITH TICSOE IZAflXICO rICI03COPICALLT
OP ill SALS MCCIOPSXEO
57
-------
TABLE KL FEMALE MICE: NEOPLASMS (COMTSHL'EO)
MATCHED
CONTROL LOW DOSE HIGH OCSE
tOBOB SOaaAIT
TOTAL ABIHALS H1TM PBIIUBT TO BO lib • 12 11 3S
TOTAL PIIBAII TOBOBS 12 *i ••
TOTAL ABtHALS HITS BCBISS TOHOIS • U *
TOTAL BEIICB T0SOB3 • U »
TOTAL ABIBAL5 KITH BALICIABT TUflOIS • 21 J«
TOTAL HAHIBABT TUBOBS a 21 J»
1
TOTAL ABXBAL3 WITH SICO»3*1T TOHOBJI 1 2
TOTAL SCCOkOABT TB(IO»S 1 4
TOTAL ABIHALS MITH TUNOIS OBCCBTAIB-
BIB13B OB BAII'IBABT
TOTAL OBCCITAIB TOTQ»I '
YOTAL ABIHAL* HITS TUSO2S OBCtlTAIB-
PBIaAFT Oi BlTASTATIC
TOTAL UBCiiTAIB TTJrOfJ
• PBUABY TUHCRS: ALL TTBOSS EI-;»?T S?COiDA»T T'JBOtS „..,.
TUPOIS: SErASTAlIC TUB0.1. 31 TUBO»S IBVAilTE UIO «• »OJACI«T 01,AB
58
-------
APPENDIX C
SUMMARY OF THE IHCIDEHCE OF NONNEUPLASTIC LESIONS
IM RATS ADMINISTERED 1,<.-DICXANE
IN THE DRINKING WATER
59
-------
TABLE C1.
SUMMARY OF THE INCIDENCE OF NONNSOR.AST1C LESIONS IN MALE RATS
ADMINISTERED 1,4-DiCXANE IN THE DRIVING WATER
ABXBALS IBXTIALIT II STOOI
ABIBALS rtCICtSIEO
kBXBAJ.5 PXABIKO HI3TOPATHOLOGXCALLX
XBTSGOBBBTABT STSTEB
• SUB
CVIOZIBAL XBCLOSXOB CTST
•SOBCOT TISSOI
6BABOLOBA. B*>S
•ISritATOB/ ITSTtB
•BA3AL TOIBIlATt
mriAaBAtia*. HCBOCIHAGIC
XII UilBAHvl. ACOTC
IBPI-AIIBkTICB. ACGTS SOPPUIATXTE
XIPIABBAIXCB, CHBCfIC
IKPLABBATIOI. ACT1TZ SUPPOIA'IVE
IBPt^BBATXwB, CHBOAIC
XkrUBBlTIOf, CHBOIXC SUPPOBATlf
.\ttSCBS3. CMMJKIC
«L3IC
O>»OE3TIO», IO5
SOEBA. BOS
PBIOBOIIt. ASPXBATXOB
PBBOBCIIA. CBIOB1C BOBXBE
BBBATOPOISTIC ZTSIEB
IBGKL HABBUl
HEBATOPOIFTIC TISSUE OXSOIOEI
BXPBBPLASXA. HEflkTOPOIZTIC
ISPLiiEB
MATCHCO
CONTROL
33
(33)
(33)
1 (31)
(33)
5 (151)
6 (181)
2 (61)
(30)
7 (2J1)
2 (71)
(30)
1 (31)
1 (31)
8 (271)
(31)
1 (31)
3 (10k)
(31)
LOW OOtt HIGH DOSC
35 35
33 .1*
32 J3
(33) (3«)
1 (31) : (31)
(33) (34)
(33) {?•)
2 (61)
2 (61)
16 (181) 1* ><7I)
(23) (3J)
2 (91) • (Ul)
1 (31)
1 (••>
(31) (33)
5 (161)
1 (31)
;s (i8i) lit (»i»)
(15) (32)
3 (201) 1 (181)
(32) (30)
* 11211 .. 3 IKU.
I MOBdCS OP »NIM»LS «TH TXSSOE EX»IIIIIE3 HICBOSCOUCi LIT
• ROBBER 0? JMU.1ALS IBCROPSIZD
Preceding page blank
61
-------
TABLE C1. MALE RATS: NONHEOPLASTIC LESIONS (CONTINUED)
MATCHED
CONTHOL
LOWOOH
s :i
HICHOOtC
BtaosiDoosis
kTinPHI. DOS
LTBPHOID CrPLCTXOB
lUHAiUPOIr.StS
• SPLiJIIC
ATBOPHT. IDS
•RAI3IBULAB I.
XBrLARaATICI. CHkOlIC
BIPEIPLASIA. LTH*HOID
• BBOBCBXAL LTRPB lODt
UBOBBBiiil
OIGE3TIVB STSTIB
ILITIR
CIST. IOS
D»G8ieiATIOI. IOS
•BCIOSiS. 7Ch.»L
(31) (32)
2-I4XJ
3 (9t)
1 (31)
(33)
7 (2 HI
» HORJ&I OF AMX.1ALS HITB TISSOI EIAalltO HXCI3SCOPXCALLT
• lORbH OP ANIRALS KKIOP5IED
62
-------
TABLE Cl. MALE RATS: NONNEOPIASTIC LESIONS (CONTINUED)
MATCHED
CONTROL
ATBOPBT, IOS
BXPEBPLA3IA. IOS 5 (1«1)
AICIECTASIS 1 (31)
• LZTU/CEBTBILOBOtAB (J1)
BBCIOSXS. IOS
• BXLi 00 CT (}3)
XB.n.ABBATXCI. CHBOBIC
HXPECPLASIA. IOS B (2*1)
IPA3CIEA3 (2«)
PESIABTEIITI3 1 («i»
•STMACfl (31)
OLCEt. BOS
OtCSB, ACOtE
OLCEB. CHBCIXC
OBXIUX STSTEB
IKXOIET (31)
ailElALIZATIOl
lirtABBATICI. ACOTE SOPPUBATIVE
ABSCESS. IOS
XBrLAD.IATICI, CHBOIIC 23 (7«1)
PIELD»EPHIITIS. CHIOIIC 1 (3*)
CALCXPXCATXOI. DXS7IOPHIC
IRXDIET/COB1IX (31)
CALCXriCATXOI. OTSTBOPHIC
(9CB1BEBAI. TISSOE (31)
• EXDIET/TOBOlt (31)
CAST. IOS
DbfiE»CIATXOI. IOS
ATBOPHT. ICS
BbUEIEIATlCX. IOS
LOWOOU
3 («)
2 (*»)
(32)
<33)
1 (3t)
3 («)
(12)
(2B)
1 (•*)
3 (lit)
1 («t)
(31)
1 (3t)
2 («t)
(31)
(31)
1 («)
(3D
20 (6St)
HICHOOK
2 (•«)
11 (JJ1)
2 («•)
(33)
2 (»«)
(2.)
(30)
S (17*)
(33)
5 (15t)
2 (tt)
(33)
(33)
(33)
1 (Jt)
\ (Jl)
lOBIMAMT BLACCI1
IOEKA. IOS
nrLAnnATicK, CHBOITC
4fli*_i
(2)
(271
t lORrtCR OF AIIRALS WITH TISSPC EIAHIIED (UCiaSCOPICALtT
• MUHUKR OP AII.1ALS !IECiOPSI£0
63
-------
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED)
UDOCklBI STSTtR
ItXTOXTABT
CXST. BOS
•AOBSBAL
HinOBIHAGE
IBiiXXCTASXS
tAOBAML COS »IX
Liroxoosxs
ATBOP8T. BOS
•fABATHTBOIO
CTST. SOS
•irnriAsii, BOS
tiraooocrxvc STSTSS
trfcOJTATE
IlflAfiSATlCI. ACTTE
XBFLAaaATXCI, CHIOIIC
• SUIBAL VESICLE
OXLATATICI. IOS
I*FLAH3ATICI. CHIOIIC
A»SCC3S, CHIOIIC
•TESTIS
ABSCESS. ICS
P&BXABfEBZtIS
CAlCXFXCAlIOri, OTSTIOfHIC
AfBOrHT. ICS
ASPeBBATOGllESXS
»TE3IIS/TOBOtI
AT8O?HT, r:CAL
MATCHED
CONTROL
(It)
2 (131)
(30)
(30)
11 (37«|
(25)
"f (l!i
(33)
1 (3D
(32)
2 (*S>
» (JflS)
1 (3»)
(32)
LOW DOSE
(1)
'7 11jf,
• (17«)
(«l
(2)
(33)
1 (3*)
(23)
1 (•«>
12 (Ut)
(23)
1 »•<>
HIQHOOSC
(15)
(13)
1 (3S|
2 («>)
(33)
1 (31)
(2«)
1 »«•«)
(31)
3 (10*)
(3.)
1C (3Jt)
1 (3*)
13 U
kBtfOUS STSTIR
•BBAII
ABSCESS. IOS
Aa5CJ5S»_£3Biifllfi
(3D
(29)
(32)
or AIIHALS WITH TISSUE EIABINEO BICKOSCJPICAH.T
or AIIHALS HXSOPSICD
-------
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED)
MATCHED
CONTROL LOW DOS* HIGH OOtt
SPECIAL seise CIGAMS
•"« (33) (33) (3»)
laPuaaATTCi, tears 3 t«O
•ETE/IETiaA (33) (33) (3«)
IJtrUSBATtCN, MS 2 («t) 1 (3«)
NSCOLOSKILITAL STSTCB
•Oik
MOT CiTITIIS
• aeSIITZIT (33) (33) (3«)
PfclXAkTtlltXS 1 (3»)
ILL oraei smias
•on
SPECIAL BOIFHCIOCT SUHBA8I
BO LISIOH (CFOITEO 1
AbCIDEcTAI Ct»TH 2
tj;o/iec«cpsi/HisTo PUP i
AtrO/IRCIOfST/M) HISTO 1 1
AUTOLTSIS.'IO (EC10PST 2 '
t IOSB8I OP A4IHA1S U tTU TISSUE tlifllltO HXCfCSCOPIC1LLT
OP tliBALS ItCIOPSItD
-------
TAILE C2.
SUMMARY OF THE INCIDENCE OF NONNEOF1AST1C LESIONS IN FEMAL2 RATS
ADMINISTERED 1.4-OIOXANE IN THE DRINKING WATER
MATCHED
CONTROL LOW DOM
ABIBtlS XBITIAILT IB STODI 35 35
4BIBALS BECBOESIBD 3« 35
IBIHALS EXABIBID HISTOPATHOLOCICALLT 31 3*
ZBT25UBCBTABT STSTU
•SBZB (3«) (35)
EPIOfiaAL IBCIOSIOB CT3T 1 (3*)
•SOBCOT TZSSOI (3») (35)
CftABOLOBA. FOBEIGB BOOT 1 (3*)
BESPIfcATOBT S1STIH
• BASH TTIBIZBATE (3«) (35)
l»rL»nHATICI, HEROfcBHAUXC 1 (3*1
XBPUtaATiCB. ACOT: i (3«) 1 (20<)
lur ABBATIOI. ACOTe SOPPOBATXTE 1 (3*) U («*»)
ZBPlAaRATIOB. ACOTE/CHBOBIC
IBPIABBATICB. CBBOBZC
ITBACHEA (24) (31)
IBPLAflaATICB, BOS 5 (17J)
ZBPLABPATIO». ACOTE 2 (61)
ZBPLARHITICB. ACOTE- SOPfOBATITE 1 (3») 5 (1*1)
laruaaAtioa, CUBOBIC
HI CHOOSE
35
32
(35)
(35)
(35)
1 (**)
1* (•«*)
1 (31)
1 (3«)
• (17*)
1 («f)
(LOBC/BBOBCROS (30) (3«) __ (32)
IBPLAHBATIOI, CHBOBZC '
ILDBfi (30) (3«) (32)
COBGESTZOB. IDS 2
IBPLABBATIOB. ACOT^ SOPPOBATI»E 1
BaoacHOPMoaoBiA ACOTE SOPPOBATI
PBBCBOBIA. C1HOBIC B3iI»E 6 (20«) 5 (15«) 25 (7B«)
ZBPIARBATICB. CHBOBIC 50PPOBATIT 1 (3*)
BBOBCHOPVfOao.lIA CHtOVZC SUPPOBA 2 i6S) 1 (3t)
I BORBEB OP ABIflALS UITH TISSUE EXABIU9 HIC10SCOPIC1LLT
or iSIBILS IECBOPSIZO
66
-------
TAUE C2. FEMALE RATS: NOMMEOPLASTIC LESIOMJ (COHTINUEfl)
auiTOPoxrrxc STSTEB
• MBf BAiaOM
MIPBtPLASIA. HEBATOPOIETIC
•SPICEI
BtaORIBACt
ZlPUflBATZCI, ACOTE
Z»fLABBA?IC». CBIOBZC
BMOSIDtlOJIS
AI10PBT. »03
auuropoziszs
••ABDZBOIAR I. »OOE
BfaoMHAdc CIST
XKfLABBATICI, ACUTE
BTPCtPLASIA, LTBPBOItf
) t (3S)
« (20J) ? (211)
(25) (S)
1 (»»»
1 (•*)
9 (20%) 3 (»0»)
(25) (S;
1 (»*)
2 (22*)
9 (100t) 3 ('OOt)
(31) (34)
(31) (J»)
|3«) <3S)
1 (3«)
HIOHOOCC
(20)
1 (51)
(32)
1 (3S)
» U5I)
O)
(5,
1 (1001)
(32)
1 I3S)
"f 1111
(3S>
BZ6£SII»8 STSTIB
(31)
(J3.«
• ROBBEI Of »«HALS HTTK TISSUE EIABIiri' HICEOSCOPICA LL»
• KOBrER OP ANIflALo NECHOPSZEO
(32)
67
-------
TABLE C2. FEMALE RATS: NONNEOPLASTIC LESIONS (CONTINUED)
IcCBCSIS, HOS
ItCSOSIS. 10CAL
•uftosis, crrrusE
BiViflOiPHCSIS fATTT
UPOIOOSI!
M.'PCBTBOPHT, MOS
HirCF/lASX*. MOS
AkGIECTASIS
HEHATOPOtiSIS
•tl VkB/CEHTR I LOSU LAD
HETABOBPNOSIS PATTT
•BXLI 03 CT
OILATATXOM. MOS
I»PLAI»nATICM, CHBOMIC
HKPEBPLASXA. MOS
IPAICICAS
IMFtAflBATICJ iXTH ri£K031S
•PAMCBfATIC COCT
HIPZ1PIASIA. KOS
•PAMC1EATIC ACINUS
AT80PMT. MOS
fSTOBACH
EOEIIA. MOS
O^CEB. AC'JIE-
CALCiriCATlOS, CTSTBOPIIIC
• CASVUC RUCOSA
UOSXOM
MATCHED
CONTROL
1 (3«)
1 (-'*)
2 (ol)
7 (23V)
1 (3f|
(3D
1 (3S)
(3*)
1 (•>*)
1 (3«)
IJ (J8t)
(29)
1 (3()
,-,,
3 <1C«)
(29)
(3D
1 (31)
(3D
LOWOOCE
3 (*«)
1 (3S)
6 (IdS)
1 (3*)
: (6*1
11 (33«|
t33)
(35)
3 (91)
05)
(15)
(15)
(31)
1 (31)
(3)1
1 (3*)
HIGH DO S«
3 (9»)
1 (31)
2 (61)
2 (6*)
17 (531)
1 (3*1
(,j,
(35)
1 (3*)
5 (1«t)
(16)
(16)
1 l6»)
(16)
1 >6«)
(30)
1 ( J*l
1 (3*)
(30)
UHIHA.T STSTtf
IKiDkCT
BiMEitALIZATIOH
Bc.lATOdA.
PIELOMtPHIITIS.
PIELONEPHHITIS. ACUTE
mfUABBATICN. CH30HIC
NOS
NOS
(3D
1 (3*1
5 <16«)
(3*1
2 (it)
.J_JJS1_.
11 («7t)
1 (31)
I NUHBEB OP A.-ISALi HITM TlSiUt EIAHINtO r.ICPOJCOPIC* LLT
OP AH1KAL3 SECHQPSIt.3
63
-------
TABLE C2. FiMALE RATS: NONNEOPLAST1C LESIONS (CONTINUED
CKIDIEY/StCUUA
RilEKALIZATlOM
(KIOKEY/TOFJil
OILATATXC1. NOS
CYST, IOS
DtGEiEIATIOl, -OS
•UIIIAIY BLACOKI
EDEMA. KOS
IIPLAflDATICI. IOS
nrtAne»ric», ACUTE
MATCHCO
CONTROL LOW DOSE
(31) ()«»
1 (3<) •> (12*)
(31) (3«)
(25) J8)
1 (««)
HIGH UOJI
(32)
1 (Jt)
(32)
2 (01)
10 (311)
1 (251)
EIOOCMIHE S7STIH
(PITDITAIY
CYST, »OS
I&OICMAL
HK10II H AGE
ItOI&IAL COITII
L1POIOOSIS
HIPSBPLASIA, »03
ITHYiOIO
CYSTIC rOLLICLES
ruLLICULAI CYST. DOS
HYPBIPhASIA, C-CILL
3 (1711
(30)
IS (S0«)
(30)
t (301)
(28)
1 («*>
1 l»I)
3 (11*|
(J) 12'
(32) (29)
t (Jt)
9 CSt) 7 (?
-------
s
)•
TABLE O. eEMALE RATS: HONNEOPLAST1C LESIONS (CONTINUED)
8IPEIPLA
-------
TABLE C2. FEMALE RAYS: NONNEOPLASTIC LESIONS (CONTINUED)
MATCHED
CONTROt COW DOSE MICH DOSE
sttcikL
lUTO/ICCICf*T/IO NISTO
10TOLISIS/iO IECIOPST
* iOBbtl OF MIIULS KITH TISSUE EXAKI1E3 RICHCSCOPIC&LLT
or AHZRAIS
71
-------
APPENDIX 0
SUMMARY UP THE INCIDENCE OF NUNNEOPLASTIC LESIONS
IN tUCF ADMINISTERED 1,4-OIUXAWS
IN THE DRINKING WATER
PR-ceding page blank 73
-------
TABLE 01.
SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN KALE MICE
AOMINISTkREO 1,4-OIOXANE IN THE ORINKJNG WATER
MATCHED
CONTROL LOW DOSE HIGH OOSE
mBAi.5 IIXTIAIK II STUDY SO V) 50
AElfALS eiASUlD SU3TOPATMOL05ICALLT »» 53 (1)
HIPtaPLASIA. KBTZCaL'Jn C!LL I (IOCS)
SY!TEH
IBIOCAROIUB (•») (50)
OF »«I^»l.S JITH TISSUC £I»fi:»tO P.ICllCSCOPlrtLLI
.ioi* or ARI^ALS s
Preceding page blank 75
-------
TABLE 01. HALS MICE: NONNEOPLASTIC LESIONS (CONTINUED)
MATCHED
CONTROL
LOW DOSE
HICHOOSC
cxctsriTE
ItCIOSXS. 103
HtPEIPLtSXA. IOS
HI7CBC" *«!*. CTSTIC
iJCXECTISXS
(SO)
2 <«•«)
J {»«)
(•7)
(111)
(Zt)
UIXIA«T STSTEH
•Oft
STSTIB
•O*t
UPlOtMCriYE SISTEH
OiL*T»TIOi, IOS
CtST, HOS
IkPLASeATXCI. DOS
ABSCESS. tCt
IVPLARRATXCI, CHBOKIC
XMPLAHiUTXC*. CHJOLIC SUPPU^tTXT
tTESfXS
caiioLont. SPCRRATXC
1 (21)
1 (2«)
(k<»)
1 (21)
(2*1
3 (•»)
2
(21)
(tt)
(21)
(J«)
US)
ictrous
•oai
SPECIAL SEVSC CIGilS
1011
STSTEII
• lOHBEl Of *IIH»LS «ITH
• «anbu or ANIMALS
CIIXIIKO IUCKOSCCPICA LLY
/'o
-------
TABLE 01. MALE MICE: NONNEOPLASTIC LESIONJ (CONTINUED)
MATCHED
CONTROL LOW DOSE
BOOT CAVITIES
•OR*
ALL OTUCI STSTIBS
•OIL
SPECIAL aCF.'JcLOCT SOBSAil
KU LUIOI tePOITBO 29 10
AUTO/3 CC10PST/HISTO PEif 1
AUTOLISIS/IC IKUOPST 1
HI&HOOSC
7
1
« ioaBca or tnSALS VITH tissue EXAHIVBO RICIOSCOPICALLI
• «aaaei or AIIBALS *r.c»opsito
77
-------
TABLE 01
SUMMARY OF TH2 INCIDENCE OF NONNEOPLAST1C LESIONS IN FEMALE MICE
ADMINISTERED 1.4-OIOXANE IN THE DRINKING WATER
MATCHED
CONTROL
ABIHALS IIITIALLT II STOOT SO
ABIHA.S 4ISSIVG
IBXHA.S -ECBCPSXED SO
ABXBA.S EZAHIB1D HISTOP ATHO LOGICA UT SO
IBTZvUaSXT-BT SISTER
•one
BISPIBATOBI STSTEB
•N15AL TOBBI.ATE (SO)
iBflAHRATIO-. ACUTE
I»rU8RATICS. ACUTE SOPPL'IATIVE
PULTP
• TBJU.HEA (»5)
PJLIP
«L'J»G (SO!
Inri.flRATICIf. KCS 2 (HI)
IkfLAHRATlCN, ACUTE
A3SCE55, IOS
HIPEB0!.' SIA, LLVEOLKIi EPITHELIDH 1 (21)
JERATOPOI2TXC .TSTEff
• SPt'-E» (SO)
t.r_AnnATic». ACOTE
LOW DOSE HIGH DOSE
SO 50
1
• 8 39
« a 39
(«J) (39)
3 (61) 5 (131)
« (81) 3 (81)
1 (2%)
(«1) (25)
1 (21)
(«7) (36)
33 (701) 32 (991)
2 (61)
1 (31)
1 (2t)
(<*<•} (37)
1 (3D
IkfLAHflATICIt, CH80HH.
AIROFHT. SOS
CIRCULATOR! SISTE.1
HTPERPLA5IA. LI1PBOID
H-RATOPOttCtS
(IIRPH MODE
HIPE3PLASIA. LI.1PHOID
«(1ES«.STES:C I. «OOE
i.rLAnnA?icM. CKSONIC
6 (1.'«)
(5)
1 (20 1\
(5)
2 l«.l)
' (2»)
(D
Ml
2 (51)
(")
' (251)
(U)
1 (251)
ES 3F AHI3ALS KITH TlSSUf EXAIUHED flICBOSCOPICAL_T
Ea or AMIRALS N
78
-------
TABLE 02. FEMALE MICE: NONNEOPLAST1C LESIONS (CONTINUED)
*" ~~ ~ ~~ ~ »» — ™— '• "•• — — ••••——••I
CXCXSIITB STSTIH
•LITES
ABSCESS, NOS
itcaosis, NOS
MTAaOBPHCSIS FATTI
UPOIOOSIS
BIPC4PLASIA. UOS
AUGIECTACIS
• HTta/d'PATCCTTES
•icaosis, ios
•PAICaEAS
ritATATIOa/OUCTS
AttSCElS. CHRONIC
LiPOGaAI'JtC.lA
•PAICaEATIC ACINUS
AiaOPHT, NOS
OaiNAkl STSTER
•KIDME-
LTBFHOCTTIC I NflA Sfl ATOR t IliflLTR
«KlDllET/^LOnERDlUS
AATLOIOOSIS
MATCHED
CONTROL LOW DOSE HIGH DOSE
(50) <»«) (37)
» (2t)
3 (US)
1 (2*1
1 (*l>
1 (2») 7 M5»)
« (6t) 2 (51)
(SO) (48) 137)
1 (2»
(26) (30) (If)
1 («I) 1 (%()
1 IS*'
1 (3D
(26) (30) (19)
1 (5»)
;50) (^8) (36|
2 (»t) 2 (Ot) 1 (JS)
(50) («8) (36)
1 (2*)
INDOCilKE STSTIfl
»0 lit
RIPPOCUCTI1?! STSTEB
•OT'iUS
HIDROSETRA
HbRORRHAGIC CYST
AoSCESS, CHRONIC
fJTEiUS/£XOC.'5TP I'JS
("9)
(8»)
I"1')
146)
(314)
( J")
• <
-------
TABLE DL FEMALE MICE: NONNEOPLASTIC LESJONS (CONTINUED)
MATCHED
CONTROL LOW COSE HIGH DOSE
lIPbAaaATICB, ACUTE 3
IlPLAflBATICB. ACUTE SUPPUBATIVE
li.UBBATICI, CHBOBIC SUPPOBATIV 1
DIFFUSE 1 (21)
CTSTIC •• (981) 26 «J7«) 23 (681)
(•*) («') (3«)
I. CUIOIIC 1 (21)
(20) (2«) (20;
CIST. BOS 5 (251) 8 <«-•«) 1 (5«)
FOLLICULAI CTST. »OS 5 (251) 2 (81)
IIPLAJIBATIOI. ACOTE SUPPOBATIVE 1 (51)
BEITOUS SISTEB
101C
SPECIAL SSBSE OICABS
IOK
nSCOLOSKSlETAl SISTER
1011
BOOT CAVITIES
BOB!
ALL OTHEI STSTIBS
ADIPOSE TISSH!
LiPOGiAlDtOBA 1
SPECIAL aOBPHOlOOT SC
-------
TABLE 01 FEMALE MICE: NONNSOPIASTIC LESIONS (CONTINUED)
(WATCHED
CONTROL LOW OOSE HIGH OOSE
iUTO/ifClCfST/HZSTO P12F
AOTULTSIS/IO ICCIOPST
« 199381 OF 1I1IUL5 VIT9 TISSCE EXAKIIIO HICIOSCOPICALLT
• IDBbU OF IB1HAU IBCIOPSIEO
81
-------
APPENDIX E
ANALYSES OF THE INCIDENCE OF HRLHARY TUMORS
IN RATS ADMINISTERED 1,4-DIOXANE
IN THE DRINKING WATER
Preceding page blank
83
-------
£•»
tit
ro
ta
co
CD
Table El. Analyses of the Incidence of Primary Timor* In Hale Rats
Administered 1,4-Dloxanu In the Drinking Mater*
High Lose Low
Topography ; Morphology Cortrol Dose
Integumentary System: Fibroma* 3/J3 (9) 1/33 (3)
P Val.ic6c»d
Relative Risk (High Dose Control)1
Lower Limit
Upper Limit
Weeks to Flr»t Observed Tumor 96 101
Nasal Turblnatt: Squamoui>-cel.\
r-iiclntiub 0/33 (0) 12/33 (36)
P Values0 »d
Relative Risk (High Dose Control)*
Lower Licit
Upper Limit
Weeks to First Observed lumor — 60
High
I'OBC
1/34 (3)
U.S.
0.324
0.006
3.787 '
110
16/34 (47)
P < 0.001
Infinite
5.328
Infinite
52
-------
Table El. Analyses of the Incidence of Primary Tutors In Hale Rats
Administered 1,4-Dloxane In Che Drinking Water*
(continued )
Horyholoty
Nasal Turblnate:
. A4«nocarclnoiaa, NOSb
P Values*.*1
Relative Risk. (High Dose Coatrol)*
Lower Llalt
Upper LlBlt
Weeks to First Observed TuBor
High l)ose
Control
0/33 (0)
Low
0/33 (0)
High
Uotc
3/34 (5)
N.S.
Infinite
0.593
IP:inlte
74
o Liver: llcpatoccllular
Adenoma or Carcinoma"
P Valucac'd
Relative klbK (lllf,h Uose Control)1
Louor Llnit
Upper Llmlt
2/31 (6)
2/32 (6)
1/33 (3)
N.S.
0.«.70
0.008
6.568
W«<>ks to First Observed Tupior
100
101
110
-------
Tanlc El. Analyses of the Incidence of Primary Tutors in Male Rata
Administered 1,4-Dloxane In the Drinking Uatnr*
(continued)
High Dose
Topography; Morphology Control
Adrenal: Pheochruuocytomab 6/30 (20)
P Valucsc«d
Relative Rlslr. (High Dcse Control)1
Lower Llult
Upper Limit
Weeks to Klrsr Observed Tumor 86
Pituitary: Chromophobc Adenoma
or Adcuoou, NUSb 3/16 (19)
P Value*0**1
Relative Risk (Hj^i. Doie Control)'
Lower _ lolt
Upper Limit
Weeks to F '. rst Observed Tumor 110
Low High
Dose Dose
0/24 (0) 2/33 (6)
U.S.
0.303
0.032
1.545
— 110
0/1 (0) 1/15 (7)
N.S.
0.356
0.007
3.840
110
-------
r
Table £1. Analyses of Che Incidence of Primary Tuaorfr In Hale Rats
Administered 1,4-Dloxane In the Drinking Water*
(continued)
High Dose
TopoRtaphy; HorpholoRy Control
Thyroid: C-cell Adenoma5 3/23 (10)
P Valuc«c«d
ReUtlvu Klsk (High Done Control)*
Lover Limit
Upper Limit
Weeks to First Observed Tumor . 110
Thyroid or Thyroid Follicle:
OB Fol 1 icul jr-ct'l 1 AUenooui,
<.'<;tl xlcnoiiu. NOS, or Carcinoma1* i/29 (10)
P Valuo^.J
Relative Klbk (High Dose Control)*
Lower Limit
Upper Limit
Weeks to First Observed Tumor 97
Low HJ gh
Dose Dose
1/17 (6) 0/31 (0)
N.S.
0.000
0.000
•.525
96
1/17 (6) 1/31 (3)
N.S.
0.312
0.006
3.626
96 85
-------
Table El. Analyses of che Incidence of Prlury Tusnrs in Kale feats
Administered 1,4-Dloxane In the Drinking Water*
(continued)
Topography; Morphology
Parathyroid: Adenoma. MOSb
High Doss
Control
2/2* (0)
Low
Dose
0/4 (0)
Relative Risk (High Dose Control)'
Lower Limit
Upper Limit
Ucoks to First observed Tumor
110
High
Dose
0/24 (0)
M.S.
0.000
0.000
3.421
o»
<4»
Cland:
P Value. c'
Relative Rl«k (High Dose Control)1
Lower Limit
Upper Limit
0/33 (0)
2/33 (6)
0/34 (0)
K.3.
Wi-r k b to F I r*t
-------
Table El. Analyses of the Incidence of Primary Tumor* la Male Rat*
Administered 1,4-Oioxane In the Drinking Water*
(<;ont In'ii'd )
\ /
\
High Dose
Topography: Morphology Control
Tunica Altuglnca o. Vaginal I**:
rviuothollom.1, NuSh 2/33 (6)
P Valaesc«d
Relative- Risk (HUU Dose Control)*
1 ow.rr Llnlt
Upper 1 Imlt
Ucrks to Firbt Observed Tumor 81
vO
0 Brain: Clloou, NOSb 0/11 (0)
e Valuc^.d
Relative Hir.k (High Dose Control)'
Lower Limit
Upper Limit
Works to Klrbt Oobcrvcd Tumor —
Low High
Dose Dose
4/33 (12) 5/34 (15)
N.S.
2.426
0.432
24.040
89 69
0/29 (0) 2/32 (6)
N.S.
Infinite
0.291
Infinite
— 92
-------
' vsant
Table F.I. Analyses of the Incidence of Primary Tjwors in .lale Ral»
Administered l,4-Dlo*ane In Drinking Water4
(contInucd)
•'Doited k,io-jp» received average doses of ?\0 or 530 mg/kg per day in drinking water.
of tunor-bcarlng antmalt ,'nunbcr of animals examined at alto (percent). Control* were
micchcd to the high-dose only nnd no statistic* arc provided for the low-stove group.
cBcneath the Incidence of tumorf In tdc high-dose KrouP 1* the prcbabllity level for the Fisher
exact test for ihc comparison of that dosed r.rouP wl^h it* matched-control group when P < 0.05$
otherwise, not significant (N.S.) la Indicated.
e ttcaJ (II) Icidlcntcs a lower Incidence in a dotted group than in a control
probability le.cl for departure Iron linear trend la given when P < 0.05 for any comparison.
t
llhc 95X confidence Interval of the relative risk between t.ie high-dose group and its control
group.
-------
A
f
Table C2. Analyse* of the Incidence of Primary Tuaors In Feule Rat»
Adalnlatered 1,4-Dloxane la the Drinking Water*
Topoaranhy; Horpholoiy
Intexuwer.rary Syittea: FlSroma^
P V»lue«c»*'
Relative Risk (Hatched Control)1
Lower Llall
Upper Llnlt
U«*ka to Firat Observed Timor
Naaal Tu'blacc*: Squa»ou«-«.«ll
Care tnoiwt**
P Val-jo»c«d
Departure I'om Linear " r«-ndj
Relative Risk (Hatched Control)**
Lowc-i- l.lalt
fpper LI nit
w--ckb lo Firut Observed Tuaor
Hatched Low
Control Poat
1/34 (3) 2/35 (6)
N.S. N.S.
1.943
0.106
111.290
115 86
0/34 (0) 10/35 (29)
f - U.008 P - 0.001
P - 0.039
Infinite
2.942
Inf Intto
— 69
High
Dote
2/35 (6)
N.S.
1.94J
0.106
111.290
84
8/35 (23)
P - 0.003
Infinite
2.258
Infinite
66
-------
Table E2. Analyses of the Incidence of Primary Tumors In Female Eats
Administered 1,4-Dloxane in Che Drinking Uatora
(continued )
Matched
Topography: Morphology Control
All Site*: llcnungloma or
llcmanglobarcoma" 0/34 (0)
P Valucsc.d N.S.
Relative Risk (Matched Control)*
Lower Limit
Upper Limit
Weeks to First. Observed Tumor
Liver: HcpatoceH-jlar Adenoma" 0/31 (0)
P Va'uesc»d P • 0.001
Relative Risk (Matched Control)1
Lowe ( Limit
Upper Limit
Weeks to First Observed Tumor —
Lou
Dose
2/35 (6)
N.S.
Infinite
0.291
Infinite
86
10/33 (30)
P - 0.001
Infinite
2.860
Infinite
73
high
Dose
3/35 (9)
N.S.
Infinite
0.593
Infinite
66
11/32 (34)
P < 0.001
Infinite
3.296
Infinite
70
-------
Table E2. Analyses of the Incidence of Primary Tumora in Female Rata
AdmlnlBCerod 1,4-Dloxane In the Drinking Water*
(conttrued)
Topography; Morphology
Pituitary: Chromophobe Adenoma
or Adenoaa, NOSb
P Valued
Relative
Weeks to
Thyroid:
P Valuesc
Relative
Ufoka LC
,d
Risk (Matched Control)*
Lower Limit
Upper Limit
First Observed Tumor
C-cell Adenoma b
,d
Risk (Matched Control)*
Lower Limit
Upper Limit
First Observed Tumor
Matched Low
Control Dose
A/18 (22) 1/3 (33)
N« S * N • S •
1.500
0.033
6.475
116 110
A/28 (14) 0/20 (0)
1' - 0.033(N) N.S.
0.000
0.000
1.4A4
115
High
Dose
0/2 (0)
N.S.
0.000
0.000
4.985
_
0/18 (0)
N.S.
0.000
0.000
1.593
-—
-------
Table £2. Analyses of the Incidence of Primary Tuaors In Feiule Rats
Administered 1,4-Dloxane In Che Drinking Water*
(continued)
Matched
Topography; HorpholoRy Control
Thyroid or Thyroid Follicle:
Cystadcnoou. NOSb 2/28 (7)
P Valued, d U.S.
Relative Risk (Hatched Control)'
Lower Limit
Upper Llrlt
Weeks to First Observed Tumor U6
Mammary Gland: Adenoma or
Cyatadcnoma. NOSb 3/34 (9)
r Valuctic>d N.S.
Relative Risk (Matched Co.itrol)f
Lower Linlt
Upper Limit
Weoks ro First Observed Tumor 113
Low
Pose
1/20 (5)
N.S.
0.700
0.012
12.3Bb
111
4/35 (11)
N.S.
1.295
0.237
8.746
73
High
Dose
1/18 (6)
N.S.
0.778
0.014
13.643
92
1/35 (3)
N.S.
0.324
0.006
3.798
84
-------
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
Administered ',V-Dioxane in the Drinking Uatera
(continued)
Topraraphy; Morphology
Mammary Gland: Flbroadcnoma^
P Valuesc-d
Kolative Ribk (Matched Control)*
Lower Limit
Upper Limit
Weeks 'o first Observed Tumor
Matched
Control
13/3 A (38)
N.S.
107
Low
Dote
16/J5 (46)
N.S.
1.196
0.645
2.249
46
High
Dose
10/35 (2Sr)
N.S.
0.74'
0.344
1.583
92
aDosed groups received average doses of 350 or 040 Eg /kg per day In drinking water.
^Number of tumor-bearing animals/number of animals examined at site (percent).
cBcneath the incidence 01 tumors in the contiol gioup is the probability level for the Cochran-
A'mltaee test when P < 0.05; otherwise, not ulgnlflcant (N.S.) !• indicated. Beneath the
Incidence of tumors in a dosed group is the probability level for the Fisher exact test for
the comparison of that dosed group with the matched-control group when P < 0.05; otherwise,
not significant (N.S.) is Indicated.
''n negative trend (N) indicates a lower Incidence In a d.jted group than in a control group.
cThc probability love* for departure from linear trend la given when P < 0.05 for any comparison.
*The 95% conflc'encc interval of the relative risk betveen each dosed group and the control group.
-------
ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS
IN MICE ADMINISTERED 1,4-DIOXANE
IN Tilt DRINKING WATER
97
-------
CD
n
CD
S-.
OKI
03
CTQ
CO
P-
DJ
d3
SK-
vO
vO
UDie ri. Anaiyben 01
Administered
Topography: MorpholoKV
Integumentary System: Flbrosarcomab
P Valuesc«d
D.-pjrtuio trom Linear Trendc
Relative Kiak (Matched Control)1
Luwfr LI nil
Upper Llmli_
We ok s to First Ubbcrvcu Tumor
Lung: Alvcolar/Bronchlolar Adenoma
or Carcinoma"
P Valucsc«d
Relative Risk (Matched Control)*
Lowci Limit
Upp^r Limit
WiH-ks to First Observed Tai:ior
ino incidence ox rrinary lunurii in ruiv
l.'-Dloxane in Che Drinking Water*
Matched Low
Control Dose
0//.9 \0) 4/50 (8)
n« o • N • 3 •
P - 0.009
Inllnlte
0.909
Infinite
77
8/A9 (16) 3/50 (6)
P - O.Oo8(N) N.S.
0.368 «
0.066
l.<«30
92 91
nttc
High
Dose
^ -.
OA9 (0)
N.S.
__
—
—
M_
3/47 (6)
N.S.
0.391
0.070
1.516
89
-------
I 1
i i
Table Fl. Analyses of the Incidence of Privacy Timor• In Hale Mice
Administered 1,4-Dloxane In the Drinking Water*
(continued)
Hatched
Topography; Horpholoxv Control
ilettttopcletic System: Ly*phoaab 0'49 (0)
P V*laeac«d N.S.
Relative klak (Hatched Control)*
Lower Limit
Upper Limit
Ueeka to Fliat Observed Tumor —
All Sites: Hemangloma or
Hemrogiosarcoma" OM9 (0)
P Valuesc»d P - 0.047
Relative Risk (Hatched Control)*
Lower L'mtt
Up^cr Limit
Weeks to First Observed Tumor
Lou
Dose
5/50 (10)
P - 0.030
Infinite
1.237
Infinite
77
6/30 (12)
P • 0.014
Infinite
1.569
Infinite
91
High
Dose
2/49 (4)
N.S.
Infinite
0.296
Infinite
91
3/49 (6)
M.S.
Infinite
0.602
Infinite
66
-------
Table H. Anal)sea of the Incidence of Prinary Tuaors In Male Mice
Administered l,4-Dl->xnne In Che Drinking Water*
(continued)
Hatched
Topoftraphy; Morphology Control
l.ivcr: llepatoccllular Carcinoma'* 2/49 (4)
V Valuouc«d P < 0.001
Relative Kibk (Hatched Control)*
Lo'jer Liol t
Upper Limit
Weeks to First Observed Tumor 93
M Liver: Hepat jccllulai:
2 Carcinoma or Adcnomab 8/49 (16)
P Valueac.d P < 0.001
Relative Risk (Matched Control)1
Lower Limit
Upper Limit
Weeks to First Utbcrvod Tumot 92
Lor*
Doae
18/50 (36)
? < 0.001
8.820
2.287
74.477
91
19/50 (38)
P - 0.014
2.328
1.086
5.517
91
High
DOS"
24/47 (51)
P < 0.001
12.511
3.406
101.955
58
28/47 (60)
P < 0.001
3.649
1.852
7.934
58
-------
Table Fl. Analyses of the Incidence of Primary Tumoro In Male Mice
Administered 1,4-Dloxane In the Drinking Water3
(runtInucd)
al)obi;d groups received average doses of 720 or U30 Dig/kg per day In drinking water.
^Number of tumor-bearing animals/number of animals examined at Bite (percent).
cBcncath the Incidence of tumorc In the control group la the probability level for the Cochran-
M-mitage tost wttun F < 0.05; otherwise, not significant (N.*>.) 10 Indicated. Beneath the
Incidence of tumor* In a dosed group is the probability level for the Fisher exact teat for
the conparison of that dosed group with the matched-control group when P < 0.05; otherwise,
not significant (N.S.) is Indicated.
*• * negative trend (N) indicates a lower incidence in a dosed group than in a control group.
eThe probability level for departure from linear trend is given when P < 0.05 fur any comparison.
o
95Z confidence Interval of the relative risk between each dosed group and the control group.
-------
Tabl" F2. Analyse* of ihe Incidence of Primary Tumors In Fciwilo Kice
Administered 1,4-Dloxane in Che Drinking Water*
I /
Hatched
Topography; Morphology Control
Lung: Alveolar /Bronchlolar Adenoma
or Carclnomab 3/50 (6)
P Valueuc>d N.S.
Relative Risk (Matched Control^
Lower Llnlt
Upper Limit
Weeks to First Observed Tumor 91
»-•
S llcmatopoletlc System: Lymphoma^ 6/50 (12)
P V<,luesc.d N.S.
Rcl&tlve Risk (Matched Control)*
Lower Limit
Upper Limit
Weeks ro first Observed Tumor 76
Low
Dose
0/47 (0)
N.S.
•1.000
c.ooo
1.766
__
8/48 (17)
N.S.
1.389
0.457
4.501
67
High '
Dose
3/36 (8)
t
N • 5 •
1.389
0.196
9.764
81
i
8/39 (21) |
i
N.S.
«
1. 709 i
0.566
5.457
86 |
j
j
1
t
t
-------
Tible F2. Analyser of the Incidence of Prlm.ry tumor it in Female Mice
Administered 1,4-Dloxane In Che Drinking Water*
(continued)
Matched
TopoRt-phy: Morphology. Control
All Slkos: Hcaianciomd or
lleoungloaarcok^" 2/50 (4)
P Viluc-c.d N.S.
Relative Risk (Matched Conttol)*
Lower Liiall
Upper Limit
Weeks to First Observed Tumor 73
Liver: I'.epatuccllulac Carcinoma*1 0/50 (0)
P Values0 «J P < 0.001
Relative Risk (Hatched Control)*
Lower Limit
Upper Limit
Weens to First Observed Tumor
Low
Dose
4/48 (8)
N.S.
2.063
0.314
22.174
87
12/48 (25)
P < 0.001
Inflnltu
3.822
Infinite
32
High
Dose
0/39 (0)
N.S.
0.000
0.000
4.305
__
29/37 (7d)
P < 0.001
Infinite
13.395
Infinite
83
-------
Table ?2. Analyses of the Incldcr.ee of Primary Tumors in Female Mice
Admlniutorod 1.4-Uioxano In tha Drinking
(continued)
Matched
Topography: Morphology Control
Liver: Hepatocellular
Carcinoma or Adenomab 0/50 (0)
P Valued.*1 P < 0.001
Relative Risk (Matched Control)'
Lover Llalt
Uppei Llalt
wcckn to First Observed Tumor —
Low
Pose
21/48 (44)
r < o.oc.'.
Infinite
7.102
Infinite
82
High
Doac
35/37 (95)
P < 0.001
Infinite
17.510
Ir finite
»1
•Dosed ground received average doses of 380 or 860 mg/kg per day In drinking water.
Dhuzber of tumor-bearing aulnaJ. i/nunber of animals examined at site (percent).
cBc.teath the Incidence of tumors in the control group is the prob Mllty level for the Cochran-
Armltage teat when P < 0.05; otherwise, not significant (H.S.) 1« indicated. Beneath the
Incidence of tumors in a dosed group Is the probability level for the Fisher exact test for
the comparison of that dosed group with the matched-control group when P < 0.05; otherwise,
not significant (M.S.) iu indicated.
°A negative trenu (N) Indicates a lower incidence in r. dosed group than in e control group.
eThe probability level for departure fro* linear trend is given when P < 0.05 for any comparison.
95Z confidence interval of the relative risk between each Oosed group and the control £roup.
-------
• Bertwr. of the Bloasaay of I,4-Dloxanea for Carcinogenicity
by the Data Evaluation/Risk Assessment Subgroup of -;he
Clearinghouse on Environment\I Carcinogens
March 7, 1973
The Clearinghouse on Environmental Carcinogens was
established in May, 1976, in compliance with DHEW Comn.lttee
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
fron academla, 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 carclnogenesis or related fields
and, collec-wively, provide expertise In chemistry, Mochemistry,
blostatlstics, toxicology, pathology, and epidemiology.
Eapresentatlves of various Governmental agencies participate
as ad hoc members. The Tata Evaluation/Risk Assessment Subgrcup
of the Clearinghouse is charged with the responsibility of
providing a poer review of reports prepaied on UCI-sponsored
bloassays of chemicals studied for carcinogen;city. It is in
this context that the below critique is given 3.". the bioassay
of i.U-Dioxane for carcinogenicity.
The primary reviewer said that 1,^-Dloxane induced
squamous-cell carcinomas of tlie nasal turbinates in treated
rats and hcpatocellular carcinomas in treated mice. He
briefly described the experimental design and conditions
under which 1,1-Dioxane was tested. In his critique, the
primary reviewer noted the poor survival among the rats
and the decreased water intake among the high dose treated
male mice. He said, however, that these shortcomings did
not effect the conclusion regarding the carcinogenicity
of l,U-Dioxane.
The secondary reviewer questioned the significance
of the decreased water intake among tr.e high doss treated
male mice. A Program staff member corjr.K»nted that the
mice may have increased their water retention .^s they
decreased their water intake. As a res-tit, l,U-Dloxane
may have concentrated in the animal urinary bladder.
Preceding page blank
107
-------
It was pointed out that epidemiologlcal studies have
shown an increased Incidence of cancer of the nose and
related passages among furniture makers. A Subgrou,; member
noted that ether studies have shown experimentally the
carcinogenlcity of 1,4-Dioxane.
A motion was made that the report on the bioassay cf
1,4-Dirxane be accepted as written'. The motion was seconded
and approved unanimously.
present were:
Gerald H. V/ogan (ChairmarJ, vaSS2.Chui:etts Institute of
Technology
Arnola Brown, Mayo Clinic
E. Cuyler Hammond, American Cancer Society
Joseph Highland, Environmental Defense Fund
Henry Pitot, University of Wisconsin Medical Center
George Roush, Jr. , Monsar.to Company
Michael Shlakln, University of California at San Diego
Subsequent to this review, changes may have been made
in the bicassay report either as a result of the review
or other reasons. Thus, certain comments ?nd criticisms
reflected in the review may no longer be appropriate.
103
._ ,. . -- ..
------- |