Environment and Breast Cancer: Science Review

Evidence From Humans
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Epidemiologic study of drinking water chlorination and Wisconsin female cancer mortality
Young, T. B., Kanarek, M. S., Tsiatis, A. A. Journal of the National Cancer Institute. 1981. 67:6, 1191-8.
Topic area
Environmental pollutant - Drinking water, chlorination byproducts
Study design
Other: Case-control mortality
Funding agency
Other: EPA, University of Wisconsin, Wisconsin Cli
Study Participants
Number of Cases
Cases: 2695 female deaths 1972-1977
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number of Controls
Controls: 2695 noncancer female deaths
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Cases and controls matched for age, county, and year of death. Controls were noncancer female deaths.
Exposures investigated
Residential water source at time of death. Average daily dose from chlorination over 20 years. Surface vs. groundwater. Private wells assumed nonchlorinated. Depth of groundwater, use of purification, chlorination, organic content reported by water di
How exposure was measured
GIS/geographic location
Breast cancer outcome investigated
Mortality from breast cancer
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Urbanicity, marital status, occupation
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Description of major analysis
Logistic regression
Strength of associations reported
High relative to no chlorine dose adjusted OR=1.36 (0.84-1.87)