Environment and Breast Cancer: Science Review

Evidence From Humans
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Major differences in breast cancer risks among occupations
Morton, W. E. Journal of Occupational and Environmental Medicine. 1995. 37:3, 328-35.
Topic area
Environmental pollutant - Occupation
Study design
Other: Surveillance
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number in Cohort
Cohort:: 7368
Cohort participation rate
97% ascertainment
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Breast cancer diagnosed in 1963-1977 in Portland, Oregon, area, identified from hospital records and death certificates.
Exposure Investigated
Exposures investigated
Usual occupation
Exposure assessment comment
Very broad categories. Categories not specifically related to chemical exposures.
Statistical Analysis
Breast cancer outcome investigated
Primary breast cancer
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.
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
Age standardized rates compared using Poisson distribution
Strength of associations reported
Significantly elevated incidence among meat wrappers (possible vinyl chloride monomer exposure), gas and chemical handlers, paper mill workers, canning and bottling workers compared with "all craftswomen."
Results Comments
Possible confounding is a serious limitation. Comparisons within socioeconomic status groups may be more meaningful.
Author address
Department of Public Health and Preventive Medicine, School of Medicine, Oregon Health Sciences University, Portland 97201, USA.