Environment and Breast Cancer: Science Review

Evidence From Humans
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Correlation of white female breast cancer incidence trends with nitrogen dioxide emission levels and motor vehicle density patterns
Chen, F., Bina, W. F. Breast Cancer Res Treat. 2012. 132:1, 327-33.
Topic area
Environmental pollutant - Air pollution Vehicle exhaust
Study design
Funding agency
Not reported
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
No analyses by menopausal status
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Breast cancer incidence 1980-1995 in white women from 168 counties in the SEER database (includes counties in Connecticut, Hawaii, Iowa, New Mexico, Utah, Atlanta, Detroit, San Francisco/Oakland, and Seattle/Puget Sound).
Comment about participation selection
SEER database provides information on persons diagnosed with cancer and constitutes 10% of the U.S. population. Breast cancer incidence for only white women was included in this study.
Exposures investigated
Emission data of PM 10, PM 2.5, Nitrogen oxides (NOx), volatile organic components, sulfur dioxide (SO2), lead, and ammonia, available for 1940-1980 from the U.S. EPA. Monitoring data for these compounds is available for after 1980 from the U.S. EPA. Mot
How exposure was measured
Environmental sample Geographic location
Breast cancer outcome investigated
Primary incident breast cancer
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.
Strength of associations reported
84.18% of the variation in breast cancer incidence in different geographical regions between 1980-1995 can be explained by motor vehicle density (p<0.0001).

Vehicles/square mile:
1.4: RR 1.05 (p>0.05)
14.8: RR 1.22 (p<0.05)
20.4: RR 1.41 (p<0.05)
937.4: RR 1.57 (p<0.05)
Results Comments
Locations with >13 vehicles/mi2 had significantly higher breast cancer incidence than areas with <0.9 vehicles/mi2. ORs between 20.4 and 937.4 vehicle/mi2 were relatively consistent.
Author address
Department of Community Medicine, School of Medicine, Mercer University, 1550 College St., Macon, GA 31207-0001, USA. Chen_fd@mercer.edu