Environment and Breast Cancer: Science Review

Evidence From Humans
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PAHs and PM2.5 emissions and female breast cancer incidence in metro Atlanta and rural Georgia
Parikh, P. V., Wei, Y. Int J Environ Health Res. 2016. 26:4, 458-66.
Topic area
Environmental pollutant - PAHs Air pollution
Study design
Funding agency
Not reported
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
No analysis based on menopausal status
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Female breast cancer incidence (1992-2011) for 19 counties in metro Atlanta from SEER database and NCI State Cancer Profiles with greater average > 20 annual incident female breast cancers from 2006-2010.
Exposures investigated
County-level emission density of PAH and PM2.5 (filterable + condensable) based on data from 2008 US EPA National Emissions Inventory and Census land area. PM2.5 emissions sources included industry, traffic, agriculture, construction, domestic and natural
How exposure was measured
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.
Age-adjusted based on the 2000 US standard population, county-level poverty level from US Census
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked Yes. No, if not.
Strength of associations reported
Regression coefficients reported from linear regression of county-level emissions density and breast cancer incidence, adjusted for Census poverty level:

PAH (lb/sq-mile): β 0.568 (95% CI: 0.209-0.927)
PM2.5 (ton/sq-mile): β 2.964 (95% CI: 0.468-5.459)
Results Comments
The authors do not interpret the βs, but based on the information in the article it appears that interpretation would be: A one lb/sq mile increase in PAH emissions density was associated with 0.568 more breast cancer cases per 100,000 per year A one ton/sq mile increase in PM2.5 emissions density was associated with 2.964 more breast cancer cases per 100,000 per year
Author address
Department of Community Medicine , Mercer University School of Medicine , Macon , GA , USA.
Reviewers Comments
Authors also qualitatively compared breast cancer incidence in rural Georgia (10 counties in east central region) and metro Atlanta (five counties) and compared PAH and PM2.5 emissions densities in these two areas (by summing emissions across counties and dividing by total Census land area).