Residential proximity to agricultural pesticide use and incidence of breast cancer in the California Teachers Study cohort.
We examined the association between residential proximity to agricultural pesticide use and breast cancer incidence among members of the California Teachers Study cohort, a large study of professional school employees with extensive information on breast cancer risk factors, followed for cancer incidence since 1995. We identified 1552 invasive breast cancer cases, diagnosed between 1996 and 1999, among 114,835 cohort members. We used California Pesticide Use Reporting data to select pesticides for analysis based on use volume, carcinogenic potential, and exposure potential; a Geographic Information System was used to estimate pesticide applications within a half-mile radius of subjects' residences. We applied Cox proportional hazard models to estimate hazard rate ratios (HR) for selected pesticides, adjusting for age, race, and socioeconomic status. We saw no association between residential proximity to recent agricultural pesticide use and invasive breast cancer incidence. HR estimates for the highest compared to the lowest exposure categories for groups of agents were as follows: probable or likely carcinogens (1.07, 95% confidence interval (CI): 0.86-1.32), possible or suggestive carcinogens (1.06, 95% CI: 0.87-1.29), mammary carcinogens (1.15, 95% CI: 0.90-1.48), and endocrine disruptors (1.03, 95% CI: 0.86-1.25). HR estimates for other groups and individual pesticides did not differ from unity, nor was there a trend for any groupings of or individual pesticides examined. Stratifying by menopausal status or family history of breast cancer did not substantially affect our results. Our analyses suggest that breast cancer incidence is not elevated in areas of recent, high agricultural pesticide use in California.
Reynolds
Peggy
P
Environmental Health Investigations Branch, California Department of Health Services, 1515 Clay Street, Suite 1700, Oakland, CA 94612, USA. preynold@dhs.ca.gov
Hurley
Susan E
SE
Goldberg
Debbie E
DE
Yerabati
Sauda
S
Gunier
Robert B
RB
Hertz
Andrew
A
Anton-Culver
Hoda
H
Bernstein
Leslie
L
Deapen
Dennis
D
Horn-Ross
Pamela L
PL
Peel
David
D
Pinder
Richard
R
Ross
R K Ronald K
RK
West
Dee
D
Wright
William E
WE
Ziogas
Argyrios
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016573:Agrochemicals / Q000506:poisoning*; D001943:Breast Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005178:Faculty; D005260:Female; D040362:Geographic Information Systems; D006798:Housing; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D010575:Pesticides / Q000506:poisoning*; D016016:Proportional Hazards Models
D016573:Agrochemicals; D010575:Pesticides