Affiliation:
1. Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina
2. Department of Epidemiology, UNC Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina
3. Department of Biostatistics and Epidemiology, School of Public Health, Rutgers-The State University of New Jersey, Piscataway, New Jersey
4. Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland.
Abstract
Background:
Evidence from epidemiologic and laboratory studies relating pesticides to breast cancer risk is inconsistent. Women engaging in agricultural work or living in agricultural areas may experience appreciable exposures to a wide range of pesticides, including herbicides, fumigants, and fungicides.
Methods:
We examined exposure to herbicides, fumigants, and fungicides in relation to breast cancer risk among farmers’ wives with no prior history of breast cancer in the Agricultural Health Study. Women provided information on pesticide use, demographics, and reproductive history at enrollment (1993–1997) and at a 5-year follow-up interview. We used Cox proportional hazards regression to estimate associations (hazard ratios [HRs] and 95% confidence intervals [CIs]) between the women’s and their husbands’ self-reported use of individual pesticides and incident breast cancer risk.
Results:
Out of 30,594 women, 38% reported using herbicides, fumigants, or fungicides and 1,081 were diagnosed with breast cancer during a median 15.3 years of follow-up. We found elevated risk in relation to women’s ever use of the fungicide benomyl (HR = 1.6; 95% CI = 0.9, 2.7) and the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) (HR = 1.6; 95% CI = 0.8, 3.1) and to their husbands’ use of the herbicide 2-(2,4,5-trichlorophenoxy) propionic acid (2,4,5-TP) (HR = 1.5; 95% CI = 0.9, 2.7). We observed few other chemical associations and little evidence of differential risk by tumor estrogen receptor status or linear exposure-response relationships.
Conclusion:
We did not observe clear excesses between use of specific pesticides and breast cancer risk across exposure metrics, although we did observe elevated risk associated with women’s use of benomyl and 2,4,5-T and husbands’ use of 2,4,5-TP.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Subject
Health, Toxicology and Mutagenesis,Public Health, Environmental and Occupational Health,Pollution,Global and Planetary Change,Epidemiology