Pesticides and Atopic and Nonatopic Asthma among Farm Women in the Agricultural Health Study

American Journal of Respiratory and Critical Care Medicine Vol 177. pp. 11-18, (2008) © 2008 American Thoracic Society
doi: 10.1164/rccm.200706-821OC

Jane A. Hoppin1, David M. Umbach2, Stephanie J. London1, Paul K. Henneberger3, Greg J. Kullman3, Michael C. R. Alavanja4 and Dale P. Sandler1

1 Epidemiology Branch and 2 Biostatistics Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina; 3 Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Department of Health and Human Services, Morgantown, West Virginia; and 4 Occupational Epidemiology Branch, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland

Correspondence and requests for reprints should be addressed to
Jane A. Hoppin, Sc.D., NIEHS Epidemiology Branch, MD A3-05, P.O. Box 12233,
Research Triangle Park, NC 27709-2233.

Rationale: Risk factors for asthma among farm women are understudied.

Objectives: We evaluated pesticide and other occupational exposures as risk factors for adult-onset asthma.

Methods: Studying 25,814 farm women in the Agricultural Health Study, we used self-reported history of doctor-diagnosed asthma with or without eczema and/or hay fever to create two case groups: patients with atopic asthma and those with nonatopic asthma. We assessed disease-exposure associations with polytomous logistic regression.

Measurements and Main Results: At enrollment (1993‚ 1997), 702 women (2.7%) reported a doctor’s diagnosis of asthma after age 19 years (282 atopic, 420 nonatopic). Growing up on a farm (61% of all farm women) was protective for atopic asthma (odds ratio [OR], 0.55; 95% confidence interval [CI], 0.43‚ 0.70) and, to a lesser extent, for nonatopic asthma (OR, 0.83; 95%CI,0.68‚ 1.02; P value for difference = 0.008). Pesticide use was almost exclusively associated with atopic asthma. Any use of pesticides on the farm was associated only with atopic asthma (OR, 1.46; 95% CI, 1.14‚ 1.87). This association with pesticides was strongest among women who had grown up on a farm. Women who grew up on farms and did not apply pesticides had the lowest overall risk of atopic asthma (OR, 0.41; 95%CI, 0.27‚ 0.62) compared with women who neither grew upon farms nor applied pesticides. A total of 7 of 16 insecticides,2 of 11 herbicides, and 1 of 4 fungicides were significantly associated with atopic asthma; only permethrin use on crops was associated with nonatopic asthma.

Conclusions: These findings suggest that pesticides may contribute to atopic asthma, but not nonatopic asthma, among farm women.