Pesticide use and adult-onset asthma among male farmers in the Agricultural Health Study

Eur Respir J. 2009 Dec;34(6):1296-303. doi: 10.1183/09031936.00005509. Epub 2009 Jun 18.


Although specific pesticides have been associated with wheeze in farmers, little is known about pesticides and asthma. Data from 19,704 male farmers in the Agricultural Health Study were used to evaluate lifetime use of 48 pesticides and prevalent adult-onset asthma, defined as doctor-diagnosed asthma after the age of 20 yrs. Asthma cases were categorised as allergic (n = 127) and nonallergic (n = 314) based on their history of eczema or hay fever. Polytomous logistic regression, controlling for age, state, smoking and body mass, was used to assess pesticide associations. High pesticide exposure events were associated with a doubling of both allergic and nonallergic asthma. For ever-use, 12 individual pesticides were associated with allergic asthma and four with nonallergic asthma. For allergic asthma, coumaphos (OR 2.34; 95% CI 1.49-3.70), heptachlor (OR 2.01; 95% CI 1.30-3.11), parathion (OR 2.05; 95% CI 1.21-3.46), 80/20 mix (carbon tetrachloride/carbon disulfide) (OR 2.15; 95% CI 1.23-3.76) and ethylene dibromide (OR 2.07; 95% CI 1.02-4.20) all showed ORs of >2.0 and significant exposure-response trends. For nonallergic asthma, DDT (dichlorodiphenyltrichloroethane) showed the strongest association (OR 1.41; 95% CI 1.09-1.84), but with little evidence of increasing asthma with increasing use. Current animal handling and farm activities did not confound these results. There was little evidence that allergy alone was driving these associations. In conclusion, pesticides may be an overlooked contributor to asthma risk among farmers.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Adult
  • Aged
  • Agricultural Workers' Diseases / chemically induced
  • Agricultural Workers' Diseases / etiology*
  • Agriculture
  • Asthma / chemically induced
  • Asthma / etiology*
  • Carbon Disulfide / toxicity
  • Carbon Tetrachloride / toxicity
  • DDT / toxicity
  • Ethylene Dibromide / toxicity
  • Humans
  • Iowa
  • Male
  • Middle Aged
  • North Carolina
  • Occupational Exposure
  • Parathion / toxicity
  • Pesticides / toxicity*
  • Prospective Studies
  • Smoking
  • Surveys and Questionnaires


  • Pesticides
  • Ethylene Dibromide
  • Parathion
  • DDT
  • Carbon Tetrachloride
  • Carbon Disulfide