Cancer incidence among pesticide applicators exposed to alachlor in the Agricultural Health Study

Am J Epidemiol. 2004 Feb 15;159(4):373-80. doi: 10.1093/aje/kwh040.


The authors evaluated the incidence of cancer among pesticide applicators with exposure to alachlor in the Agricultural Health Study, a prospective cohort study of licensed pesticide applicators in Iowa and North Carolina. A total of 49,980 pesticide applicators are included in this analysis; 26,510 applicators (53%) reported use of alachlor on the enrollment questionnaire. Detailed pesticide exposure and other information were obtained from a self-administered questionnaire completed at the time of enrollment (1993-1997). Poisson regression analysis was used to evaluate the exposure-response relations between alachlor and cancer incidence controlled for the effects of potential confounding factors. A total of 1,466 incident malignant neoplasms were diagnosed during the study period, 1993-2000. Among alachlor-exposed applicators, the authors found a significant increasing trend for incidence of all lymphohematopoietic cancers associated with lifetime exposure-days (p for trend = 0.02) and intensity-weighted exposure-days (p for trend = 0.03) to alachlor. The risks of leukemia (rate ratio = 2.83, 95% confidence interval: 0.74, 10.9) and multiple myeloma (rate ratio = 5.66, 95% confidence interval: 0.70, 45.7) were increased among applicators in the highest alachlor exposure category. Our findings suggest a possible association between alachlor application and incidence of lymphohematopoietic cancers among applicators in the Agricultural Health Study.

Publication types

  • Comparative Study

MeSH terms

  • Acetamides*
  • Adult
  • Agricultural Workers' Diseases / epidemiology*
  • Causality
  • Cohort Studies
  • Female
  • Herbicides*
  • Humans
  • Incidence
  • Iowa / epidemiology
  • Male
  • Middle Aged
  • Neoplasms / epidemiology*
  • North Carolina / epidemiology
  • Occupational Exposure / statistics & numerical data*
  • Prospective Studies
  • Reference Values


  • Acetamides
  • Herbicides
  • alachlor