Cancer incidence among pesticide applicators exposed to butylate in the Agricultural Health Study (AHS)

Environ Res. 2009 Oct;109(7):860-8. doi: 10.1016/j.envres.2009.06.006. Epub 2009 Jul 16.


Although limited, epidemiologic studies suggest possible associations between butylate use and cancer risk, specifically prostate cancer and non-Hodgkin lymphoma (NHL). We examined butylate use and cancer risk more broadly in the AHS, a cohort of licensed pesticide applicators in Iowa and North Carolina. Pesticide use information was collected using self-administered questionnaires. Poisson regression was used to calculate rate ratios (RR) and 95% confidence intervals (CI). Two exposure metrics were used: lifetime exposure days (LD) and intensity-weighted lifetime exposure days (IWLD). We used two referent groups: unexposed to butylate and the lowest butylate usage category. This analysis included 19,655 applicators with complete butylate use information; 5297 applicators were exposed to butylate, making this the largest study of butylate to date. The mean follow-up time since enrollment was 9 years. Prostate cancer risk was significantly elevated among applicators in the highest LD category in both referent groups (low-exposed referent: RR(LD)=2.09, 95% CI=1.27-3.44). We observed a significantly elevated joint effect of prostate cancer family history and high butylate usage across both exposure metrics and both referent groups (low-exposed referent: RR(LD)=2.00, 95% CI=1.07-3.74), and a non-significant, elevated interaction between butylate use and prostate cancer family history, similar to a previous AHS finding. Statistically significant increased risks and exposure-response trends were seen for all lymphohematopoietic cancers (AL) and NHL for both exposure metrics and referent groups (low-exposed referent: AL:RR(LD)=2.27, 95% CI=1.18-4.37; NHL: RR(LD)=3.44, 95% CI=1.29-9.21). Our analysis did not find meaningful associations for other cancers analyzed. Further study is warranted for AL, NHL and prostate cancers.

Publication types

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

MeSH terms

  • Adult
  • Agricultural Workers' Diseases / chemically induced*
  • Agricultural Workers' Diseases / epidemiology
  • Cohort Studies
  • Female
  • Humans
  • Iowa / epidemiology
  • Lymphoma, Non-Hodgkin / chemically induced*
  • Lymphoma, Non-Hodgkin / epidemiology
  • Male
  • Middle Aged
  • North Carolina / epidemiology
  • Occupational Exposure / adverse effects*
  • Pesticides / poisoning*
  • Prevalence
  • Prospective Studies
  • Prostatic Neoplasms / chemically induced*
  • Prostatic Neoplasms / epidemiology
  • Surveys and Questionnaires
  • Thiocarbamates / poisoning*


  • Pesticides
  • Thiocarbamates
  • butylate