Pesticide Exposure and Risk of Rheumatoid Arthritis among Licensed Male Pesticide Applicators in the Agricultural Health Study

Environ Health Perspect. 2017 Jul 14;125(7):077010. doi: 10.1289/EHP1013.


Background: The occupation of farming has been associated with rheumatoid arthritis (RA); pesticides may account for this association, but there are few studies.

Objectives: We investigated associations between RA and use of pesticides in the Agricultural Health Study.

Methods: The study sample was drawn from male pesticide applicators enrolled in 1993–1997 who provided questionnaire data at baseline and at least once during follow-up (over a median 18 y; interquartile range 16–19). Incident RA cases (n=220), confirmed by physicians or by self-reported use of disease-modifying antirheumatic drugs, were compared with noncases (n=26,134) who did not report RA. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression, adjusting for enrollment age, state, smoking pack-years, and education. We evaluated the association of RA with the use of 46 pesticides and across 4 levels (never use and tertiles) of lifetime days of use for 16 pesticides with OR≥1.2 for ever use.

Results: Incident RA was associated with ever use of fonofos (OR = 1.70; 95% CI: 1.22, 2.37), carbaryl (OR = 1.51; 95% CI: 1.03, 2.23), and chlorimuron ethyl (OR = 1.45; 95% CI: 1.01, 2.07) compared with never use. Statistically significant exposure–response trends in association with RA were observed for lifetime days of use of atrazine [ORtertile3= 1.62 (95% CI: 1.09, 2.40); ptrend=0.01] and toxaphene [ORtertile3= 2.42 (95% CI: 1.03, 5.68); ptrend=0.02]. Exposure–response was nonlinear for fonofos [ORtertile1= 2.27 (95% CI: 1.44, 3.57); ORtertile2= 0.98 (95% CI: 0.54, 1.80); ORtertile3= 2.10 (95% CI: 1.32, 3.36); ptrend=0.005] and suggestive for carbaryl (ptrend=0.053).

Conclusions: Our results provide novel evidence of associations between exposure to some pesticides and RA in male farmers.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Agricultural Workers' Diseases / chemically induced
  • Agricultural Workers' Diseases / epidemiology*
  • Arthritis, Rheumatoid / chemically induced
  • Arthritis, Rheumatoid / epidemiology*
  • Humans
  • Iowa / epidemiology
  • Logistic Models
  • Male
  • Middle Aged
  • North Carolina / epidemiology
  • Occupational Exposure*
  • Odds Ratio
  • Pesticides / toxicity*
  • Prevalence
  • Risk Factors
  • Surveys and Questionnaires


  • Pesticides