Pesticides and risk of Parkinson disease a population-based case-control study

Background: Pesticide exposures are suspected risk factors for Parkinson disease (PD), but epidemiological A servations have been inconsistent. Objective: To investigate associations between pesticide exposures and idiopathic PD. Design: Population-based case-control study. Setting: Group Health Cooperative, a health care system in western Washington State, and the University of Washington. Participants: Two hundred fifty incident PD case patients and 388 health), control subjects (age- and sex-matched). We assessed self-reported pesticide exposures using a structured inter-view. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined using logistic regression models, controlling for age, sex, and smoking. Results: Odds ratios for occupational exposures were not significant but suggested a gradient that paralleled occupational exposures (pesticide worker OR, 2.07: 95% CI: 0.67-6.38; cropfanner: OR., 1.65; 95% CI, 0 84 -3.27; animal and crop farmer. OR, 1.10; 95% CI, 0.60-2.00; and dairy farmer: OR, 0.88; 95% CI, 0.46-1.70). Odds ratios for organophosphates paralleled the World Health Organization hazard classifications. with parathion much higher than diazinon or malathion. We also found elevated ORs from herbicides (OR, 1.41; 95% CI, 0.51-3.88) and paraquat (OR, 1.67; 95% CI, 0.22-12-76). We found no evidence of risk from home-based pesticide exposures. We found significantly increased ORs from life-long well water consumption (OR, 1.81; 95% CI, 1.02-3.21). Conclusions: The findings for occupational pesticide exposures are consistent with a growing body of information linking pesticide exposures with PD. However, the lack of significant associations. absence of associations with home-based exposures, and weak associations with rural exposures suggest that pesticides did not play a substantial etiologic role in this population. 0