title: Pesticides and risk of Parkinson disease: a population-based case-control study.
abstract: BACKGROUND
  Pesticide exposures are suspected risk factors for Parkinson disease (PD), but epidemiological observations have been inconsistent.
  
  
  OBJECTIVE
  To investigate associations between pesticide exposures and idiopathic PD.
  
  
  METHODS
  Population-based case-control study.
  
  
  METHODS
  Group Health Cooperative, a health care system in western Washington State, and the University of Washington.
  
  
  METHODS
  Two hundred fifty incident PD case patients and 388 healthy control subjects (age- and sex-matched). We assessed self-reported pesticide exposures using a structured interview. 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; crop farmer: 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 lifelong 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.
authors.affiliation: Department of Neurology, University of Washington, PO Box 359739, Seattle, WA 98104, USA. jfire@u.washington.edu
authors.forename: Jordan A
authors.initials: JA
authors.lastname: Firestone
authors.forename: Terri
authors.initials: T
authors.lastname: Smith-Weller
authors.forename: Gary
authors.initials: G
authors.lastname: Franklin
authors.forename: Phillip
authors.initials: P
authors.lastname: Swanson
authors.forename: W T
authors.initials: WT
authors.lastname: Longstreth
authors.forename: Harvey
authors.initials: H
authors.lastname: Checkoway
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D018672:Community Health Planning / Q000706:statistics & numerical data*; D016001:Confidence Intervals; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010300:Parkinson Disease / Q000453:epidemiology / Q000209:etiology*; D010575:Pesticides / Q000009:adverse effects*; D012306:Risk
chemical_list: D010575:Pesticides