Pesticide exposure and risk for Parkinson's disease.
OBJECTIVE
Chronic, low-dose exposure to pesticides is suspected to increase the risk for Parkinson's disease (PD), but data are inconclusive.


METHODS
We prospectively examined whether individuals exposed to pesticides have higher risk for PD than those not exposed. The study population comprised participants in the Cancer Prevention Study II Nutrition Cohort, a longitudinal investigation of US men and women initiated in 1992 by the American Cancer Society. Follow-up surveys were conducted in 1997, 1999, and 2001. The 143,325 individuals who returned the 2001 survey and did not have a diagnosis or symptoms of PD at baseline (1992) were included in the analyses.


RESULTS
Exposure to pesticides was reported by 7,864 participants (5.7%), including 1,956 farmers, ranchers, or fishermen. Individuals exposed to pesticides had a 70% higher incidence of PD than those not exposed (adjusted relative risk, 1.7; 95% confidence interval, 1.2-2.3; p = 0.002). The relative risk for pesticide exposure was similar in farmers and nonfarmers. No relation was found between risk for PD and exposure to asbestos, chemical/acids/solvents, coal or stone dust, or eight other occupational exposures.


CONCLUSIONS
These data support the hypothesis that exposure to pesticides may increase risk for PD. Future studies should seek to identify the specific chemicals responsible for this association.
Ascherio
Alberto
A
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA. aascheri@hsph.harvard.edu
Chen
Honglei
H
Weisskopf
Marc G
MG
O'Reilly
Eilis
E
McCullough
Marjorie L
ML
Calle
Eugenia E
EE
Schwarzschild
Michael A
MA
Thun
Michael J
MJ
D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009747:Nutritional Physiological Phenomena; D010302:Parkinson Disease, Secondary / Q000139:chemically induced* / Q000453:epidemiology*; D010575:Pesticides / Q000633:toxicity*; D012306:Risk; D014481:United States / Q000453:epidemiology
D010575:Pesticides