We conducted an exploratory study of young-onset Parkinson's disease (
YOPD) to examine occupational and environmental factors associated wit
h disease risk. This case-control study included 63 YOPD patients (dia
gnosis on or before age 50); controls (n = 68) were diagnosed with rhe
umatoid arthritis. Crude odds ratios (ORs) were computed to identify e
xposure variables for logistic regression analyses. After controlling
for the variables of race, educational level, sex, age, age at diagnos
is, and family history of Parkinson's disease (PD), PD was positively
associated with insecticide exposure (OR = 5.75, p < 0.001), past resi
dency in a fumigated house (OR = 5.25, p = 0.046), herbicide exposure
(OR = 3.22, p = 0.033), rural residency at time of diagnosis (OR = 2.7
2, p = 0.027), and nuts and seed eating 10 years before diagnosis (OR
= 1.49, p = 0. 02 1). PD was inversely associated with cigarette smoki
ng at 5 years (OR = 0.50, p = 0.027), 10 years (OR = 0.43, p = 0.012),
and 15 years (OR = 0.37, p = 0.005) before diagnosis, farm residency
(OR = 0.38, p = 0.018), and exposure to dimethyl sulfoxide (OR = 0.10,
p < 0.001). These findings are consistent with hypotheses linking PD
to exposure to pesticide agents.