Occupation and risk of parkinsonism: a multicenter case-control study.

BACKGROUND: We examined risk of parkinsonism in occupations (agriculture, education, health care, welding, and mining) and toxicant exposures (solvents and pesticides) putatively associated with parkinsonism. OBJECTIVE: To investigate occupations, specific job tasks, or exposures and risk of parkinsonism and clinical subtypes. DESIGN: Case-control. SETTING: Eight movement disorders centers in North America. PARTICIPANTS: Inclusion criteria were parkinsonism (>or=2 cardinal signs), diagnosis within 8 years of recruitment (to minimize survival bias), and ability to participate in detailed telephone interviews. Control subjects were primarily nonblood relatives or acquaintances of patients. MAIN OUTCOME MEASURES: This multicenter case-control study compared lifelong occupational and job task histories to determine associations with parkinsonism and certain clinical subtypes (postural instability and gait difficulty and age at diagnosis