A case-control study of Parkinson's disease in a horticultural region of British Columbia.

We compared personal histories of 127 cases and 245 controls to identify possible environmental risk factors for idiopathic parkinsonism (IP). Of our controls, 121 had cardiac disease (CD) and 124 were randomly selected from electoral lists (voters). Using logistic regression and adjusting for sex and age, we ran separate analyses: IP versus CD and IP versus voters. A full occupational history was collected, as was known contact with all pesticides associated with the tree fruit sector of the agricultural industry. We found a significant association between IP and having had an occupation in which exposure through handling or directly contacting pesticides was probable, but no specific chemicals were associated with IP. We conclude that although occupations involving the use of agricultural chemicals may predispose to the development of IP, it seems likely that the pathogenesis is multifactorial rather than related to a specific agent.