Objectives Despite mounting evidence on epidemiological risk factors, Parkinson’s disease (PD) incidence remains largely unexplained. The purpose of this study was to test associations between occupations and PD to complement analyses of occupational exposures.

Methods We used a population-based case-control design in British Columbia, Canada, including 403 cases (users of antiparkinsonian medication) and 405 controls (from the provincial health insurance register, frequency matched on age and sex). Job histories were collected using structured questionnaires querying all jobs held since age 16. Odds ratios were calculated for associations between PD and occupational categories using unconditional logistic regression, adjusting for age, sex, and smoking.

Results Significantly elevated risks were found for social science, law and library jobs (OR 1.82; 95% CI 1.01 - 3.29); and farming and horticulture jobs (OR 2.03; 95% CI 1.10 - 3.74). Nonsignificantly elevated risks were found for gas station jobs (OR 2.55; 95% CI 0.84 - 7.72); welders (OR 2.98; 95% CI 0.78 - 11.40); and drivers of heavy equipment (OR 1.95; 95% CI 0.66 - 5.81). Reduced risks were found for management and administration jobs (OR 0.70; 95% CI 0.49 - 0.99); other health care jobs (OR 0.44; 95% CI 0.20 - 0.99); repairers (OR 0.49; 95% CI 0.22 - 1.09); and electricians (OR 0.46; 95% CI 0.17 - 1.26).

Conclusions Increased risks for social science jobs could be related to numbers of people contacted in a day and risk of infections. Severe influenza was associated with increased risk of PD but number of people contacted was not. Elevated risks for farmers are typically attributed to pesticide exposure, however our pesticide analyses did not support this attribution. Other exposures of interest for farmers could include animal contact, influenza, head injuries, and vibration from heavy equipment, all associated with PD in our study.