Case-control study of environmental risk factors for Parkinson's disease in Belgium

The aetiology of Parkinson's disease ( PD) is unknown and said to be multifactorial. We report on a retrospective epidemiological case control study, performed in Flanders during a 3- year period, investigating known and potential environmental risk factors for PD by means of questionnaires. We investigated 423 prevalent patients and 205 spouse-controls. We found familial occurrence in 15% of the patients, a mean age of onset of 58 years, and a clear male preponderance ( male/ female ratio 1.53). Our results suggest more nulliparity among female PD patients ( 95% CI: 1.08 - 5.76). We found a discrete clustering of patients in areas with intensive metallurgic activity. Patients were more frequently employed in metallurgy than controls ( 95% CI: 1.04 - 9.20). Furthermore, patients were clearly more exposed to zinc ( 95% CI: 1.51 - 90.90) and toluene ( 95% CI: 1.03 - 58.82). Male patients report more prostatectomy- surgery ( 95% CI: 1.54 - 17.24)