Long-term exposure to six gaseous air pollutants and risk of Parkinson’s Disease
This Finnish population-nested case-control (FINPARK) study investigates the association between long-term exposure to six gaseous air pollutants and PD risk. Incident PD cases ( n = 22,189) between 1996 and 2015 were identified from the Finnish medical reimbursement register maintained by the Finnish Social Security Institution. Age-, sex- and region-matched cases ( n = 148,009) were identified from the Finnish population register. Time-weighted average air pollution exposure was modelled at the residential address for 16 years preceding the PD diagnosis. We observed a marginally increased risk for PD after higher levels of exposure to O 3 (OR 1.03, 95% CI 1.00-1.06 per IQR) for exposure 6–16 years before the index date. Inverse associations were observed for NO X , NO 2 , CO and SO 2 , potentially due to the strong negative correlation with O 3 . No association with NH 3 was observed. This may suggest a possible role of ozone in PD development even at low exposure levels, which requires further studies.