Prominent role of PM10 in the link between air pollution and incident Parkinson's Disease.

Air pollution has been associated with Parkinson's Disease (PD) risk, although this relationship remains unclear. We estimated yearly levels of exposure to ten air pollutants (period 2006-2018) in an Italian population cohort, the Moli-sani study (N = 24,325; ≥35 years; 51.9% women), and derived three principal components, testing their associations with incident PD risk over 23,841 participants (213 cases, median(IQR) follow-up 11.2(2.0) years). This revealed a statistically significant association of PC1 (explaining 38.2% of common variance, tagging PM10 levels), independent on sociodemographic, professional and lifestyles covariates (Hazard Ratio [95%CI] = 1.04[1.02-1.07]). The association was confirmed testing average PM10 levels during follow-up (18[13-24]% increase of PD risk per 1 μg/m increase of PM10). Among different circulating markers, lipoprotein a explained a significant proportion of this association (2.8[0.9; 8.4]%). These findings suggest PM10 as a target to lower PD risk at the population level and a potential implication of lipoprotein a in PD etiology.