Parkinson disease (PD) is a degenerative disease that affects 2% of the population aged 70 years and older.1 The number of individuals with PD within the population is estimated to triple in the next 20 years.2 Several theories have been formulated to explain the progressive increase in the incidence of PD. Complex interactions among environmental factors, genetic predisposition, and known risk factors have been reported through the years as possible causes.3,4 Among environmental exposures, studies have suggested air pollution, in the form of aerosolized particulate matter with a diameter 2.5 µm or less (PM2.5), is associated with increased risk of PD.5–14 The ultrafine particles (≤0.1 µm) contained within PM2.5 may cross the blood brain barrier in humans,15 leading to inflammation, oxidative stress, and microglia activation, which are potential pathogenic mechanisms for the development of PD.15–19 At this time, there are no available national datasets on ultrafine particles contained in traffic pollution; however, ultrafine particles are traffic-related pollutants,20 along with nitrogen dioxide (NO2), for which nationwide data exist.21 Additionally, previous studies have implicated NO2 exposure as a PD risk factor.22 Thus, assessing the association of PM2.5 and NO2 with PD may help provide insight into the roles of different sources of air pollution in PD risk. In addition to potentially increasing the risk of developing PD, we hypothesize that air pollution exposure may also be associated with phenotypical manifestations and treatment outcomes. To our knowledge, no studies have explored the association between PM2.5 exposure and clinical phenotypes of PD. For this reason, we conducted a population-based study using data from the Rochester Epidemiology Project (REP) medical records linkage system to explore the association between PD and air pollution exposure. We also studied the association of air pollution exposure with patient mortality, different clinical characteristics, and presence of dyskinesia.
Krzyzanowski BMullan AFTurcano PCamerucci EBower JHSavica R. Air Pollution and Parkinson Disease in a Population-Based Study. JAMA Netw Open. 2024;7(9):e2433602. doi:10.1001/jamanetworkopen.2024.33602