Parkinson’s disease (PD) affects about 2% of people aged 70 and older. Over the next 20 years, the number of individuals with PD is expected to triple. There are various theories explaining this increase, focusing on interactions between environmental factors, genetic predispositions, and other known risk factors. One environmental exposure that may play a role in PD risk is air pollution, particularly aerosolized particulate matter with a diameter of 2.5 microns or less (PM2.5). Research suggests that the ultrafine particles (≤0.1 µm) within PM2.5 could cross the blood-brain barrier, potentia…