Overview
- Published in JAMA Neurology, the University of Pennsylvania analysis examined 602 autopsied brains from the Penn Medicine Brain Bank using address-based estimates of PM2.5 exposure.
- Higher pollution exposure was associated with more amyloid plaques and tau tangles in the brain as well as faster cognitive and functional decline in patients’ clinical records.
- Measured exposures in the cohort ranged from 5 to 17 µg/m³, compared with the current U.S. Environmental Protection Agency limit of 9 µg/m³.
- Authors stress the study is observational, note that most donors lived in the Philadelphia region, and call for independent replication before changing clinical care.
- Experts point to plausible mechanisms such as brain inflammation, oxidative stress, and disrupted microglial clearance, while not asserting that air pollution causes Alzheimer’s disease.