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Air Pollution Might Accelerate Alzheimer's Progression
- September 11, 2025
- Dennis Thompson HealthDay Reporter
Air pollution might speed up the devastating effects of Alzheimer’s disease on the brain, a new study says.
Alzheimer’s patients exposed to higher levels of particle pollution appeared to suffer an increased buildup of toxic amyloid and tau proteins in their brains, researchers reported Sept. 8 in JAMA Neurology.
The more air pollution a person breathed, the worse the ravages of Alzheimer’s on their brains, researchers said.
They also experienced faster memory loss, impaired judgment and difficulty with basic activities of daily living, researchers found.
“This study shows that air pollution doesn’t just increase the risk of dementia — it actually makes Alzheimer’s disease worse,” senior researcher Dr. Edward Lee said in a news release. He’s co-director of the University of Pennsylvania Institute on Aging in Philadelphia.
For the study, researchers focused on the health effects of fine particulate matter produced by wildfire smoke, car exhaust, industrial emissions and construction site debris.
Particles 2.5 micrometers and smaller are about half the size of a single strand of spider web, and once inhaled can easily pass into the bloodstream to potentially harm organs like the brain, researchers said in background notes.
For the new study, researchers examined samples from more than 600 autopsies in the Penn Medicine Brain Bank. They compared the brain tissue to each person’s exposure to particle pollution, based on where they lived.
Amyloid and tau buildup in people’s brains increased by 19% for every one microgram per cubic meter increase in their exposure to particle pollution. Amyloid plaques and tau tangles are hallmarks of Alzheimer’s disease.
Clinical records also showed that people exposed to more air pollution also had worse brain decline and a more rapid onset of Alzheimer’s symptoms, including memory loss, speech difficulties and problems with decision-making, researchers said.
“In the United States, air pollution is at the lowest levels in decades, but even just a year living in an area with high levels of pollution can have a big impact on a person’s risk for developing Alzheimer’s disease,” Lee said.
“It underscores the value of environmental justice efforts that focus on reducing air pollution to improve public health,” he added.
However, because the study was observational, it could not draw a direct cause-and-effect link between air pollution and Alzheimer’s progression, researchers noted.
More information
The Environmental Protection Agency has more on particle pollution.
SOURCE: University of Pennsylvania, news release, Sept. 8, 2025
