Air Pollution Linked to Higher Dementia Risk, New Research Shows

Two long-time participants at the Penn Memory Center offered researchers a revealing contrast: a man exposed to high levels of PM2.5 near central Philadelphia died with extensive Alzheimer’s disease, while a woman from a less polluted suburb showed almost no Alzheimer’s pathology. Their cases reflect growing evidence that long-term exposure to fine particulate air pollution increases dementia risk.

A major study of more than 600 donated brains found that people living in areas with higher PM2.5 levels had nearly 20% greater odds of severe Alzheimer’s pathology. Additional research involving 56 million Medicare records showed a 12% higher rate of Lewy body dementia in counties with the worst pollution. Laboratory mice exposed to PM2.5 developed clear dementia-like deficits, further strengthening the link.

Despite declining U.S. pollution levels over two decades, experts warn that weakening clean-air policies and expanding fossil-fuel use could worsen risks, especially for older adults.

17-11-2025