Hazed and Confused: The Effect of Air Pollution on Dementia

This study finds that long-term exposure to fine-particulate air pollution (PM 2.5) degrades health and human capital among older adults in the U.S. by increasing their risk of developing
Alzheimer’s disease and related dementias. The study tracked the cumulative residential exposures of U.S. Medicare beneficiaries to PM 2.5 and their health from 2004 through 2013, leveraging
within-country and between-county quasi-random variation in PM 2.5 that resulted from the expansion of Clean Air Act regulations. The result suggests that a 1 ìg/m3 increase in decadal PM 2.5 increases the probability of a dementia diagnosis by 1.68%. In contrast, the estimates suggest that the federal regulation led to nearly 182,000 fewer people with dementia in 2013,
yielding $214 billion in benefits.