Massive US Study Links Air Pollution to Alzheimer’s Risk in Seniors

A nationwide analysis of 27.8 million Americans aged 65+ shows long-term PM2.5 exposure is associated with higher Alzheimer's risk, mainly through direct brain effects rather than via hypertension, stroke or depression; greater risk among those with prior stroke and in disadvantaged communities with higher pollution exposure underscores environmental justice concerns and a push for stricter air-quality standards. The study relies on ZIP-code level outdoor exposure estimates and notes that indoor/work exposure was not included, indicating a need for mechanistic follow-up research.