Breathing polluted air was linked to an increased risk for dementia, underscoring the potential for stricter air quality measures to prevent conditions like Alzheimer's disease that afflict millions of Americans.
Harvard researchers say their analysis of 16 studies links chronic intake of toxic microscopic particulates known as PM 2.5 to conditions like Alzheimer's and other forms of dementia. The EPA has been considering regulations to reduce that pollutant. Separately, the agency is limiting mercury emissions.