A new study has found that people who lived in areas with high levels of leaded gasoline emissions in the 1960s and ’70s are more likely to report memory problems today — a finding that researchers say could deepen our understanding of environmental risks tied to dementia.

The study and others presented in July at the 2025 Alzheimer’s Association International Conference used data from more than 600,000 participants from the U.S. Health and Retirement Study from the University of Michigan’s Institute for Social Research.

Participants who lived in areas with higher estimated lead emissions — often tied to dense traffic and industrial zones — were significantly more likely to report poor memory. Although the Michigan study did not include cognitive testing or formal dementia diagnoses, the

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