Long-term PM2.5 exposure linked to semantic memory decline

A new study has found that long-term exposure to fine particulate air pollution is linked to a specific decline in memory function, with an impact greater than a decade of normal aging. The research, conducted by scientists from UC Davis Health and Kaiser Permanente, indicates that microscopic pollution particles can selectively harm the type of memory essential for communication and daily independence.

The study focused on fine particulate matter known as PM2.5, particles so small they can penetrate deep into the lungs and enter the bloodstream. Researchers analyzed data from 740 adults, aged 53 to 94, who are participants in the Kaiser Permanente Study of Healthy Aging in African Americans (STAR). They estimated each participant's exposure by calculating average PM2.5 levels at their residential addresses over periods of five, ten, and seventeen years. Cognitive performance was then assessed through a series of tests.

The results showed a clear association between higher long-term PM2.5 exposure and lower scores on tests of semantic memory. Semantic memory is the brain's store of general knowledge, including facts, vocabulary, and the meanings of words, which is crucial for...