• Posted April 10, 2025

Air Pollution Tied To Cognitive Decline Among Seniors

Air pollution might be harming the brains of seniors, increasing their risk of dementia and cognitive decline, a new study says.

Exposure to nitrogen dioxide and fine particle pollution is linked to lower scores in key thinking and memory skills, particularly language abilities, researchers recently reported in The Journals of Gerontology: Series A.

"Our study shows that air pollution is not just harmful to the lungs and heart but also to brain health, especially when people are exposed to high levels for long periods,” lead researcher Giorgio Di Gessa, a lecturer in epidemiological data science at the University College London, said in a news release.

“The most consistent links we found were with language ability, which may indicate that certain pollutants have a specific effect on particular cognitive processes,” Di Gessa added.

For the study, researchers tracked more than 1,100 seniors 65 and older participating in a British long-range study of health in aging.

The team examined people’s exposure to air pollution over an eight- to 10-year period, and compared that to their performance on memory, thinking and language skills tests.

Folks living in areas with the highest levels of nitrogen oxide and particle pollution performed worse on brain tests compared to those living in places with average pollution levels, results show.

Nitrogen oxide mainly enters the atmosphere through the combustion of fossil fuels, while particle pollution is created mostly by any type of burning that releases ash or soot, researchers said in background notes.

Language skills suffered most from exposure to air pollution, with people in the most polluted areas scoring in the lowest third of the brain tests performed, researchers said.

In fact, results showed a dose-response relationship between air pollution and language skills – the worse the air got, the worse people performed on language tests.

One potential explanation for this link could be that air pollutants impair the brain’s temporal lobe, the part of the brain essential for language and fluency, researchers said. This association has been observed in prior studies.

However, researchers also found associations between air pollution and lower scores on planning and memory skills.

“By tracking pollution levels over a decade using high-quality data, our research provides robust evidence that sustained exposure to pollutants is damaging people’s brains,” senior researcher Paola Zaninotto, a professor of medical and social statistics at University College London, said in a news release.

More information

The University of California-Davis has more on air pollution and brain health.

SOURCE: University College London, news release, April 6, 2025