Study Reveals Air Pollution May be Linked to Decline in Brain Health Among Older Adults - Video

Long-term exposure to high levels of air pollution may harm the brain health of older adults in England, finds a new study led by UCL researchers. Findings are published in The Journals of Gerontology: Series A. The study found that exposure to nitrogen dioxide (NO₂) and fine particulate matter (PM2.5) is linked to lower scores in key cognitive abilities, particularly language skills.

The researchers analysed data from 1,127 adults aged 65 and over who took part in the ELSA Harmonised Cognitive Assessment Protocol in 2018. The team examined exposure to air pollution over an eight to 10-year period and assessed participants’ memory, executive function, language, and overall cognitive function.

Participants completed a range of well-established neurocognitive memory assessments such as the “East Boston Memory Test” and the “Wechsler Memory Scale”, alongside immediate and delayed recall, backwards counting tasks, and shape drawing.

The findings showed that individuals residing in areas with the highest levels of NO₂ and PM2.5 performed worse on cognitive tests compared to those living in areas with average pollution levels. The most compelling evidence of association was observed in language skills, with individuals in the most polluted areas scoring in the bottom third of the cognitive tests performed.

The study also found that different sources of air pollution have varying effects on cognitive health.

Lead author Dr Giorgio Di Gessa (UCL Epidemiology & Health) said: "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.

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

Reference: Giorgio DI GESSA, Mikaela Bloomberg, Rina So, Shaun Scholes, Thomas Byrne, Jinkook Lee, Sara D Adar, Paola Zaninotto, Cognitive Performance and Long-term Exposure to Outdoor Air Pollution: Findings from the Harmonised Cognitive Assessment Protocol Sub-Study of the English Longitudinal Study of Ageing (ELSA-HCAP), The Journals of Gerontology: Series A, 2025;, glaf060, https://doi.org/10.1093/gerona/glaf060