Long-term air pollution exposure linked to poorer cognitive function in older adults

Older adults exposed to high levels of air pollution over a decade perform worse on cognitive tests than those living in cleaner air, according to new ELSA research.

The study, published in The Journals of Gerontology: Series A, 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 research analysed data from 1,127 adults aged 65 and over who took part in the ELSA Harmonised Cognitive Assessment Protocol (ELSA-HCAP) in 2018. Researchers examined exposure to air pollution over an 8–10 year period and assessed participants’ memory, executive function, language, and overall cognitive function.

The findings showed that people who lived in areas with the highest levels of NO₂ and PM2.5 performed worse in cognitive tests compared to those living in areas with average pollution levels. The strongest association was observed in language skills, with individuals in the most polluted areas scoring significantly lower than their peers.

The study also found that different sources of air pollution have varying effects on cognitive health. Emissions from industry, residential combustion, and biofuel, coal, oil, and natural gas combustion were particularly harmful to language performance. These findings suggest that specific pollutants, rather than general air quality, may play a crucial role in cognition.

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."

Consequently, the researchers urge policymakers to strengthen air quality regulations, particularly in areas where pollution levels remain high, to help protect brain health as the population ages.

Deputy director of the ELSA study, Professor Paola Zaninotto (UCL Epidemiology & Health), said: “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 brain”.

Reference Di Gessa, G., Bloomberg, M., So, R., Scholes, S., Byrne, T., Lee, J., Adar, S.D., & Zaninotto, P. (2025). 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. https://doi.org/10.1093/gerona/glaf060