By Abdullahi Lukman
Sustained exposure to nitrogen dioxide (NO2) and fine particulate matter (PM2.5) air pollution is associated with lower scores in key cognitive abilities, particularly language skills, according to a new research published in The Journals of Gerontology, Series A.
The study analyzed data from 1,127 adults aged 65 and over who participated in the ELSA Harmonized Cognitive Assessment Protocol (ELSA-HCAP) in 2018.
Researchers examined participants’ exposure to air pollution over an eight-to-ten-year period (2008–2017) and assessed their memory, executive function, language, and overall cognitive function.
The findings revealed that individuals residing in areas with the highest levels of NO2 and PM2.5 performed worse on cognitive tests compared to those in areas with average pollution.
The strongest association was observed in language skills, with individuals in the most polluted areas scoring in the bottom third of cognitive tests assessing this ability.
Furthermore, the study indicated that different sources of air pollution had varying effects on cognitive health. Pollution from industries, home heating, and fuel combustion showed a strong link to poorer language performance.
Lead author, Dr. Giorgio Di Gessa (UCL Epidemiology & Health) stated, “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.”
He noted the consistent link with language ability, suggesting specific pollutants might affect particular cognitive processes.
The researchers suggest the link with language could be due to air pollution’s potential impact on the temporal lobe, a brain region crucial for language. However, they emphasize that further research is needed to fully understand these connections.
Consequently, the researchers urge policymakers to implement stronger air quality regulations, especially in high-pollution areas, to protect brain health as the population ages.
Professor Paola Zaninotto (UCL Epidemiology & Health), deputy director of the ELSA study, emphasized the robust evidence provided by their decade-long tracking of pollution levels, stating that it demonstrates the damaging effects of sustained pollutant exposure on people’s brains.
The study acknowledged limitations, including the 10-year timeframe for pollution data, the use of yearly averages potentially missing short-term impacts, and the study sample being limited to England.
