Air pollution makes older men think and speak less clearly
Air pollution causes older men to think and speak less clearly, according to researchers at Columbia University, and even short-term spikes in airborne particles can damage brain health.
In a study of nearly 1,000 white men with an average age of 69, scientists found mental performance fell after rises in air pollution a month before testing. This occurred even when peak levels of air pollution were below safety thresholds set by the World Health Organisation.
Test scores from 954 men living in Boston were compared to local levels of PM2.5s, airborne particles measuring smaller than 2.5 micrometres in diameter. The tests included tasks assessing word memory, number recall and verbal fluency.
The findings, published in Nature Aging, showed the fall in test scores was linked to higher levels of PM2.5s in the four weeks before the participants were assessed even when concentrations of PM2.5s stayed below 10 micrograms per cubic metre, the WHO guideline level routinely breached in London and many other cities.
However, the test scores were shown to be less adversely affected if the men were taking aspirin or other non-steroidal anti-inflammatory drugs, known as NSAIDs.
Xu Gao, from the Mailman School of Public Health at Columbia University and the author of the paper, said: “Our study indicates that short-term air pollution exposure may be related to short-term alterations in cognitive function and that NSAIDs may modify this relationship.”
Earlier studies suggested the painkillers may help by reducing the inflammation triggered by air pollution particles getting into the brain.
“The findings really stress the impact that air pollution is having on human health,” Dr Joanne Ryan, the head of biological neuropsychiatry and dementia research at Monash University in Melbourne, told The Guardian.
“The importance of this study is that the findings align with a potential causal link of air pollution on brain function and they suggest that it is not just the very high levels of prolonged pollution that are concerning. The study found that even relatively low levels of air pollution can negatively impact cognitive function, and over possibly short periods of time.”