Breathing polluted air can impair cognitive function within just four hours, according to a new study published in Nature Communications.

Researchers at the University of Birmingham and University of Manchester found that short-term exposure to fine particulate matter (PM2.5) significantly reduces selective attention and the ability to recognize emotions. The findings suggest that even brief encounters with air pollution can affect higher-level brain functions.

The study tested 26 adults under controlled conditions, exposing them to either clean air or high levels of particulate pollution for one hour. Cognitive tests before and after exposure showed that participants had more difficulty focusing and interpreting facial expressions after breathing polluted air.

The researchers highlighted the need for further research into PM2.5 and its effects on brain health, especially long-term.