Short-term indoor fine particulate matter exposure impedes cognitive performance and autonomic nervous system in adults

Evidence suggests short-term exposure to fine particulate matter (PM2.5) air pollution can impact health, yet its wider cognitive effects and underlying mechanisms are unknown. In this randomized single-blind crossover lab-based study, 90 working-age adults were exposed to two stable indoor PM2.5 conditions generated by candle-burning: low concentration (1.70 μg/m 3 , representing clean air) achieved via an air purifier, and high concentration (31.22 μg/m 3 , representing global average exposure) using a sham filter in the purifier. Participants' cognitive performance across various domains was assessed, alongside heart rate variability (HRV) and electrodermal activity (EDA) to appraise potential mediating mechanisms of autonomic nervous activity on cognition. Higher PM2.5 exposure resulted in lower HRV and poorer cognitive performance in attention and memory, but not in coordination or reasoning. Decreased HRV partly mediated declines in some cognitive functions. The findings could have broader implications for workforce productivity beyond direct effects on ill health.