How low can you go? Air pollution affects mortality at very low levels
This research investigates the impact of outdoor fine particulate air pollution (PM<sub>2.5</sub>) on mortality at very low concentrations, revealing a supralinear concentration-response relationship. The findings suggest that adhering to the World Health Organization's new guideline of 5 μg/m<sup>3</sup> could prevent an additional 1.5 million deaths annually, highlighting the importance of ongoing efforts to reduce air pollution globally.
College of Health researcher(s)
Abstract
The World Health Organization (WHO) recently released new guidelines for outdoor fine particulate air pollution (PM2.5) recommending an annual average concentration of 5 μg/m3. Yet, our understanding of the concentration-response relationship between outdoor PM2.5 and mortality in this range of near-background concentrations remains incomplete. To address this uncertainty, we conducted a population-based cohort study of 7.1 million adults in one of the world’s lowest exposure environments. Our findings reveal a supralinear concentration-response relationship between outdoor PM2.5 and mortality at very low (<5 μg/m3) concentrations. Our updated global concentration-response function incorporating this new information suggests an additional 1.5 million deaths globally attributable to outdoor PM2.5 annually compared to previous estimates. The global health benefits of meeting the new WHO guideline for outdoor PM2.5 are greater than previously assumed and indicate a need for continued reductions in outdoor air pollution around the world.