How low can you go? Air pollution affects mortality at very low levels.

Weichenthal, Scott; Pinault, Lauren; Christidis, Tanya; Burnett, Richard T; Brook, Jeffrey R; Chu, Yen; Crouse, Dan L; Erickson, Anders C et al. · Sci Adv · 2022

prospective_cohort · Level II

Where this comes from

Abstract

The World Health Organization (WHO) recently released new guidelines for outdoor fine particulate air pollution (PM<sub>2.5</sub>) recommending an annual average concentration of 5 μg/m<sup>3</sup>. Yet, our understanding of the concentration-response relationship between outdoor PM<sub>2.5</sub> 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 PM<sub>2.5</sub> and mortality at very low (<5 μg/m<sup>3</sup>) concentrations. Our updated global concentration-response function incorporating this new information suggests an additional 1.5 million deaths globally attributable to outdoor PM<sub>2.5</sub> annually compared to previous estimates. The global health benefits of meeting the new WHO guideline for outdoor PM<sub>2.5</sub> are greater than previously assumed and indicate a need for continued reductions in outdoor air pollution around the world.