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

Scott Weichenthal; Lauren Pinault; Tanya Christidis; Richard T Burnett; Jeffrey R Brook; Yen Chu; Dan L Crouse; Anders C Erickson; Perry Hystad; Chi Li; Randall V Martin; Jun Meng; Amanda J Pappin; Michael Tjepkema; Aaron van Donkelaar; Crystal L Weagle; Michael Brauer

doi:10.1126/sciadv.abo3381

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

Sci Adv. 2022 Sep 30;8(39):eabo3381. doi: 10.1126/sciadv.abo3381. Epub 2022 Sep 28.

Authors

Scott Weichenthal^{1

2}, Lauren Pinault³, Tanya Christidis³, Richard T Burnett⁴, Jeffrey R Brook⁵, Yen Chu⁶, Dan L Crouse⁷, Anders C Erickson⁶, Perry Hystad⁸, Chi Li⁹, Randall V Martin^{9

10}, Jun Meng^{10

11}, Amanda J Pappin², Michael Tjepkema³, Aaron van Donkelaar^{9

10}, Crystal L Weagle⁹, Michael Brauer^{4

6}

Affiliations

¹ McGill University, Montreal, QC, Canada.
² Health Canada, Ottawa, ON, Canada.
³ Statistics Canada, Ottawa, ON, Canada.
⁴ Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
⁵ University of Toronto, Toronto, ON, Canada.
⁶ University of British Columbia, Vancouver, BC, Canada.
⁷ Health Effects Institute, Boston, MA, USA.
⁸ Oregon State University, Corvallis, OR, USA.
⁹ Dalhousie University, Halifax, NS, Canada.
¹⁰ Washington University, Saint Louis, WA, USA.
¹¹ Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON, Canada.

Abstract

The World Health Organization (WHO) recently released new guidelines for outdoor fine particulate air pollution (PM_2.5) recommending an annual average concentration of 5 μg/m³. Yet, our understanding of the concentration-response relationship between outdoor PM_2.5 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 PM_2.5 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 PM_2.5 annually compared to previous estimates. The global health benefits of meeting the new WHO guideline for outdoor PM_2.5 are greater than previously assumed and indicate a need for continued reductions in outdoor air pollution around the world.