Mortality risk attributable to wildfire-related PM2·5 pollution: a global time series study in 749 locations
Authors: Gongbo Chen, Yuming Guo, Xu Yue, Shilu Tong, Antonio Gasparrini, Michelle L Bell, Ben Armstrong, Joel Schwartz, Jouni J K Jaakkola, Antonella Zanobetti, Eric Lavigne, Paulo Hilario Nascimento Saldiva, Haidong Kan, Dominic Royé, Ai Milojevic, Ala Overcenco, Aleš Urban, Alexandra Schneider, Alireza Entezari, Ana Maria Vicedo-Cabrera, Ariana Zeka, Aurelio Tobias, Baltazar Nunes, Barrak Alahmad, Bertil Forsberg, Shih-Chun Pan, Carmen Íñiguez, Caroline Ameling, César De la Cruz Valencia, Christofer Åström, Danny Houthuijs, Do Van Dung, Evangelia Samoli, Fatemeh Mayvaneh, Francesco Sera, Gabriel Carrasco-Escobar, Yadong Lei, Hans Orru, Ho Kim, Iulian-Horia Holobaca, Jan Kyselý, João Paulo Teixeira, Joana Madureira, Klea Katsouyanni, Magali Hurtado-Díaz, Marek Maasikmets, Martina S Ragettli, Masahiro Hashizume, Massimo Stafoggia, Mathilde Pascal, Matteo Scortichini, Micheline de Sousa Zanotti Stagliorio Coêlho, Nicolás Valdés Ortega, Niilo R I Ryti, Noah Scovronick, Patricia Matus, Patrick Goodman, Rebecca M Garland, Rosana Abrutzky, Samuel Osorio Garcia, Shilpa Rao, Simona Fratianni, Tran Ngoc Dang, Valentina Colistro, Veronika Huber, Whanhee Lee, Xerxes Seposo, Yasushi Honda, Yue Leon Guo, Tingting Ye, Wenhua Yu, Michael J Abramson, Jonathan M Samet, Shanshan Li
Journal: The Lancet Planetary Health (2021)

BackgroundMany regions of the world are now facing more frequent and unprecedentedly large wildfires. However, the association between wildfire-related PM2·5 and mortality has not been well characterised. We aimed to comprehensively assess the association between short-term exposure to wildfire-related PM2·5 and mortality across various regions of the world.MethodsFor this time series study, data on daily counts of deaths for all causes, cardiovascular causes, and respiratory causes were collected from 749 cities in 43 countries and regions during 2000–16. Daily concentrations of wildfire-related PM2·5 were estimated using the three-dimensional chemical transport model GEOS-Chem at a 0·25° × 0·25° resolution. The association between wildfire-related PM2·5 exposure and mortality was examined using a quasi-Poisson time series model in each city considering both the current-day and lag effects, and the effect estimates were then pooled using a random-effects meta-analysis. Based on these pooled effect estimates, the population attributable fraction and relative risk (RR) of annual mortality due to acute wildfire-related PM2·5 exposure was calculated.Findings65·6 million all-cause deaths, 15·1 million cardiovascular deaths, and 6·8 million respiratory deaths were included in our analyses. The pooled RRs of mortality associated with each 10 μg/m3 increase in the 3-day moving average (lag 0–2 days) of wildfire-related PM2·5 exposure were 1·019 (95% CI 1·016–1·022) for all-cause mortality, 1·017 (1·012–1·021) for cardiovascular mortality, and 1·019 (1·013–1·025) for respiratory mortality. Overall, 0·62% (95% CI 0·48–0·75) of all-cause deaths, 0·55% (0·43–0·67) of cardiovascular deaths, and 0·64% (0·50–0·78) of respiratory deaths were annually attributable to the acute impacts of wildfire-related PM2·5 exposure during the study period.InterpretationShort-term exposure to wildfire-related PM2·5 was associated with increased risk of mortality. Urgent action is needed to reduce health risks from the increasing wildfires.FundingAustralian Research Council, Australian National Health & Medical Research Council.