Mortality risk attributable to wildfire-related PM(2.5) pollution: a global time series study in 749 locations

Published on 1 September 2021 Updated on 19 January 2024

BACKGROUND: Many regions of the world are now facing more frequent and unprecedentedly large wildfires. However, the association between wildfire-related PM(2·5) and mortality has not been well characterised. We aimed to comprehensively assess the association between short-term exposure to wildfire-related PM(2·5) and mortality across various regions of the world. METHODS: For 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 PM(2·5) were estimated using the three-dimensional chemical transport model GEOS-Chem at a 0·25°?×?0·25° resolution. The association between wildfire-related PM(2·5) 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 PM(2·5) exposure was calculated. FINDINGS: 65·6 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 ?g/m(3) increase in the 3-day moving average (lag 0-2 days) of wildfire-related PM(2·5) 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 PM(2·5) exposure during the study period. INTERPRETATION: Short-term exposure to wildfire-related PM(2·5) was associated with increased risk of mortality. Urgent action is needed to reduce health risks from the increasing wildfires.

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

Publishing year: 2021

Pages: 579-587