Long-range PM2.5 pollution and health impacts from the 2023 Canadian wildfires

• 成果类型: Article
• 署名作者: Zhang, Qiang; Wang, Yuexuanzi; Xiao, Qingyang; Geng, Guannan; Davis, Steven J.; Liu, Xiaodong; Yang, Jin; Liu, Jiajun; Huang, Wenyu; He, Changpei; Luo, Binhe; Martin, Randall V.; Brauer, Michael; Randerson, James T.; He, Kebin
• 署名单位: Tsinghua University; Tsinghua University; Stanford University; Beijing Normal University; Washington University (WUSTL); University of British Columbia; Institute for Health Metrics & Evaluation; University of Washington; University of Washington Seattle; University of California System; University of California Irvine
• 刊物名称: Nature
• ISSN/ISSBN: 0028-2881
• DOI: 10.1038/s41586-025-09482-1
• 发表日期: 2025-09-18
• 关键词: fine particulate matter; fire emissions; air-pollution; global distribution; smoke; MODEL; transport; mortality; SYSTEM; aerosol

摘要

Smoke from extreme wildfires in Canada adversely affected air quality in many regions in 20231,2. Here we use satellite observations, machine learning and a chemical transport model to quantify global and regional PM2.5 (particulate matter less than 2.5 mu m in diameter) exposure and human health impacts related to the 2023 Canadian wildfires. We find that the fires increased annual PM2.5 exposure worldwide by 0.17 mu g m-3 (95% confidence interval, 0.09-0.26 mu g m-3). North America had the largest increase in annual mean exposure (1.08 mu g m-3; 0.82-1.34 mu g m-3), but there were also increases in Europe (0.41 mu g m-3; 0.32-0.50 mu g m-3) owing to long-range transport. Annual mean PM2.5 exposure in Canada increased by 3.82 mu g m-3 (3.00-4.64 mu g m-3). In the USA, the contribution of the Canadian fires to increased PM2.5 was 1.49 mu g m-3 (1.22-1.77 mu g m-3), four times as large as the contribution from the 2023 wildfires originating in the USA. We find that 354 million (277-421 million) people in North America and Europe were exposed to daily PM2.5 air pollution caused by Canadian wildfires in 2023. We estimate that 5,400 (3,400-7,400) acute deaths in North America and 64,300 (37,800-90,900) chronic deaths in North America and Europe were attributable to PM2.5 exposure to the 2023 Canadian wildfires. Our results highlight the far-reaching PM2.5 pollution and health burden that large wildfires can have in a single year.