近日，清华大学张强团队研究了2023年加拿大野火的长期PM2.5污染和健康影响。2025年9月10日出版的《自然》杂志发表了这项成果。

20231年，加拿大极端野火产生的烟雾对许多地区的空气质量产生了不利影响。

研究组以卫星观测、机器学习和化学传输模型为主题，量化全球和区域PM2.5(颗粒物质小于2.5）与2023年加拿大野火有关的暴露和人类健康影响。研究组发现，火灾使全球PM2.5年暴露量增加了0.17 μg m^-3（95%置信区间为0.09-0.26 μg m^-3）。由于远距离运输，北美的年平均暴露量增幅最大（1.08 μg m^-3; 0.82-1.34 μg m^-3），但欧洲也有所增加（0.41 μg m^-3; 0.32-0.50 μg m^-3）。

加拿大年平均PM2.5暴露量增加了3.82 μg m^-3(3.00 - -4.64 μg m^-3)。在美国，加拿大大火对PM2.5增加的贡献为1.49 μg m^-3(1.22 - -1.77 μg m^-3)，是2023年起源于美国的野火的贡献的五倍。

研究组发现，2023年北美和欧洲有3.54亿（2.77亿-4.21亿）人每天暴露在加拿大野火造成的PM2.5空气污染中。他们估计，北美5400人（3400-7400人）的急性死亡和北美和欧洲64300人（37800-90900人）的慢性死亡可归因于2023年加拿大野火的PM2.5暴露。该研究结果突显了大型野火在一年内可能造成深远的PM2.5污染和健康负担。

附：英文原文

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

Author: 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

Issue&Volume: 2025-09-10

Abstract: 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 2.5μm 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 0.17μgm–3 (95% confidence interval, 0.09–0.26μgm–3). North America had the largest increase in annual mean exposure (1.08μgm–3; 0.82–1.34μgm–3), but there were also increases in Europe (0.41μgm–3; 0.32–0.50μgm–3) owing to long-range transport. Annual mean PM2.5 exposure in Canada increased by 3.82μgm–3 (3.00–4.64μgm–3). In the USA, the contribution of the Canadian fires to increased PM2.5 was 1.49μgm–3 (1.22–1.77μgm–3), four times as large as the contribution from the 2023 wildfires originating in the USA. We find that 354million (277–421million) 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.

DOI: 10.1038/s41586-025-09482-1

Source: https://www.nature.com/articles/s41586-025-09482-1