Brazil has experienced unprecedented wildfires recently. We aimed to investigate the association of wildfire-related fine particulate matter (PM) with cause-specific cardiovascular mortality, and to estimate the attributable mortality burden. Exposure to wildfire-related PM was defined as exposure to annual mean wildfire-related PM concentrations in the 1-year prior to death. The variant difference-in-differences method was employed to explore the wildfire-related PM-cardiovascular mortality association. We found that, in Brazil, compared with the population in the first quartile (Q1: ≤1.82 μg/m) of wildfire-related PM exposure, those in the fourth quartile (Q4: 4.22–17.12 μg/m) of wildfire-related PM exposure had a 2.2% (RR: 1.022, 95% CI: 1.013–1.032) higher risk for total cardiovascular mortality, 3.1% (RR: 1.031, 95% CI: 1.014–1.048) for ischaemic heart disease mortality, and 2.0% (RR: 1.020, 95% CI: 1.002–1.038) for stroke mortality. From 2010 to 2018, an estimation of 35,847 (95% CI: 22,424–49,177) cardiovascular deaths, representing 17.77 (95% CI: 11.12–24.38) per 100,000 population, were attributable to wildfire-related PM exposure. Targeted health promotion strategies should be developed for local governments to protect the public from the risk of wildfire-related cardiovascular premature deaths.

中文翻译：

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野火相关的 PM2.5 和心血管死亡率：巴西的双重差分分析

巴西最近经历了前所未有的山火。我们的目的是调查与野火相关的细颗粒物 (PM) 与特定原因心血管死亡率的关系，并估计可归因的死亡负担。暴露于与野火相关的 PM 被定义为在死亡前一年内暴露于与野火相关的年平均 PM 浓度。采用变体双重差分法来探讨野火相关的 PM 与心血管死亡率之间的关联。我们发现，在巴西，与野火相关 PM 暴露水平第一四分位数（Q1：≤1.82 μg/m）的人口相比，野火相关 PM 暴露水平第四四分位（Q4：4.22–17.12 μg/m）的人口PM 暴露使总心血管死亡风险增加 2.2%（RR：1.022，95% CI：1.013–1.032），使缺血性心脏病死亡率增加 3.1%（RR：1.031，95% CI：1.014–1.048），使缺血性心脏病死亡率增加 2.0% （RR：1.020，95% CI：1.002–1.038）卒中死亡率。从 2010 年到 2018 年，估计有 35,847 人（95% CI：22,424–49,177）人因心血管死亡，即每 100,000 人中有 17.77 人（95% CI：11.12–24.38）人归因于野火相关的 PM 暴露。地方政府应制定有针对性的健康促进策略，以保护公众免受与野火相关的心血管过早死亡的风险。