Abstract：
The global increase in wildfires, primarily driven by climate change, significantly affects air quality and health. Wildfire-emitted particulate matter (WFPM) is linked to adverse health effects, yet the toxicological mechanisms are not fully understood given its physicochemical complexity and the lack of spatiotemporal exposure data. This study focuses on the physicochemical characterization of WFPM from a Canadian wildfire in June 2023, which affected over 100 million people in the US Northeast, particularly around New Jersey/New York. Aerosol systems were deployed to characterize WFPM during the 3 day event, revealing unprecedented mass concentrations mainly in the WFPM0.1 and WFPM0.1-2.5 size fractions. Peak WFPM2.5 concentrations reached 317 μg/m3, nearly 10 times the National Ambient Air Quality Standard (NAAQS) 24 h average limit. Chemical analysis showed a high organic-to-total carbon ratio (96%), consistent with brown carbon wildfires nanoparticles. Large concentrations of high-molecular-weight PAHs were found predominantly bound to WFPM0.1, with retene, a molecular marker of biomass burning and a known teratogen, being the most abundant (>70%). Computational modeling estimated a total lung deposition of 9.15 mg over 72 h, highlighting the health risks of WFPM, particularly due to its long-distance travel capability and impact on densely populated areas.
摘要：
全球野火的增加，主要由气候变化驱动，严重影响空气质量和健康。野火排放的颗粒物（WFPM）与不利的健康影响有关，然而，由于其物理化学复杂性和缺乏时空暴露数据，毒理学机制尚未完全理解。这项研究的重点是2023年6月加拿大野火中WFPM的物理化学特征，该野火影响了美国东北部的1亿多人。特别是在新泽西/纽约。在为期3天的事件中，部署了气溶胶系统来表征WFPM，揭示了前所未有的质量浓度，主要是在WFPM0.1和WFPM0.1-2.5级分中。WFPM2.5峰值浓度达到317μg/m3，是国家环境空气质量标准（NAAQS）24小时平均限值的近10倍。化学分析显示有机碳与总碳之比很高(96%)，与棕色碳野火纳米颗粒一致。发现高浓度的高分子量PAHs主要与WFPM0.1结合，生物质燃烧的分子标记和已知的致畸剂，是最丰富的（>70％）。计算模型估计72小时内肺总沉积为9.15mg，强调WFPM的健康风险，特别是由于其长途旅行能力和对人口稠密地区的影响。
