O'Malley Kelly E, Ghetu Christine C, Rohlman Diana, Anderson Kim A
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States.
College of Health, Oregon State University, Corvallis, Oregon 97331, United States.
Environ Sci Technol. 2024 Dec 31;58(52):23117-23126. doi: 10.1021/acs.est.4c09139. Epub 2024 Dec 17.
The global wildfire risk is predicted to rise due to contributing factors of historical fire management strategies and increases in extreme weather conditions. Thus, there is a need to better understand contaminant movement and human exposure to wildfire smoke. Vapor-phase polycyclic aromatic hydrocarbons (PAHs) are elevated during wildfires, but little is known about how these chemicals move during and after wildfire events for exposure risk assessment. Paired air and soil pore air passive samplers were deployed before, during, and after wildfires to determine diffusive flux of vapor-phase parent (p-PAH) and alkylated (a-PAH) PAHs in the Western United States. Naphthalene and 2-methylnaphthalene contributed to most of the volatilization and deposition (6.3-89%) before and after a wildfire. Retene (41%) and phenanthrene (27%) contributed substantially to deposition during a wildfire. During wildfires, the number of PAHs in deposition increased at sites with worse air quality. Most p-PAHs and a-PAHs were either depositing or near equilibrium after a wildfire, except for retene at several locations. A majority (≥50%) of PAHs had a 50% magnitude difference between flux before and after a wildfire. This study increases the understanding of PAH movement and exposure during each stage of the wildfire cycle.
由于历史火灾管理策略和极端天气状况增加等促成因素，预计全球野火风险将会上升。因此，有必要更好地了解污染物的迁移以及人类接触野火烟雾的情况。气相多环芳烃（PAHs）在野火期间会增加，但对于这些化学物质在野火事件期间及之后如何迁移以进行暴露风险评估，人们了解甚少。在美国西部，在野火发生之前、期间和之后部署了成对的空气和土壤孔隙空气被动采样器，以确定气相母体（p-PAH）和烷基化（a-PAH）多环芳烃的扩散通量。萘和2-甲基萘在野火前后的挥发和沉积中占大部分（6.3-89%）。惹烯（41%）和菲（27%）在野火期间对沉积有很大贡献。在野火期间，空气质量较差的地点沉积中的多环芳烃数量增加。野火过后，除了几个地点的惹烯外，大多数p-PAHs和a-PAHs要么在沉积，要么接近平衡状态。大多数（≥50%）多环芳烃在野火前后的通量有50%的量级差异。这项研究增进了对野火周期各阶段多环芳烃迁移和暴露情况的了解。
