Phenol Reactions in Aqueous Particles as a Source of Secondary Organic Aerosol

已经确定，野火和生物质燃烧会排放直接危害人类健康的颗粒物。最近人们认识到，燃烧木材排放的反应性气体也会转化为颗粒，这种间接产生的颗粒会加剧人类的暴露问题。这项工作将研究火灾羽流中的关键反应气体在实验室和现场反应的机制，以量化间接产生的颗粒物并估计其对人体暴露的影响。这项研究建立在最近的实验室工作的基础上，即生物质燃烧大量排放的酚可以通过云和雾中的反应提供大量二次颗粒物来源，因为酚相对容易分配到水相。然而，由于火灾羽流老化过程中半挥发性气体的稀释和蒸发的影响，在现场还没有观察到二次粒子增强。该项目将调查是否以及如何将生物质燃烧废液中大量存在的活性气体--目标酚--转化为颗粒。这项研究将在实验室和现场分离和测量基本过程，并将它们结合起来，以阐明苯酚转化为颗粒的机理。这一结果将改进对火灾羽流中二次粒子形成对人体暴露贡献的评估。

It is established that wildfires and biomass burning emit particles directly that harm human health. It has recently been recognized that reactive gases emitted by burning wood can also convert to particles, and this indirect particle production would exacerbate the exposure problem for humans. The work will investigate the mechanisms by which key reactive gases in fire plumes react in the laboratory and field to quantify the indirect production of particles and estimate its impacts on human exposure.This research builds on recent laboratory work that phenols emitted by biomass burning in large amounts could provide a large source of secondary particles via reactions in cloud and fog drops since the phenols partition into the aqueous phase relatively easily. However, secondary particle enhancement has not yet been observed in the field presumably due to the effects of dilution and evaporation of semi-volatile gases during aging of fire plumes. The project will investigate if and how targeted phenols that are reactive gases present in significant amounts in biomass burning effluents can be converted to particles. The research will isolate and measure the fundamental processes in the laboratory and field and integrate them to elucidate the mechanism of phenol to particle conversion. The results will improve the assessment of the contributions of secondary particle formation in fire plumes to human exposure.