Source Apportionment of Anthropogenic Secondary Organic Aerosol

二次有机气溶胶(SOA)是大气中初级(挥发性；VOC)有机化合物氧化形成的细小颗粒。二次有机气溶胶的来源既有天然来源(如植物)，也有人为来源(如汽车尾气排放中未燃烧的碳氢化合物)。源解析研究通过提高我们对细颗粒物来源的理解而使社会受益，细颗粒物已被证明与过量发病率相关，并且存在于我们呼吸的空气中。这项研究项目的科学目标将确定人为的SOA源特征，以及它们对城市地区细颗粒物浓度(PM2.5；小于2.5微米的颗粒物)相对于生物来源和其他来源的影响。一种基于现场的方法将在许多城市地点进行环境气溶胶采样：休斯顿、德克萨斯州、亚特兰大、佐治亚州、密尔沃基、威斯康星州。在这些地点，先前的研究已经确定了大气中人为挥发性有机化合物(VOC)和生物来源化合物的混合负荷，从而可以估计它们对SOA形成的各自贡献。造成PM2.5等污染物达到危险标准水平的人为活动需要加以确定，并准确量化到来源水平，然后才能明智地成为旨在降低环境中细颗粒物水平的管制或缓解的目标。这项研究中使用的方法主要是分析芳香族挥发性有机化合物的光氧化产物芳香族磺酸盐，作为人为输入SOA的化学示踪剂。

Secondary organic aerosols (SOA) are fine particles that arise from the oxidation of primary (volatile; VOC) organic compounds in the atmosphere. Secondary organic aerosols can have source contributions from both natural (e.g. from plants) and man-made (e.g. from unburnt hydrocarbons in automotive tailpipe emissions) sources. Source apportionment studies benefit society by improving our understanding of the sources of fine particulate matter, which has been shown to be correlated with excess morbidity, and is present in the air we breathe The science objectives of this research project will determine the anthropogenic SOA source characteristics, and their impact on fine particle concentrations (PM2.5; particulate matter less than 2.5microns) in urban areas relative to biogenic and other sources. A field-based approach will target ambient aerosol sampling at a number of urban locations: Houston, TX, Atlanta, GA, Milwaukee, WI. These are all sites where prior studies have established a mix of atmospheric loadings of anthropogenic volatile organic compounds (VOC) and biogenic compounds, allowing their respective contribution to SOA formation to be estimated. Anthropogenic activities that contribute to dangerous levels of criteria pollutants such as PM2.5 need to be identified and accurately quantified to source level before they can sensibly become targets of regulation or mitigation aimed at reducing ambient levels of fine particles. The approach used in this study centers on analysis of aromatic sulfonates, photoxidation products from aromatic VOCs, as chemical tracers of anthropogenic inputs into SOA.