Bruns Emily A, El Haddad Imad, Slowik Jay G, Kilic Dogushan, Klein Felix, Baltensperger Urs, Prévôt André S H
Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland.
Sci Rep. 2016 Jun 17;6:27881. doi: 10.1038/srep27881.
Organic gases undergoing conversion to form secondary organic aerosol (SOA) during atmospheric aging are largely unidentified, particularly in regions influenced by anthropogenic emissions. SOA dominates the atmospheric organic aerosol burden and this knowledge gap contributes to uncertainties in aerosol effects on climate and human health. Here we characterize primary and aged emissions from residential wood combustion using high resolution mass spectrometry to identify SOA precursors. We determine that SOA precursors traditionally included in models account for only ~3-27% of the observed SOA, whereas for the first time we explain ~84-116% of the SOA by inclusion of non-traditional precursors. Although hundreds of organic gases are emitted during wood combustion, SOA is dominated by the aging products of only 22 compounds. In some cases, oxidation products of phenol, naphthalene and benzene alone comprise up to ~80% of the observed SOA. Identifying the main precursors responsible for SOA formation enables improved model parameterizations and SOA mitigation strategies in regions impacted by residential wood combustion, more productive targets for ambient monitoring programs and future laboratories studies, and links between direct emissions and SOA impacts on climate and health in these regions.
在大气老化过程中转化形成二次有机气溶胶（SOA）的有机气体大多尚未明确，尤其是在受人为排放影响的地区。SOA主导着大气有机气溶胶负荷，而这一知识空白导致了气溶胶对气候和人类健康影响的不确定性。在此，我们利用高分辨率质谱对住宅木材燃烧产生的一次排放和老化排放进行表征，以识别SOA前体。我们确定，传统模型中包含的SOA前体仅占观测到的SOA的约3 - 27%，而我们首次通过纳入非传统前体解释了约84 - 116%的SOA。尽管木材燃烧过程中会排放数百种有机气体，但SOA主要由仅22种化合物的老化产物构成。在某些情况下，仅苯酚、萘和苯的氧化产物就占观测到的SOA的约80%。确定导致SOA形成的主要前体，有助于改进受住宅木材燃烧影响地区的模型参数化和SOA缓解策略，为环境监测计划和未来实验室研究提供更有针对性的目标，并建立这些地区直接排放与SOA对气候和健康影响之间的联系。
