| Literature DB >> 33593919 |
Junfeng Wang1,2, Jianhuai Ye2, Qi Zhang3, Jian Zhao4, Yangzhou Wu5, Jingyi Li1, Dantong Liu5, Weijun Li5, Yange Zhang6, Cheng Wu7, Conghui Xie4, Yiming Qin2, Yali Lei2, Xiangpeng Huang1, Jianping Guo8, Pengfei Liu9, Pingqing Fu10, Yongjie Li11, Hyun Chul Lee12, Hyoungwoo Choi12, Jie Zhang13, Hong Liao1, Mindong Chen1, Yele Sun4, Xinlei Ge14, Scot T Martin2, Daniel J Jacob15.
Abstract
Secondary organic aerosol (SOA) produced by atmospheric oxidation of primary emitted precursors is a major contributor to fine particulate matter (PM2.5) air pollution worldwide. Observations during winter haze pollution episodes in urban China show that most of this SOA originates from fossil-fuel combustion but the chemical mechanisms involved are unclear. Here we report field observations in a Beijing winter haze event that reveal fast aqueous-phase conversion of fossil-fuel primary organic aerosol (POA) to SOA at high relative humidity. Analyses of aerosol mass spectra and elemental ratios indicate that ring-breaking oxidation of POA aromatic species, leading to functionalization as carbonyls and carboxylic acids, may serve as the dominant mechanism for this SOA formation. A POA origin for SOA could explain why SOA has been decreasing over the 2013-2018 period in response to POA emission controls even as emissions of volatile organic compounds (VOCs) have remained flat.Entities:
Keywords: aqueous-phase oxidation; fossil-fuel combustion emissions; polycyclic aromatic hydrocarbons; secondary organic aerosol
Year: 2021 PMID： 33593919 PMCID： PMC7923588 DOI： 10.1073/pnas.2022179118
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205