Sources and oxidative potential of water-soluble humic-like substances (HULISWS) in fine particulate matter (PM2.5) in Beijing

Yiqiu Ma, Yubo Cheng, Xinghua Qiu*, Gang Cao, Yanhua Fang, Junxia Wang, Tong Zhu, Jianzhen Yu, Di Hu*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

91 Citations (Scopus)
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Water-soluble humic-like substances (HULISWS) are a major redox-active component of ambient fine particulate matter (PM2.5); however, information on their sources and associated redox activity is limited. In this study, HULISWS mass concentration, various HULISWS species, and dithiothreitol (DTT) activity of HULISWS were quantified in PM2.5 samples collected during a 1-year period in Beijing. Strong correlation was observed between HULISWS and DTT activity; both exhibited higher levels during the heating season than during the nonheating season. Positive matrix factorization analysis of both HULISWS and DTT activity was performed. Four combustion-related sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhausts, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULISWS for the first time. Biomass burning and secondary aerosol formation were the major contributors ( > 59%) to both HULISWS and associated DTT activity throughout the year. During the nonheating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for > 70% of HULISWS and DTT activity, implying that future reduction in PM2.5 emissions from combustion activities can substantially reduce the HULISWS burden and their potential health impact in Beijing.

Original languageEnglish
Pages (from-to)5607-5617
Number of pages11
JournalAtmospheric Chemistry and Physics
Issue number8
Publication statusPublished - 24 Apr 2018

Scopus Subject Areas

  • Atmospheric Science


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