| Title: | Abundant oxygenated volatile organic compounds and their contribution to photochemical pollution in subtropical Hong Kong |
| Author(s): | Hui L; Feng X; Yuan Q; Chen Y; Xu Y; Zheng P; Lee S; Wang Z; |
| Address: | "Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong SAR, 999077, China. Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, 999077, China. Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong SAR, 999077, China. Electronic address: z.wang@ust.hk" |
| DOI: | 10.1016/j.envpol.2023.122287 |
| ISSN/ISBN: | 1873-6424 (Electronic) 0269-7491 (Linking) |
| Abstract: | "Volatile organic compounds (VOCs), which are ubiquitous pollutants in the urban and regional atmosphere, promote the formation of ozone (O(3)) and secondary organic aerosols, thereby significantly affecting the air quality and human health. The ambient VOCs at a coastal suburban site in Hong Kong were continuously measured using proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) from November 2020 to December 2020. 83 VOC species, including 23 C(x)H(y), 53 C(x)H(y)O(1-3), and 7 nitrogen-containing species, were measured during the campaign, with a mean concentration of 36.75 ppb. Oxygenated VOCs (OVOCs) accounted for most (77.4%) of the measured species, including C(x)H(y)O(1) (50.7%) and C(x)H(y)O(2) (25.1%). The measured VOC species exhibited distinct temporal and diurnal variations. High concentrations of isoprene and OVOCs were measured in autumn with more active photochemistry, whereas large evening peaks of aromatics from local and regional primary emissions were prominent in winter. The OH reactivity and O(3) formation potential (OFP) of key precursors were quantified. OVOCs contributed about half of the total OH reactivity and OFP, followed by alkenes and aromatics, and the contribution of aromatics increased significantly in winter. The potential source contribution function was used to investigate the potential source regions associated with high VOC concentrations. Through positive matrix factorization analysis, six major sources were identified based on fingerprint molecules. The contributions of biogenic sources and secondary formation to the observed species were notable in late autumn, whereas vehicle emissions and solid fuel combustion had higher contributions in winter. The findings highlight the important role of OVOCs in photochemical pollution and provide valuable insights for the development of effective pollution control strategies" |
| Keywords: | Humans Hong Kong *Volatile Organic Compounds/analysis *Air Pollutants/analysis Environmental Monitoring Vehicle Emissions/analysis *Ozone/analysis China O(3) formation potential Oxygenated VOCs PTR-ToF-MS Source apportionment Volatile organic compounds; |
| Notes: | "MedlineHui, Lirong Feng, Xin Yuan, Qi Chen, Yi Xu, Yang Zheng, Penggang Lee, Shuncheng Wang, Zhe eng England 2023/08/11 Environ Pollut. 2023 Oct 15; 335:122287. doi: 10.1016/j.envpol.2023.122287. Epub 2023 Aug 8" |
