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Lee G, Ahn J, Park SM, Moon J, Park R, Sim MS, Choi H, Park J, Ahn JY. Sulfur isotope-based source apportionment and control mechanisms of PM 2.5 sulfate in Seoul, South Korea during winter and early spring (2017-2020). Sci Total Environ 2023; 905:167112. [PMID: 37717778 DOI: 10.1016/j.scitotenv.2023.167112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 09/19/2023]
Abstract
High level of particulate matter (PM) concentrations are a major environmental concern in Seoul, South Korea, especially during winter and early spring. Sulfate is a major component of PM and induces severe environmental pollution, such as acid precipitation. Previous studies have used numerical models to constrain the relative contributions of domestic and trans-boundary sources to PM2.5 sulfate concentration in South Korea. Because of the scarce measurement result of δ34S for PM2.5 sulfate in South Korea, poorly defined δ34S value of domestic sulfur sources, and no application of sulfur isotope fractionation during sulfate formation in previous observation-based studies, source apportionment results conducted by model studies have not been corroborated from independent chemical observations. Here, we examined the δ34S of PM2.5 in Seoul and domestic sulfur sources, and considered the sulfur isotope fractionation for accurate source apportionment constraint. Accordingly, domestic and trans-boundary sulfur sources accounted for approximately (16-32) % and (68-84) % of the sulfate aerosols in Seoul, respectively, throughout the winter and early spring of 2017-2020. Air masses passing through north-eastern China had relatively low sulfate concentrations, enriched δ34S, and a low domestic source contribution. Those passing through south-eastern China had relatively a high sulfate concentrations, depleted δ34S, and high domestic source contribution. Furthermore, elevated PM2.5 sulfate concentrations (>10 μg m-3) were exclusively associated with a weak westerly wind speed of <3 m s-1. From December 2019 to March 2020, Seoul experienced relatively low levels of PM2.5 sulfate, which might be attributed to favorable weather conditions rather than the effects of COVID-19 containment measures. Our results demonstrate the potential use of δ34S for accurate source apportionment and for identifying the crucial role of regional air mass transport and meteorological conditions in PM2.5 sulfate concentration. Furthermore, the data provided can be essential for relevant studies and policy-making in East Asia.
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Affiliation(s)
- Giyoon Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, South Korea
| | - Jinho Ahn
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, South Korea.
| | - Seung-Myung Park
- Air Quality Research Division, National Institute of Environmental Research, Seo, Incheon 22689, South Korea
| | - Jonghan Moon
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, South Korea
| | - Rokjin Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, South Korea
| | - Min Sub Sim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, South Korea
| | - Hanna Choi
- Climate Change Response Division, Korea Institute of Geoscience and Mineral Resources, Gwahak-ro 124, Yuseong-gu, Daejeon 34132, South Korea
| | - Jinsoo Park
- Air Quality Research Division, National Institute of Environmental Research, Seo, Incheon 22689, South Korea
| | - Joon-Young Ahn
- Air Quality Research Division, National Institute of Environmental Research, Seo, Incheon 22689, South Korea
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