Jihwan Son1,2, Kwangrae Kim1, Seungmi Kwon1, Seung-Myung Park2, Kwangtae Ha1, Yunmi Shin1, Mijin Ahn1, Seogju Cho1, Jinho Shin1, Yongseung Shin1, Gangwoong Lee This email address is being protected from spambots. You need JavaScript enabled to view it.2 

1 Seoul Metropolitan Government Research Institute of Public Health and Environment, Gwacheon, Gyeonggi 13818, Korea
2 Department of Environmental Science, Hankuk University of Foreign Studies, Yongin, Gyeonggi 17035, Korea

Received: September 27, 2020
Revised: January 17, 2021
Accepted: February 25, 2021

 Copyright The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited.

Download Citation: ||https://doi.org/10.4209/aaqr.200573  

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Cite this article:

Son, J., Kim, K., Kwon, S., Park, S.M., Ha, K., Shin, Y., Ahn, M., Cho, S., Shin, J., Shin, Y., Lee, G. (2021). Source Quantification of PM10 and PM2.5 Using Iron Tracer Mass Balance in a Seoul Subway Station, South Korea. Aerosol Air Qual. Res. 21, 200573. https://doi.org/10.4209/aaqr.200573


  • We measured PM and heavy metal compositions in subway station sectors.
  • PM behaviours were modelled with mass balance of PM mass and its iron content.
  • Controlling PM from tunnel is the most effective way to reduce PM in subway station.


In this study, we simultaneously measured the PM10 and PM2.5 mass concentrations and their heavy metal content for three days at a subway station in Seoul to investigate the airborne PM flows. The average concentrations were 59 µg m–3, 37 µg m–3, 111 µg m–3, and 369 µg m–3 for the PM10 and 43 µg m–3, 28 µg m–3, 58 µg m–3, and 132 µg m–3 for the PM2.5 at the outdoor air inlet, in the concourse, on the platform, and in the tunnel, respectively. We also found strong correlations between the temporal variations at adjacent sampling locations for both fractions, although they were higher for the PM2.5. Additionally, of the airborne trace metals detected at the sampling locations inside the station (the concourse, platform, and tunnel), iron (Fe) displayed the highest concentration and was thus selected as a tracer of PM. Applying a simple mass balance model to the Fe concentrations and ventilation rates revealed that 78% of the PM10 and 62% of the PM2.5 on the platform emanated from the tunnel, whereas 84% of the PM10 and 87% of the PM2.5 in the concourse originated outdoors (and arrived in the filtered air). These results further confirm that reducing PM emission from the tunnel is the most effective strategy for improving air quality on the platform and achieving compliance with the national guideline.

Keywords: Subway, Mass balance model, Air quality, Particle matter, Heavy metal


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