Airborne Radon Exposure in Seoul Subway Korea

Radon, as the heaviest radioactive gas, can accumulate in confined areas such as underground subway stations
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Subway Workers' Exposure to Radon in Korea

Sangjun Choi (1) , Seongmin Lee (2) , Sanghyuk Yim (2)
1. Department of Occupational Health, Catholic University of Daegu, Korea
2. Wonjin Institute for Occupational and Environmental Health, Korea

This presentation was available to view as a discussion poster at the 7th International Conference on the Science of Exposure Assessment – X2012. It was presented on 04 July 2012 from 09.30 – 11.45 am followed by a chaired discussion of all posters in this session on Chemicals in the Workplace.

The purpose of this study is to investigate the relationship between the levels of radon in air and environmental conditions in the underground, and to develop the management strategies for the protection of the subway workers.

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Radon in the Underground Workplaces

Radon in the Underground Workplaces; Assessment of the Annual Effective Dose due to Inhaled Radon for the Seoul Subway Station Staffs

* University of Science and Technology, † Korea Institute of Nuclear Safety, ‡ Korea Research Institute of Standards and Science
Publication December 14, 2010

The effective dose of the Seoul subway staffs due to inhaled radon (222Rn) in their workplace was investigated depended on radon concentration exposed at each workplace, and working hours and working types of the staffs.

Annual average radon concentrations ranged from 16.5 to 93.0 Bq·m‐3. The staffs commonly spend 2,304 hours in the underground spaces a year. With the radon concentrations and the working hours of the staffs, estimated annual effective doses ranged from 0.23 to 0.73 mSv·y‐1.

Distributions of Airborne Radon Concentrations in Seoul Metropolitan Subway Stations

Authors: KIM YS Institute of Environmental & Industrial Medicine, Hanyang University, Seoul, Korea; KIM DS Department of Environmental Science, Kyung Hee University, Suwon, Korea; KIM S.D Department of Environmental Engineering, University of Seoul, Seoul, Korea
Publication: September, 1993

Airborne 222Rn concentrations were surveyed to observe daily and seasonal variations in the 74 subway stations in the Seoul metropolitan area. Each station built of concrete elements usually has two or three stories underground with natural and mechanical ventilation facilities. The airborne radon level was determined three times: in July and August 1989, in January 1990, and in February 1991.

Each study duration varied from 1-4 wk. The resulting distribution of annual average radon concentration in underground platforms was characterized by a geometric mean of 93 Bq m-3. Radon levels varied within a wide range from undetectable to 677 Bq m-3 in stations. In addition to the study of short- and long-term radon variation, various environmental factors having an influence on radon level were studied in order to obtain indications of the possible radon sources.

Indoor Radon Distribution of Subway Stations in a Korean Major City

Seokwon Yoon (a), Byung-Uck Chang (ab), Yongjae Kim (a), Jong-In Byun (b) Ju-Yong Yun (ab)
a: Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon, Republic of Korea
b: University of Science and Technology, Gwahak-ro 113, Yuseong-gu, 305-333 Daejeon, Republic of Korea

Publication January, 2010

The overall survey on indoor radon concentration was conducted at all subway stations in a major city, Daejeon in the central part of Korea. It was quarterly performed from September 2007 to August 2008.

The annual arithmetic mean of indoor radon concentration of all the stations was 34.1 ± 14.7 Bq m−3, and the range of values was from 9.4 to 98.2 Bq m−3. The radon concentrations in groundwater (average 31.0 ± 0.8 Bq m−3) were not significantly high in most stations, but the concentration (177.9 ± 2.3 Bq L−1) of one station was over the level of 148 Bq L−1 in drinking water proposed by U.S. EPA.

Based on indoor survey results, the approximate average of the annual effective dose by radon inhalation to the employees and passengers were 0.24 mSv y−1, and 0.02 mSv y−1, respectively. Although the effective dose based on the UNSCEAR report was potentially estimated, for more accurate assessment, the additional survey on the influence by indoor radon will be necessary.