서울시 지하철 역사의 라돈농도분포 조사

Distribution of Radon Concentration at Subway Stationin Seoul

The radon concentrations were measured to survey distribution of radon concentrations in Seoul subway stations. The radon concentrations in air and water were measured at seventeen subway stations(Mapo, Chungjongno, Sodaemun, Kwanghwamun, Chongno3ga, Ulchiro4ga, Tangdaemun, Sangildong on Line 5;Nowon, Chunggye, Hagye, Kongnung, Taenung, Mokkol, Chunghwa, Sangbong, Myomok on Line 7) using the RAdtrakTM radon gas detector, Pylon AB-5 continuous passive radon detector and liquid scintillation counting method from January to May 1999. The major results obtained from this study were as follows: The long-term mean concentrations of radon were 61.8 Bq/m3 in office, 78.9 Bq/m3 in platform, 38.2 Bq/m3 in concourse and 20.1 Bq/m3 in outdoor, respectively. These levels were less than the action level (148 Bq/m3) of the U.S. EPA. The highest level of short-term mean concentrations was 116.55 Bq/m3 at Chongno3ga station on the 5th line subway stations, while the lowest mean concentration was 19.55 Bq/m3 at Mokkol station on the 7th line subway stations. The highest concentration of radon in the road water and storing underground water in the subway stations was 234.7 KBq/m3 and 155.5 KBq/m3 in Sodaemun subway station, respectively. The results suggest that radon concentration in subway stations seems to be affected by ventilation and radon concentratin in underground water in the subway stations.