Indoor Air Pollutants Concentration in a Seoul Metropolitan Underground Railway Station

The objective of this study was to explore the characteristics of concentration of indoor air pollutants, such as PM10, CO2, and NO2, measured by tele-monitoring system in a Seoul Metropolitan underground railway station from January 1, 2008 to December 31, 2012. The annual average concentration of indoor air pollutants actually varied over a wide range and was found to exhibit marked variation with time and measurement sites (tunnel inlet, platform, and concourse). After installing platform screen doors, the average PM10 concentration on platform and concourse was decreased by 43.8 % and 31.2%, respectively during the study periods. The relationship between the concentration of PM10 and meteorological parameters (relative humidity and rainfall) or the Asian dust events was regarded as statistically significant. The correlations between the number of boarding/alighting passengers and PM10, CO2, and NO2 were calculated. A p-value of less than 0.01 was regarded as significant except NO2. The I/O ratio of PM10 concentration was elevated after a congested time (about 08:00 am). The average I/O ratios of NO2 were observ-ed in concourse and platform on 03:00 am with 1.76±0.91 and 1.50±0.51, respectively. The average daily variation of standard excess rate of PM10 and NO2 concentration in concourse and platform was investigated. The highes