This study aimed to assess the pollution level in 13 crowded subway stations in an effort to understand the spatial and seasonal factors of Indoor Air Quality. The main measured items were particulate pollutants such as PM10 and PM2.5 and gaseous pollutants such as CO2, HCHO, Rn, TVOC, BTEX, and Styrene at concourses and platforms in the summer and winter periods. The influence of the draught created by the movement of the train was classified into lateral and island platforms, and the concentrations of PM by location (entrance, middle, and end) were statistically compared and analyzed. As a result, the concentrations of PM were confirmed high in the order of Platform > Concourse > Ambient air. In particular, in the case of platform PM10, the frequency exceeding the standard value (100 μg/m3) was 38.5% and the maximum concentration was 196.2 μg/m3. All gaseous pollutants were at lower levels than the standard, and the factors affecting CO2 and Rn were identified as the number of users and geological characteristics, respectively. The principal component analysis (PCA) demonstrated that PM was found to be a major indicator of the air quality management of subway stations. In particular, the concentrations at entrance and end areas in the lateral platform were about 1.4 times higher with regard to PM10 than in the middle area, and about 1.9 times higher with regard to PM2.5 due to the effect created by the draught produced by the movement of the train. Therefore, in order to manage PM in the platform area, a specialized management plan for places with particularly high PM concentration within the platform area is required. In addition, it is necessary to evaluate the effect created by the draught produced by train movement when selecting locations for measuring indoor air quality.

This study was performed to investigate the distribution of indoor air pollutants in medical facility in Gyeonggi-do area from February to November, 2012, and to conduct the health risk assessment from obtained data. PM10, CO₂, formaldehyde, CO, and total bacteria count(TBC) did not exceed the maintained standards, but mean concentration of TVOC was 402.3 ㎍/㎥ and thirteen of them exceeded the recommended standard. In the concentration distribution of pollutants for the monthly samples, CO₂, formaldehyde, TVOC, TBC were the highest level in August. From the factor analysis of indoor air pollution provided three factors; the first factor was seasonal factor (indoor temperature and humidity, TBC and formaldehyde), the second factor was ventilation factor (CO₂, PM10 and CO), and the third factor was building(or interior) factor (TVOCs). In the health risk assessment results, the excess carcinogenesis of formaldehyde for resonable maximum exposure worker was 1.21×10-⁴ which means exceeding the cancer criteria(1.0×10-⁴). We confirmed the probability of health effect caused by TVOC. The lifetime excess cancer risk of carcinogens(benzene, formaldehyde) and hazard quotient of non-carcinogens(toluene, ethylbenzene, xylene, styrene), and risk of regulation substances(PM10, CO₂) were safety level for inpatients and out patients.