KTX 객실의 CO₂ 농도와 승객 수 및 터널구간과의 상관관계

With increasing concerns of indoor air quality, CO₂ concentration in the public transportation, such as train, bus, and subway, draws big interests. The CO₂ concentration in the indoor air is regarded as index of ventilation status rather than that of adverse health effect. In this study, we measured the time-series of CO₂ concentrations in the KTX cabin during the journey of Gyongbu-line (Seoul-Busan) and Honam-line (Seoul-Mokpo) with the number of passengers on board. At the same time, the concentration of particulate matter (PM), temperature, humidity and gaseous pollutants including HCHO and VOCs were monitored. It is found that the CO₂ concentration was correlated linearly with number of passengers and was highly correlated with tunnel regions where the ventilation unit (flap) was closed.