Reduction of Particulate Matters Levels in Railway Cabins in Korea

Abstract

Objectives: High concentrations of airborne particulate matters (PM) can affect the health of passengers using public transportation. The objectives of this research were to develop a PM control system for a railway cabin and to evaluate the performance of the device under conditions of an actual journey. Methods: This study measured the concentrations of <TEX>$PM_{10}$</TEX> and <TEX>$PM_{2.5}$</TEX> simultaneously in a reference cabin and a cabin with the PM control device. Results: The average <TEX>$PM_{10}$</TEX> concentration in the reference cabin was 100 <TEX>${\mu}g/m^3$</TEX>, and the <TEX>$PM_{10}$</TEX> concentration in the cabin with the control device was 79 <TEX>${\mu}g/m^3$</TEX>. While the overall control efficiency of the control device was 15.4%, reduction was more effective for peak <TEX>$PM_{10}$</TEX> concentration. However, <TEX>$PM_{2.5}$</TEX> levels did not differ greatly between the reference cabin and the cabin with the control device. The ratio of <TEX>$PM_{2.5}$</TEX> to <TEX>$PM_{10}$</TEX> was 0.37. <TEX>$PM_{10}$</TEX> concentrations in cabins were not associated with ambient concentrations, indicating that the main sources of <TEX>$PM_{10}$</TEX> were present in cabins. Additionally, average <TEX>$CO_2$</TEX> concentration in the cabins was 1,359 ppm, less than the maximum of 2,000 ppm set out by the Korean Ministry of Environment's guideline. The <TEX>$CO_2$</TEX> concentration in cabins was significantly associated with the number of passengers: the in-cabin concentration = <TEX>$23.4{\times}N+460.2$</TEX>, where N is the number of passengers. Conclusions: Application of the PM control device can improve <TEX>$PM_{10}$</TEX> concentration, especially at peak levels but not <TEX>$PM_{2.5}$</TEX> concentration.