Characteristics of PM 10 levels monitored for more than a decade in 1 subway stations in South Korea 2 3

1 Characteristics of PM10 levels monitored for more than a decade in 1 subway stations in South Korea 2 3 Sangjun Choi1, Ju-Hyun Park2, Seo-Yeon Bae3, So-Yeon Kim3, Hyaejeong 4 Byun4, Hyunseok Kwak5, Sungho Hwang6, Jihoon Park7, Hyunhee Park8, 5 Kyong-Hui Lee9, Won Kim10, Dong-Uk Park3 6 7 1 Department of Occupational Health, Daegu Catholic University, Gyeongsangbuk-do, Republic 8 of Korea 38430, 2 Department of Statistics, Dongguk University, Seoul, Republic of Korea 04620, 9 3 Department of Environmental Health, Korea National Open University, Seoul, Republic of 10 Korea 03087, 4 Samsung SDS CO., LTD., Seoul, Republic of Korea 05510, 5 Occupational Lung 11 Diseases Institute, Korea Workers’ Compensation and Welfare Service, Incheon, Republic of 12 Korea 21417, 6 National Cancer Control Institute, National Cancer Center, Goyang, Republic of 13 Korea 10408, 7 Institute of Health and Environment, Seoul National University, Seoul, Republic 14 of Korea 08826, 8 Occupational Safety and Health Research Institute, Ulsan, Republic of Korea 15 44429, 9 Force Health Protection & Preventive Medicine, MEDDAC-Korea, US Army, 10 Wonjin 16 Institute of Occupational and Environmental Health, Seoul, Republic of Korea 02221 17 18 Abstract 19 20 This study aimed to evaluate the variation in PM10 in the subways over the past years in Korea 21 and to identify factors influencing the PM10 level. The PM10 measured internally by subway 22 companies according to legal requirements was categorized by subway characteristics. These 23 were statistically examined using a mixed effect model to identify the parameters influencing 24 PM10 level. The PM10 levels monitored near platforms or waiting rooms ranged from 53.9 to 92.4 25 μg m-3 and were all below the 150 μg m-3 which is a regulatory standard. PM10 levels monitored 26 on platforms were found to far exceed the yearly average atmospheric environmental standard 27 (50 μg m-3). Based on both univariate and multiple analyses, several subway characteristics, 28 including the presence of a platform screen doors (PSD), were found to be significantly 29 associated with PM10 level, though there is little difference in significant factors among cities. 30 Particularly, stations without transfer lines and the presence of PSD contributed to reduction in 31 the PM10 level at the platform, except for Busan and in specific years. 32 33