Characterization of a High PM_2.5 Exposure Group in Seoul Using the Korea Simulation Exposure Model for PM_2.5 (KoSEM-PM) Based on Time–Activity Patterns and Microenvironmental Measurements

The Korea Simulation Exposure Model for fine particulate matter (PM2.5) (KoSEM-PM) was developed to estimate population PM2.5 exposure in Korea. The data were acquired based on 59,945 min of the actual microenvironmental PM2.5 measurements and on the time⁻activity patterns of 8072 residents of Seoul. The aims of the study were to estimate daily PM2.5 exposure of Seoul population, and to determine the characteristics of a high exposure group. KoSEM-PM estimated population exposures by applying the PM2.5 distribution to the matching time⁻activity patterns at 10-min intervals. The mean personal PM2.5 exposure level of the surveyed subjects in Seoul was 26.0 ± 2.7 µg/m3 (range: 21.0⁻40.2 µg/m3) in summer. Factors significantly associated with high exposure included day of the week, age, industry sector, job type, and working hours. Individuals surveyed on Saturdays were more likely to be in the high exposure group than those surveyed on weekdays and Sundays. Younger, non-office-working individuals with longer working hours were more likely to be in the high exposure group. KoSEM-PM could be a useful tool to estimate population exposure levels to other region in Korea; to expand its use, microenvironmental measurements are required for other region in Korea