Physico-chemical Characteristics and Formation of Fine particles in Suburban Environment: based on the Downwind of Seoul

PM2.5 affect climate change, visibility disturbance, and deterioration of human health such as causing asthma, cancer, and cardiovascular diseases. Seoul is a megacity and densely populated, so there are various sources of pollution such as living and transportation. Yongin in Korea, the study site, is located the downwind of Seoul. Yongin is affected by PM2.5 emitted from Seoul Metropolitan Area by the west wind. During the three study periods (January 5 - 31, May 20 - June 15, October 17 - November 22, 2021), physico-chemical Characteristics of PM2.5 were observed using High Resolution-Time of Flight Aerosol Mass (Organics, Nitrate, Sulfate, Ammonium, Chloride), Particle-Into-Liquid Sampler (PILS) coupled with Ion Chromatography (NO3-, SO42-, NH4+, Cl-, Na+, Ca2+, K+, Mg2+) and Total Organic Carbon analyzer (Water soluble organic carbon), AE33 (black carbon), and Scanning Mobility Particle Sizer (particles size distribution). In addition, precursor gases were measured using gas monitors (NH3, NOx (NO, NO2)) and a homemade semi-continuous monitoring system for atmospheric HNO3. Measurement results in this study, nitrate was high in winter and autumn. In the spring, organics, O3, and HNO3 were high because the photochemical reaction was active. The decomposition of NO3- was observed due to the high temperature. This study intended to analyze the air quality characteristics of the suburbs of Seoul, focusing on the formation of nitrate and organic aerosols.

Acknowledgment: This research was supported by the FRIEND (Fine Particle Research Initiative in East Asia Considering National Differences) Project through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT(2020M3G1A1114997), and funded by the Ministry of Education (2019R1A6C1020041).