우리나라 배경지역에서 분진의 기간별 분석, 미측정 PM2.5 자료의 추정 및 COVID-19의 영향평가

Abstract

Hourly datasets of PM10 and PM2.5 during the period of 2015 to 2020 were obtained from the 3 national background monitoring stations (NBMSs) at the Baengnyeong (NBMS-B), the Ulleung (NBMS-U), and the Jeju Islands (NBMS-J) in Korea. In this study, the temporal behaviors of PM10, PM2.5, and F/C ratio (fine/coarse ratio) were intensively analyzed and interpreted with supplementary information such as wind direction, amount of precipitation, and yellow storm frequency. The first 5-year whole datasets excluding the year of 2020 were statistically interpreted to investigate temporal variation and characterization of PM after categorizing the datasets by periodical time bases such as year, month, season, day of the week, and hour. At the NBMS-B, NBMS-U, and NBMS-J, 5-year average PM 10 levels were 41.8 mu g/m(3), 40.9 mu g/m(3), and 41.7 mu g/m(3) respectively and those for PM2.5 were 21.3 mu g/m(3), 17.5 mu g/m(3), and 19.8 mu g/m(3) respectively. The PM10 and PM2.5 levels were significantly exceeding the WHO guidelines. We have built the DB of temporal F/C ratios to estimate the unknown PM2.5 data before the year of 2015. In case of expanding the methodology to all monitoring stations nationwide near future, the estimated PM2.5 datasets can be used to build the new emission inventory for the unknown PM2.5 emissions in past.This study also performed to compare the ambient air quality before and after COVID-19 pandemic. At the NBMS-B, NBMS-U, and NBMS-J, 5-year average PM10 levels were decreased by 17.8%, 44.4%, and 26.7% respectively due to the outbreak of COVID-19. Likewise, PM2.5 levels were decreased by 11.2%, 30.3%, and 23.4% respectively. Particularly high F/C ratios at the all NBMSs were observed in Jan, Feb, and Aug during the pandemic period due to marked PM10 decrease caused by pervading earlier COVID-19 fear mood in Jan and Feb as well as shrinking tourism industry in Aug.