Identification of Fine Dust in Schools through Comprehensive Chemical Characterization

Abstract

The objective of this study was to analyze the temporal and spatial characteristics of fine particulate matters by using huge hourly datasets of PM 2.5 , including chemical information monitored at the 6 national intensive monitoring sites (NIMSs) from 2013 to 2018 in Korea. Hourly PM 2.5 raw datasets were obtained from the National Institute of Environmental Research (NIER) in Korea. Monitoring sites included urban, rural/agricultural, industrial, and marine environments. Since the PM 2.5 concentration steadily decreased nationwide, each species concentration also decreased in general. One of key reasons for decreasing PM 2.5 might be explained by the implementation of domestic fine dust reduction policies and external influences such as PM 2.5 concentration reduction in China. It was observed that 45.0% of all datasets for 6 years were classified as good condition. The average sum of 14 elements over all sites in 2018 was calculated to be 501.5 ng/m 3 , and its mass ratio for PM 2.5 (21.9 μg/m 3 ) was 2.30%. The inorganic elements were generally higher in industrial/urban areas than in agricultural areas. In addition, the average TC (total carbon) over all 6 sites was 28.3% of PM 2.5 with the range of 23.6% to 31.4%. The TC in small urban areas was much higher than that in marine areas or even that in large, populated urban area/industrial areas. It seemed that the latter areas were better controlled than the former area in terms of combustion activities of fossil fuels. It is suggested that these results could be play an important role as important basic data to manage ambient air quality and establish effective emission reduction strategies in each region.

Effects of the Corona Pandemic on Indoor Fine Dust in Urban Schools

“…The decrease of PM2.5 was more obvious than PM10, probably because reduction of industrial activities might release less precursors for condensable particulate matters (CPM) such as nitrates, sulfates and VOCs as well as primary fine particulate matters. These secondary aerosols in general account for about 50% to 60 % of urban atmospheric PM2.5 [10,11]. Thus, while PM10 in 2021 showed a recovery compared to 2020, when a strict policy of exclusive lock-down took place, PM2.5 continued to reveal a declining tendency.…”