Analysis of the National Air Pollutant Emissions Inventory (CAPSS 2018) Data and Assessment of Emissions Based on Air Quality Modeling in the Republic of Korea

According to the 2018 National Air Pollutant Emissions Inventory (NEI), air pollutant emissions in the Republic of Korea comprised 808,801 tons of CO, 1,153,265 tons of NO_X, 300,979 tons of SO_X, 617,481 tons of TSP, 232,993 tons of PM₁₀, 98,388 tons of PM_2.5, 15,562 tons of black carbon (BC), 1,035,636 tons of VOCs, and 315,975 tons of NH₃. As for national emission contributions to primary PM_2.5 and PM precursors (NO_X, SO_X, VOCs, and NH₃), major source categories were the road sector for NO_X, the industry sector for SO_X and PM_2.5, and the everyday activities and others sector for VOCs and NH₃. In the case of emissions by region, the largest amount of NO_X was emitted from the Seoul Metropolitan Areas (SMA; Seoul, Incheon, and Gyeonggi-do, hereafter SMA) and the largest amounts of SO_X, PM_2.5, VOCs, and NH₃ were from the Yeongnam region. A 3D chemical transport modeling system was used to examine the uncertainty of the national air pollutant emissions based on the National Emission and Air Quality Assessment System (NEAS). Air quality was simulated using CAPSS 2018, and the simulation data were compared with observed concentrations to examine the uncertainties of the current emissions. These data show that emissions from five si (cities) (Pohang, Yeosu, Gwangyang, Dangjin, and Ulsan) need to be improved. Most of all, it is necessary to examine the emissions from places of business that use anthracite, which is the major PM_2.5 emission source, as fuel in these areas.