Analysis of the National Air Pollutant Emissions Inventory (2022) in the Republic of Korea

The Republic of Korea estimates annual air pollutant emissions through the Clean Air Policy Support System (CAPSS), based on 260 types of basic data collected from approximately 150 institutions. These estimation results are published annually as national statistics and are used to formulate and evaluate national air quality policies. This study analyzed the emission characteristics by source type and administrative region using the 2022 Republic of Korea National Air Pollutant Emissions Inventory (NEI). The results were further categorized according to improvements compared with 2021—specifically in estimation methods, emission factors, policies, and socioeconomic conditions. In 2022, national emissions of major air pollutants were as follows: PM₂.₅, 59,459 tons; SOₓ, 126,743 tons; NOₓ, 857,026 tons; VOCs, 938,341 tons; NH₃, 242,227 tons; and CO, 921,783 tons. The primary emission sources for each pollutant were: fugitive dust for PM₂.₅ (26.1%), combustion in the manufacturing industry for SOₓ (32.4%), non-road transport for NOₓ (31.8%), solvents use for VOCs (54.9%), agriculture for NH₃ (83.6%), and biomass burning for CO (24.0%). Compared with 2021 levels, emissions of PM₂.₅ and CO increased by 2,142 tons (3.7%) and 226,966 tons (32.7%), respectively, while emissions of SOₓ, NOₓ, VOCs, and NH₃ decreased by 34,250 tons (21.3%), 27,427 tons (3.1%), 64,469 tons (6.4%), and 19,781 tons (7.5%), respectively. These fluctuations were primarily attributed to varying influencing factors: PM₂.₅ and NOₓ were strongly affected by socioeconomic activities and policy implementation, respectively, whereas changes in SOₓ, VOCs, NH₃, and CO were mainly driven by emission reduction improvements.