The Seoul Metropolitan Government (SMG) confirmed that the city’s PM2.5 levels for 2022 measured an average of 18 μg/m3, breaking its record low every year for three consecutive years ever since the city codified its urban air quality index and began measuring its urban air quality.

Last year saw the most number of good air quality days (≤15 μg/m3) at 182 days, and exceeded bad air quality levels (>35 μg/m3) at only 31 days. Such outcome is analyzed to be a combination of the international community’s concerted efforts to improve air quality and meteorological conditions as well as the city’s special measure to improve its urban air quality announced and implemented in 2007 as “Clear Seoul 2010.”

The city is also boasting its successful conversion of all diesel city buses to eco-friendly compressed natural gas (CNG) buses and has implemented low-emission measures on about 510,000 vehicles so far as part of its large-scale low-emission project for diesel vehicles.

The SMG Research Institute of Public Health and Environment also analyzed the air quality modeling system and estimated that the actual PM2.5 levels in 2022 were lower by 1.6 μg/m3 compared to the originally expected annual average due to the reduction of domestic and global emissions.

Moreover, the meteorological conditions seem to have had a favorable influence as there were increased amount of precipitation and decreased days of air stagnation in 2022 compared to the last three years. Looking at the impact of PM carried in from abroad, it is estimated that the improvement in air quality in the northeastern part of China also had a positive effect on the improvement of air quality in Seoul.

Seoul will continue to implement policies throughout 2023 to reduce PM levels and improve air quality, targeting various sources such as automobiles, homes, businesses, and construction sites, so that citizens can enjoy a clearer Seoul.