"The clearest Seoul sky last year" Lowest fine dust concentration since monitoring began

Seoul's Annual Average PM2.5 Concentration Hits Record Low at 19.8㎍/㎥
Record High of 172 'Good' PM2.5 Days, 'Bad' Days Nearly Halved Compared to 2008

[Asia Economy Reporter Lim Cheol-young] Last year, the annual average concentration of fine particulate matter (PM-2.5) in Seoul was recorded at 19.8㎍/㎥, marking the lowest level since air quality monitoring began.

According to Seoul City on the 2nd, the annual average concentration of fine particulate matter in Seoul last year decreased by 23% compared to 26㎍/㎥ in 2008, when monitoring started, and was 1㎍/㎥ lower than the 21㎍/㎥ recorded in 2020. Monthly data shows that although emergency reduction measures were issued three times in March during the first half of the year and dust storms caused poor air quality at times, the concentration steadily declined in the second half, with September recording 7㎍/㎥, the lowest monthly fine particulate matter concentration ever observed.

The number of days with "Good" fine particulate matter levels (~15㎍/㎥) was the highest ever recorded since monitoring began, totaling 172 days. Conversely, the number of days exceeding the "Bad" level was the lowest ever at 35 days. Compared to 2008, the number of "Good" days doubled from 86 days, while days classified as "Bad" or worse were reduced by about half.

Seoul City analyzed that the improvement in fine particulate matter concentrations was due to a combination of domestic and international emission reduction efforts, meteorological conditions, and reduced socio-economic activities caused by COVID-19. In particular, it was assessed that various air quality improvement policies proactively implemented by Seoul City since 2003 have been effective.

The Seoul Institute of Health and Environment also analyzed that the actual concentration last year was 1.3㎍/㎥ lower than initially expected, attributing this to reductions in domestic and international emissions. Modeling analysis assuming last year's emissions were the same as in 2020 showed that the lower annual average concentration compared to the modeled prediction and 2020 levels indicates visible results from efforts to improve air pollution both domestically and abroad.

Additionally, meteorological conditions in the second half of the year, including increased inflow of easterly winds and improved air quality in northeastern China, were also estimated as factors contributing to the lower fine particulate matter concentrations. In 2021, easterly winds accounted for 34.4%, up from the past 10-year average of 25.7%. Notably, northeasterly winds doubled. The annual average fine particulate matter concentration in northeastern China, which affects Seoul's air quality, also decreased compared to the past three years.

Seoul City plans to continue seasonal measures and existing air quality improvement policies by sector, including automobiles, heating, and power generation, so that citizens can experience clearer skies this year as well. Currently, the "Fine Dust Seasonal Management System" is being implemented, strengthening sector-specific reduction measures for four months from December last year to March this year, when air quality typically worsens.

Since its implementation in December, the average daily number of violations of the "Emission Grade 5 Vehicle Operation Restriction" (from the 1st to the 24th) decreased by 78% compared to the previous seasonal management period, with an average of 315 vehicles per day. The installation rate of diesel particulate filters on Grade 5 vehicles increased by 24%. Furthermore, following concentrated inspections of emission sources, four unauthorized or non-compliant facilities were reported. The 224.5 km of intensive management roads across 56 city sections have been cleaned four times more frequently than usual, with cleaning conducted four times daily. This year, a real-time emission source management system based on IoT will be operated continuously, focusing on large emission sources to ensure no gaps in monitoring.

Yoo Yeon-sik, Head of Seoul City's Climate and Environment Headquarters, stated, "The record low fine particulate matter concentration in Seoul last year was due not only to domestic and international meteorological conditions but also to various policy efforts implemented to reduce fine dust." He added, "We will do our best this year as well to ensure citizens can experience clearer skies over Seoul."

This content was produced with the assistance of AI translation services.