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Concentration was unusually low in the first half of this year.
Expert “The increasing trend of air pollutants in China … As if the influx of the Korean peninsula increased with the west wind.”
Ultrafine dust (PM2.5) that has been quiet for a while is making a comeback. On the 20th, the average daily ultrafine dust concentration in Seoul, southern Gyeonggi and Chungcheong is expected to rise to “bad”. Bad corresponds to 36-75 µg per m³ (microgram, 1 µg is 1 millionth of a g). It has been 110 days since July 2 that the average daily concentration of ultrafine dust has turned bad in Seoul. In particular, there are worrying prospects that the ultrafine dust situation will be dire this winter.
The National Academy of Environmental Sciences predicted that high pressure near China’s Shandong Peninsula on the 19th approached the Korean Peninsula and introduced air pollutants, and the average daily concentration of ultrafine dust in the Midwest on the day 20 was at a bad level. As the air in the metropolitan area became cloudy since the afternoon of the 19, the hourly concentration increased. At 9 p.m. on the day, the hourly ultrafine dust concentration shot up to 93 μg in Siheung, Gyeonggi-do and 70 μg in Seocho-gu, Seoul. The phenomenon of high concentration of ultrafine dust is expected to be resolved in the afternoon of the 20th when the east wind blows.
According to the Central Meteorological Office of China, on the 19th, mild (level 3) to moderate (level 4) air pollution occurred in Beijing, Tianjin and Hebei, located on the Shandong Peninsula. did. China’s ‘Air Quality Index (AQI)’ is divided from the best level 1 to the most serious level 6. Moderately, the elderly with respiratory problems should refrain from outdoor activities. This year, the concentration of ultrafine dust was low in Korea. From January to September, the average daily concentration of ultrafine dust is 18 μg per m³. Compared to the average (24 μg) for the same period from 2017 to 2019, it is 25% lower. The causes are complex. The government believes that the impact of the seasonal management system introduced in December last year, as well as the decrease in traffic and economic activity due to the new coronavirus infection (Corona 19), increased rainfall and wind in comparison with normal years, and the seasonal management system introduced in December last year. Both Corona 19 and the weather conditions are unusual.
Consequently, experts predict that the ultrafine dust concentration will increase again if there is not much rain or wind this winter. Professor Kim Joon from the Department of Atmospheric Sciences at Yonsei University explained: “Air pollutants in China have decreased until this spring due to the influence of Corona 19, but now they have increased again.” Air pollution can be somewhat reduced if the seasonal management system, which is implemented from December to March of the following year, is carried out correctly. The seasonal management system includes policies to reduce the operation of coal-fired power plants and the emission of atmospheric pollutants from large companies. In May this year, the National Institute of Environmental Sciences reduced emissions of household pollutants by nearly 20% through seasonal management, and the result of the analysis showed that even if pollutants from China arrived similarly, the concentration ultrafine powder, which had shot up to ‘very bad’, was reduced to ‘bad’ Has been released. The phenomenon of high concentration of ultrafine dust occurs when atmospheric congestion occurs when pollutants emitted by domestic pollutants and imported from abroad are found.
Meanwhile, there is also the expectation that this winter, the cold air of the Arctic could become a ‘saving pot’ that will decrease the concentration of ultrafine dust. Hanyang University Professor of Ocean Convergence Engineering explained: “If you take a look at the weather conditions so far, there is a chance that this winter, the cold and clean air from the Arctic will hit the Korean Peninsula more often. than in previous years, accompanied by strong winds to expel ultrafine dust.
Reporter Kang Eun-ji [email protected] Go to reporter’s page>
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