The concentration of ultrafine dust (PM2.5) in western regions such as Seoul, Jeonbuk, Chungnam, Gyeonggi and Incheon has been “bad” for the second day, and the ultrafine dust advisory continues on the 16th. Nine months have passed since the 22nd. February, an ultrafine dust advisory was issued in Seoul.
On the 15th, when the concentration of fine dust in the metropolitan area like Seoul was “bad”, the city sky covers the city sky from Ansan-gil, Seodaemun-gu, Seoul. / yunhap news
According to the National Academy of Environmental Sciences of the Ministry of Environment, the concentration of ultrafine dust in the metropolitan area, Gangwon area, Chungcheong area, Jeonbuk, Daegu and Gyeongbuk was forecast to be “bad” on this day. Other areas would be “normal”, but Gwangju, Ulsan and Gyeongnam are forecast to be temporarily “bad” in the afternoon.
The average daily concentration of ultrafine dust at 12 o’clock that day was 58㎍ / ㎥ in Sejong, 55㎍ / ㎥ in Chungbuk, 50㎍ / ㎥ in Gyeonggi-Gangwon and 44㎍ / ㎥ in Seoul. When the ultrafine dust concentration exceeds 35㎍ / ㎥, it is ‘bad’ and when it exceeds 75㎍ /, it is ‘very bad’.
The National Academy of Environmental Sciences predicted that “in most regions, the concentration of fine household dust will accumulate due to atmospheric congestion and air stream convergence, and the concentration will be high, and in the eastern region, the concentration will be high as foreign fine dust is added starting in the afternoon.
The 17th is also expected to be “bad” in southern Gyeonggi and Daegu, and “bad” in Seoul, Incheon, northern Gyeonggi, Chungcheong, and Jeonbuk in the morning. Other areas were forecast as ‘good’ to ‘normal’.
The reason ultrafine dust has such a “bad” concentration is that fine dust introduced from abroad, such as China and North Korea, has accumulated due to the stagnation of the domestic atmosphere. As heating began in China and factory operations increased, China’s smog, which had been quiet for a while due to the corona crisis, began to rise again, an analysis suggests that fine dust introduced from China increased.
Air quality prediction model for ultrafine dust on the Korean peninsula at 8 pm on the 16th / Capture from the website of the National Institute of Environmental Sciences
According to the Center of China National Air Pollution Prevention Association, air pollution advisories went into effect in 54 northern Chinese cities centered on the China metropolitan area, including Beijing, Tianjin and most of the Hebei cities. In 47 of 54 cities, the second of the three levels of Chinese smog warnings (red, orange and yellow) was issued, the orange warning, and seven cities had the third stage of the yellow warning. An orange alarm is issued when an Air Quality Index (AQI) of 200 or higher continues for more than three days or an AQI is higher than 300, and a yellow alarm is triggered when an AQI of 200 or higher continues for two or more days. more days.
The Chinese environmental authorities said that the cause of the air pollution was “because the central heating supply in northern China started in winter and the volume of traffic increased”, and “it is also the reason why industrial production is resumed due to recovery from corona situation. ”
