The persistently high concentration levels of ultra-fine dust are due to atmospheric stagnation. - Photo: AFP
SEOUL: Most of South Korea was covered by thick, ultra-fine dust for the second consecutive day on Wednesday (Jan 22), with such conditions forecast to continue until Thursday (Jan 23), according to the National Institute of Environmental Research (NIER).
According to the NIER, the density of ultra-fine dust particles is forecast to remain at “bad” levels nationwide until Jan 23, excluding some eastern coastal regions in Gangwon province and southern parts of Jeju Island.
The persistently high concentration levels of ultra-fine dust are due to atmospheric stagnation, allowing fine dust generated domestically and flowing in from abroad to continue to accumulate in the air, according to the research institute.
As at 8am on Jan 22, ultra-fine dust warnings were issued nationwide excluding the southern parts of South Gyeongsang province and South Jeolla province.
Warnings are issued for dust particles smaller than 2.5mm in diameter – also known as PM2.5.
South Korea classifies PM2.5 above 35mg per cubic metre as “bad” fine dust levels, while the World Health Organisation recommends keeping levels below 25mg.
Nine local governments, including those in the Greater Seoul area of Seoul, Incheon, and Gyeonggi province, as well as the Chungcheong provinces and North Jeolla province, launched emergency emission reduction measures as at 6am on Jan 22.
In such regions, an order was made by the Ministry of Environment to reduce operations of coal power plants and factories, as well as a road ban for old diesel cars and an alternate no-driving system for public vehicles.
Such emergency reduction measures are expected to last until 9pm on the same day but could continue into Jan 23, depending on the ultra-fine dust forecast.
According to the Korea Meteorological Administration, air quality levels are forecast to be bad across South Korea until Jan 23.
As South Korea falls under a high-pressure system currently lingering over the northern parts of China, northerly winds are expected to blow into the country, pushing the fine dust away.
From Jan 24, most parts of the country can expect to see low levels of fine dust with the exclusion of Gwangju, South Chungcheong province and North Jeolla province, which may continue to see bad ultra-fine dust levels until Jan 24.
As atmospheric diffusion effectively occurs over the weekend, low ultra-fine dust concentration levels will begin to be observed nationwide from Jan 25, according to the NIER. - The Korea Herald/ANN
