Fine dust chokes nation just before cold snap begins

Social Affairs

Published: 23 Nov. 2023, 18:59 Updated: 23 Nov. 2023, 19:00

Fine dust chokes nation just before cold snap begins

Downtown Seoul on Thursday is blanketed by fine dust from overseas. Korea's central and southern regions were engulfed with heavy fine dust on Thursday, with the authorities issuing fine dust and ultrafine dust advisories for the first time in the fall season. [KIM JONG-HO]

Korea’s air quality Thursday was the worst this season, with fine dust and ultrafine dust advisories issued in central and southern regions of the country.

Fine dust is expected to clear away as cold air arrives. A cold snap is expected to send temperatures plummeting with cold wave advisories in effect as of Thursday night.

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Ultrafine dust advisories were issued in many parts of the greater Seoul area and South Chungcheong on Thursday morning.

This marked the first time in six months that parts of the country were issued such advisories.

The Seoul Metropolitan Government’s Research Institute of Public Health & Environment issued ultrafine dust advisories in the capital at 9 a.m. and fine dust advisories at 11 a.m.

According to the institute, large amounts of fine dust began arriving from overseas at dawn Thursday.

Ultrafine dust refers to PM 2.5, or particles smaller than 2.5 micrometers in diameter, while fine dust refers to PM 10, or particles smaller than 10 micrometers in diameter.

Fine dust advisories are alerted when the average concentration of fine dust remains above 150 micrograms per cubic meter for over two hours, while ultrafine dust advisories are issued when its average concentration lingers higher than 75 micrograms per cubic meter for more than two hours.

People are advised to refrain from staying outdoors for a long time and to wear masks when they head out when these advisories are issued.

Kindergartens and elementary schools are also recommended not to hold outdoor classes.

The ultrafine dust level in the greater Seoul area remained within the “bad” level — the third level of the four-tier system — as of 5 p.m. Thursday, while the South Gyeongsang and Jeolla regions also saw bad levels of such pollutants, according to the Ministry of Environment’s real-time air data from Air Korea.

The ultrafine dust concentration in Seocho District, southern Seoul, reached as high as 122 micrograms per cubic meter in the morning, falling in the “very bad” level.

The hourly average of ultrafine dust concentration nationwide reached 47 micrograms per cubic meter, falling in the bad level range of 36 to 75 micrograms.

The fine dust blanket is expected to clear away from Thursday night, beginning in the greater Seoul area, as the atmospheric environment improves.

Temperatures in the country will drop starting Thursday night. Cold wave advisories were in effect in many regions, including Seoul, parts of Gyeonggi, Incheon, Gangwon and Busan, as of 9 p.m. Thursday.

Morning lows will drop to as low as minus 7 degrees Celsius (19.4 degrees Fahrenheit) in Daegwallyeong, Gangwon, and to minus 4 degrees in the capital. Parts of the Chungcheong and Jeolla regions will see 1 to 3 centimeters (0.3 to 1.2 inches) of snow.

On Saturday, average morning lows will dip to minus 10 degrees Celsius. Midday highs will hover around minus 4 degrees Celsius in the greater Seoul area.

BY CHO JUNG-WOO [cho.jungwoo1@joongang.co.kr]