Highly dense fine dust and yellow dust from China has enveloped much of South Korea.

According to the National Institute of Environmental Research on Friday, fine dust, or particulate matter smaller than ten micrometers in diameter, are forecast to remain "bad" at between 81 and 150 micrograms per cubic meter in most parts of the country.

Fine dust levels are expected to rise above 150 micrograms per cubic meter to be "very bad" in the central cities of Daejeon, Sejong, the southwestern North Jeolla Province and city of Gwangju as well as the southernmost island of Jeju.

As of 8 a.m., the average fine dust level in Seoul reached 140 micrograms per cubic meter, while density shot up to 199 micrograms per cubic meter in the southwestern Jeolla city of Gunsan and 209 micrograms per cubic meter in the eastern Gangwon city of Sokcho.

Fine dust advisories are in place for the capital area, the central Chungcheong provinces, the southwestern Jeolla Provinces, the southeastern North Gyeongsang Province and the southernmost Jeju Island.