Yellow dust shrouds Seoul, central region for third day

According to the National Institute of Environmental Research's Air Quality Forecasting Center, the density of fine dust particles smaller than 10 micrometers in diameter, known as PM 10, remained at the «bad» level in the greater Seoul area and the central provinces of Chungcheong, Yonhap reports.
The weather authorities here categorize concentrations of PM 10 between zero and 30 micrograms as «good,» between 31 and 80 as «normal,» between 81 and 150 as «bad,» and more than 151 as «very bad.»
The PM 10 figures have returned to normal levels in almost all of the southern region and on Jeju Island, the center said, adding the fine dust density can worsen to the bad level in those areas anytime during the day.
As of 2 p.m., the daily average concentration of PM 10 reached 94 micrograms per cubic meter in the central administrative city of Sejong, 90 micrograms in Daejeon and Gyeonggi Province, 86 micrograms in South Chungcheong Province and 80 micrograms in Seoul, the center noted.
The fine dust concentrations may continue to remain at bad levels in some central and western regions Friday as well, it said.
«Some areas in the central and western regions will remain under the influence of the residue of the externally and locally generated fine dust,» an official from the air quality center said.