A sandstorm laced with minute pollutants blew in from China and Mongolia on the first day of 2014 to envelop the Korean Peninsula. Sandstorms usually occur in spring and are rarely seen in winter.
The Korea Meteorological Administration on Wednesday said the sandstorm developed in Mongolia and northeastern China on Monday and Tuesday and blew over to the western coast of Korea early Wednesday morning carried by northwesterly winds.
The fine dust density in Seoul and Baeknyeong Island soared to 106~159 ㎍/㎥, higher than the safe level of 100 ㎍/㎥.
The Environment Ministry warned another sandstorm would pass through Korea on Thursday morning, but a northwesterly wind later in the morning would reduce the fine dust density to hover between 31~80 ㎍/㎥.
Weather officials gauge the fine dust density to determine whether the winds are carrying pollutants from burnt coal or automobile exhaust or just sand from China and Mongolia.
Generally, sand particles are larger than minute pollutants, so a higher fine dust density points to pollution.