A man wearing a mask walks in Gwanghwamun, central Seoul, Tuesday, as fine dust hit the country. Ultrafine dust warnings have been issued for western Incheon and parts of the nation's central area. / Yonhap



By Jhoo Dong-chan

The Korean Peninsula has been blanketed by a layer of fine dust, with ultrafine particle advisories issued for the western Incheon area and other parts.



According to the National Institute of Environmental Research (NIER), Tuesday, the ultrafine dust advisories were issued in western Incheon, Wonju and Chuncheon in Gangwon Province.



Samplings from those regions showed the presence of ultrafine dust, or particulate matter (PM) 2.5, meaning dust the size of 2.5 micrometers or less in diameter, nearly one-30th the thickness of a human hair.



Some other regions of the country, including central and southern Gyeonggi and Cheongju in North Chungcheong Province, issued advisories for fine dust, or PM10, meaning 10 micrometers or less.



Most of the country has issued advisories for two consecutive days since Monday.



The dust levels all over the country were up fourfold the seasonal average.

It is highly likely for the advisories to expand to southern regions of the peninsula, according to the NIER.



"The advisories will last at least two to three more days," said a NIER official. "Central parts of the country will continue to be under the fine dust advisory if there is no rain."



She said the fine dust has come some 10 to 20 days earlier than usual, as Korea usually has such weather conditions in late October or early November. "Fine dust from China usually passes through the peninsula to the East Sea, but these days we have easterly winds that have trapped the dust in the central region," the official said.



A months-long drought is aggravating the situation, as rainfall usually washes away the dust, she added.



PM10 is accumulated directly in the lungs and excessive exposure to it can cause severe problems including difficulties in breathing or seizures, experts say. Especially PM2.5 can pass through the pulmonary alveoli, directly causing various respiratory diseases and weakening the immune system.



Especially, once ultrafine dust is inside the human body, there is no way to remove them from the body.



Experts say that once fine dust advisories are issued, vulnerable people such as children, the elderly and patients with respiratory problems are advised to stay inside and restrict outdoor activities. Everybody is advised to avoid outdoor activities while the dust is as heavy as it is.



"Advisories for two consecutive days can indicate serious effects on public health," the NIER official. "Residents should take special precautions."



Experts say that it is necessary to wear special masks designed to prevent being affected by the fine dust.