Up to 60 percent of ultrafine particles in toxic smog that blanketed Korea over the weekend was blown in from Chinas, the National Institute of Environmental Research said Wednesday. It said the density of heavy metals in China's air apparently increased due to serious pollution even as Korea tried to clean up its act.
A study released in 2009 by the institute and Prof. Yoon Soon-chang of Seoul National University found that up to 60 percent of ultrafine particles here originated from China, with 60 percent ions and 55 percent organic and inorganic carbon. The study was based on a computer simulation.
"The situation has changed little over the past years, but since Korea now produces fewer pollutants, an increasing proportion may have come from China," the institute said. The claims are supported by other studies that found a higher concentration of heavy metals in the atmosphere here when sandstorms arising in China are blown in every spring.
A senior NIER researcher said sandstorms collect heavy metals when they pass industrial areas in eastern China before they reach Korea. When the sandstorms hit, the concentration of lead in the atmosphere here rises by 30 percent, of cadmium by 50 percent and of arsenic by 40 percent, he added.