Korea is inevitably affected by pollution in China, the world's biggest mercury polluter. But until recently, Korea had no idea how serious the problem was. Lee Seung-mook, a professor at Seoul National University’s School of Public Health on Sunday said about half the mercury pollution in the air in Seoul comes from China. The worst offenders are industrial centers like Shanghai, Hangzhou, and Guangzhou. Lee and his team said the mercury pollution is blown in at all times, not just during the annual sandstorms.

A NASA satellite photograph of smog including mercury pollution traveling on winds from China into the sky over the Korean Peninsula on Jan. 27, 2006. At the time, mercury concentration in Seoul’s air was over 10 times higher than normal./Courtesy of visibleearth.nasa.gov

The scientists analyzed about 30,000 air samples collected from Yeongeon-dong, Jongno-gu, Seoul over 13 months starting February 2005. The average concentration of mercury was 3.21 nanogram (1 ng= 1 billionth of a gram) per cubic meter of air, about three times the concentration in natural conditions. The concentration soared to 38 ng, an increase of over 10 times, from late January to early February 2006. The team retraced the travel routes of the winds blowing from China for 72 hours, and tried to locate the sources of mercury pollution based on the discharges of mercury in China and their relations with other pollutants. They concluded, that 48 percent of the mercury pollution in Seoul’s air originates from China.

"We used the same research methods used in the international academic community to discover that the mercury pollution discharged from industrial areas in China travels across the Pacific and all the way to the U.S. coast,” Lee said. The result of the study, conducted with the support from the Korea Science and Engineering Foundation, will be released at a symposium sponsored by the Korea Society for Atmospheric Environment on May 2.

South Koreans are exposed to a much more dangerous level of mercury pollution than advanced countries. The result of a government survey of health and nutritive conditions of the people released early last year showed that mercury concentration in the blood of adults was five to eight times as high as those in the U.S. and Germany. But the government offered no adequate response to this, lacking until recently the equipment to measure mercury concentration in the air. It only recently purchased some equipment from abroad. That explains why the government until recently failed to offer a convincing explanation of the high mercury concentrations in people’s blood.

In the U.S., Chinese mercury accounts for about 20 to 30 percent of the mercury seeping into soil and rivers. The mercury concentration in the blood of Americans is much lower than that of Koreans. Mercury concentration in U.S. air is only 14 to 44 percent of Korea’s, but the U.S. is acting. In 2001, the U.S. measured the amount of mercury originating from China by repeatedly launching aircraft over the seas around the Korean Peninsula. When Chinese President Hu Jintao’s visit to the U.S. was imminent in March last year, Washington warned Beijing to reduce mercury emissions.

The Korean government has belatedly lumbered into action. "We have commissioned a research project to survey the amount of Chinese mercury pollution,” an Environment Ministry official said. “Research will be conducted over three years beginning this month. Please understand that the government has started reacting to Chinese mercury pollution." The ministry is also looking at joint research with the UN Environment Program (UNEP), the U.S., Japan, and China. Chung Suh-yong, a professor of Myongji University, said, "Chinese pollutants crossing borders will become an issue. We need to strengthen international cooperation, including intensifying research, from an environmental security viewpoint to guarantee public health and safety."

(englishnews@chosun.com )