'75% of Korea's fine dust came from China'

A man looks down on Seoul's fine dust-covered cityscape from Mount Nam in central Seoul, Wednesday. The ultrafine dust level was “bad” all day long in Seoul and other metropolitan areas. / Yonhap

By Jung Hae-myoung

About 75 percent of the ultrafine dust that covered the Korean Peninsula for days last month came from China and other nearby countries, according to a study by the National Institute of Environmental Research (NIER), Wednesday.

The study contradicts previous claims by the Chinese government that most of the fine dust in Korea was from domestic causes.

The institute under the Ministry of Environment analyzed meteorological observation records of ultrafine dust from Jan. 11 to 15 when Korea saw its highest levels. According to the study, the “influence from outside Korea” took up between 69 percent and 82 percent of the origin of ultrafine dust during the period, or 75 percent on average.

The “outside of Korea” means adjacent countries including China, Mongolia, North Korea and Japan. The NIER did not specify one country, but it seems China was the main cause considering the direction of winds and the amount of air pollution the countries generate.

The high concentration of ultrafine dust started Jan. 10 and 11 with high pressure from Shandong Province and northern China “seeding” winds that blew onto the peninsula. Another northwester pushed dust toward Korea for the second time from Jan. 13, the institute said.

During the period, the levels of nitrates, sulphates and aerosols were much higher than usual, up to 11.9 times in the case of sulphates.

“Both Korea and China had high pollutant levels with a long-term accumulation of dust,” an institute official said. “We'll deliver the study results to China and strengthen cooperation in research.”

At a government policy meeting among Korea, China and Japan to be held in Japan, Feb. 20, the ministry plans to hold a separate session to discuss the study and discuss sharing fine dust forecast data.