Decisive Evidence Links Korea's Toxic Haze to China

A new study offers decisive proof that much of the toxic smog covering the Korean Peninsula comes from China.

Researchers in Korea have detected substances in fine dust particles collected here that came from Chinese fireworks that were used during the New Year's festival last year.

The Chinese government has been dragging its feet on the Korean government's demands to reduce smog levels by citing a lack of definitive evidence.

But Jung Jin-sang at the Korea Research Institute of Standards and Science said Tuesday, "We have scientifically proven that atmospheric pollutants from China enter Korea to aggravate the concentration of fine-dust levels."

Fine dust refers to ultra-small particles of dust that cannot be seen with the naked eye and are usually formed by burning coal and other types of fossil fuels. They measure only 1/20 the thickness of a human hair and cannot be filtered by the bronchial tubes, resulting in various kinds of lung diseases and infections.

Researchers developed a system of detecting in real time chemical substances that are created when fireworks are detonated, and measured fine dust levels on Jan. 30 last year during the New Year's festival in China.

The density of potassium in the atmosphere surged to eight times higher than ordinary levels, while other substances generated when fossil fuels are burnt remained almost unchanged. The fine-dust levels in nine cities throughout Korea, including Daejeon, reached "bad" levels of 51~100μg/m³ that day.

"No fireworks were detonated in Korea during the same period, leading us to conclude that the fine dust came from China," the researchers said. "It usually takes a day for atmospheric pollutants to travel from China to Korea, and it is estimated that fine dust generated by fireworks in China on Jan. 28 and 29 had reached Korea."

Chinese traditionally believe that the more fireworks are set off, the more they can ward off ill fortune and bring good luck. As a result, massive fireworks displays are staged during the New Year's festival season.

Chinese government attempts to curb the practice have proven largely ineffective. The fine-dust level in Beijing during last year's New Year's festival on Jan. 28 surged from 75㎍/㎥ to 647㎍/㎥, 26 times higher than the level recommended by the World Health Organization (25㎍/㎥).

"This is the first time we have obtained proof that fine dust detected during a particular period of time originated from China," Jung said. "We should be able to use the data in conducting joint research with China to reduce smog in Northeast Asia."

Their latest findings will be published in the April edition of the academic journal, Atmospheric Environment.

More and more studies are showing that China is the main source of the toxic smog. The Korea Institute of Geoscience and Mineral Resources published findings earlier that fine-dust samples collected in Korea in 2016 contained traces of lead found only in China. After analyzing samples, the institute concluded that 87 percent of heavy metal substances found in fine dust in Korea came from China.

Also in 2016, the Ministry of Environment conducted joint research with NASA, which found that China accounts for 34 percent of total fine dust in Korea.

In March last year, the science journal Nature published research showing that 30,900 people were killed in South Korea, Japan, Mongolia and North Korea in 2007 due to smog from China. The same study showed fine dust being responsible for the deaths of 1.19 million people in China, but the Chinese government refused to admit responsibility for the problem.

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