China's top environmental watchdog on Friday criticized a South Korean media report that claimed air pollutants from China are to blame for recent air pollution in South Korea.

Liu Youbin, spokesman of the Ministry of Ecology and Environment, said the consistent decrease of PM 2.5 – pollution that carries health risks –, in China and the concentration of the pollutant in South Korean capital, Seoul, in recent years is one of the factors that will not support such media report.

He also told a press conference in Beijing that comparing the density of nitrogen dioxide in the two countries further refutes the report.

The nitrogen dioxide concentration in Seoul from 2015 to 2017 was higher than that in Beijing and Chinese cities close to South Korea, such as Dalian in Liaoning province and Yantai in Shandong province, he said.

Nitrogen dioxide is considered a precursor of particulate matter like PM 2.5.

Both Chinese and South Korean research on the smog that occurred in Seoul from Nov 6 to 7 shows that the pollution was caused by local emissions, he said.

Research conducted by Chinese experts shows,no evidence of meteorological conditions conducive for the large-scale transportation of air pollutants from China to South Korea in early November.

According to media reports, South Korean experts reached similar conclusions, he said.

China, South Korea and Japan are now conducting joint research on the long-distance transportation of air pollutants in northeast Asia and results will be made public in late 2019, he said.