Buildings in central Beijing are immersed in heavy smog.

Days of less than 500m of visibility were three consecutive days.

Even today (10th) morning, Beijing's air quality index has exceeded 200, a serious pollution level.

[Beijing Citizen: A big boy coughed all night. The bronchus is bad originally, but when the smog gets worse, I cough.] Chinese environmental authorities cited atmospheric congestion as the number one cause of smog this year, which was rated the worst this year.

The impact of the El Niño phenomenon is that the north wind sweeping the smog is weak, so air pollutants build up better and stay longer.

For this reason, Chinese authorities have predicted that "air pollution is high and wide this winter."

New air pollution measures have worsened the situation.

In light of the economic slowdown, policies that have assessed air pollution reduction measures by companies may lead to poor crackdowns. Another reason is the failure to quickly change coal heating, which is the main cause of air pollution, to guarantee people a warm winter.

Indeed, while coal has reduced its share of China's energy production, the absolute use of coal has increased.

Last month, a joint study by Korea, China and Japan found that the impact of smog from China during the winter season reached 70 percent, but China still argues that the impact is only 32 percent over the entire year.

(Video coverage: Choi Duk-hyun, Video editing: Oh No-young)

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