Beijing has issued its first air pollution red alert of the year, with the most severe smog since autumn set to start on Friday night and last for five days.
Another 22 northern cities have been advised to follow the capital and issue the highest emergency response, the Ministry of Environmental Protection said on Thursday.
The red alert, effective from 8 pm Friday, will see tougher restrictions introduced for private car owners, who will be allowed to drive only on alternate days depending on their license plate number, the Beijing municipal government said.
The move also brings a suspension of industrial production and, to reduce dust, work at construction sites. Residents are advised to stay indoors.
The smog, expected to be the worst since autumn in severity, length and size of the area affected, is forecast to cover Beijing and Tianjin as well as the provinces of Hebei, Shanxi, Shandong and Henan from Friday until Dec 21, according to Liu Bingjing, head of air quality management for the ministry.
The worsening air quality is forecast to peak and remain at the most severe level over the weekend.
The red alert is the highest level in the four-tier emergency response system against air pollution, followed by orange, yellow and blue.
Another nine cities, including Jinan in Shandong province, are advised to issue orange alerts, Liu said, adding it would be the third time this month city governments had jointly issued emergency measures in December, in this case covering 32 cities.
From Dec 2 to 4, 60 northern cities issued alerts and conducted coordinated control efforts, and during the bout of smog from Dec 9 to 12, 24 cities joined in the regional joint efforts, the ministry said.
"It is suggested the affected regions issue the alerts jointly and before smog comes, which has proved effective in reducing pollution," said Chai Fahe, a senior researcher at the China Research Academy of Environmental Sciences.
During the smog of Dec 2 to 4, the concentration of PM2.5 — tiny particulate matter that can enter the bloodstream — was lowered by 20 micrograms per cubic meter on average in the northern region.
The northern areas have been hit by smog frequently since October, "mainly because of the unfavorable weather for the dispersal of pollutants, large emissions from local pollution sources and pollutants transferred from neighboring areas", said Bai Qiuyong, head of the National Environmental Monitoring Center.
