Beijing issued its first red alert for air pollution on Monday under a four-tier emergency response system created in October 2013. The red alert, the most serious level, will last from 7 a.m. on Tuesday to noon on Thursday.
Smartphone air quality apps, popular among Beijingers, showed an Air Quality Index (AQI) reading of more than 200 for almost all monitoring stations across the city on Monday, advising people to reduce outdoor activities.
It comes after the worst period of air pollution this year took AQI readings in the capital to the maximum 500 on Nov. 30.
While the city did not issue a red alert during that spell of smog, the rules drawn up two years ago state that a red alert should be issued in periods when the AQI is expected to surpass 200 for three consecutive days.
Under a red alert, the city's emergency management headquarters has advised kindergartens, primary and high schools to suspend classes, banned outdoor operations on construction sites and required some industrial plants to limit or stop production.
Car use will be limited during the red alert period as cars are allowed on the roads on alternating days depending on the odd or even numbers of their license plates. In addition, 30 percent of government cars will be banned from streets on an odd/even basis.
According to the Beijing Municipal Environmental Monitoring Center, heavy smog will linger until Thursday. It is expected to disperse on Thursday afternoon as a cold front arrives.