The smog worsened in north China yesterday and the meteorological centre upgraded its alert from yellow to orange, the second most serious level.
All schools in the Chinese capital Beijing have been ordered to keep students indoors and adjust classroom activities as heavy smog blanketed the city of 21 million for the third day as top emitter of greenhouse gases China grappled with heavy pollution.
The Beijing No 2 Experimental Primary School today allowed students to choose whether to study at home or in school while Beijing Digital School is running classes online in view of the high levels of pollution in the city.
The smog worsened in north China yesterday and the meteorological centre upgraded its alert from yellow to orange, the second most serious level, state-run Xinhua news agency reported today.
Highways in Beijing and Henan province have been temporarily closed due to low visibility.
Increased use of coal for heating during winter has been the main factor behind surging levels of PM 2.5, airborne particles that measure less than 2.5 microns in diameter and are especially harmful to human health, said the Beijing Municipal Environmental Monitoring Centre said.
An unfortunate combination of weather conditions has also helped trap pollutants, according to meteorologists -- cold air closer to the ground resulting from thawing snow reduced the mobility of airborne pollutants, officials said.
The smog will continue in most parts of north China on Tuesday and Wednesday, the National Meteorological Center (NMC) forecast.
Yesterday, more than 200 expressways were closed and residents were advised to stay indoors as China grappled with the worst smog of the year.
The public has been warned to take protective measures when engaging in outdoor activities and those who suffer from respiratory diseases are advised to stay indoors.
China is the top polluter along with the US in green house gases. Last year, the two reached an agreement to take ambitious action to limit greenhouse gases.
Smog has shrouded much of northern China including Beijing, Tianjin, Hebei, Henan, Shandong, Shanxi and Shaanxi provinces.