Beijing (AsiaNews/Agencies) - Air pollution continues to be an emergency across China.
Whilst pollution levels have exceeded 300 every day in the capital (anything above 300 is considered 'severe'), the authorities were forced to close schools in the provincial capital of Jiangsu for 'at least' three days.
Until this evening, pollution is also expected to remain above 'dangerous' levels in Beijing, Tianjin, and in the provinces of Anhui, Hebei, Jiangsu and Zhejiang.
The main cause is smog (measured in PM 2.5 or particulate matter under 2.5 micrometres in size) due to industrial emissions, combined by winter weather.
With the arrival of the cold, millions of heaters were turned on, increasing coal use in power plants.
In Shanghai, PM2.5 levels exceeded 600 mcg per cubic metre, whilst in Beijing they reached 473 mcg. For the World Health Organisation, the safe limit for PM2.5 is 25 mcg per cubic metre.
Air travel was also disrupted. Some 170 domestic flights into and out of Beijing were affected by the smog yesterday and 93 were cancelled.
A total of 111 domestic flights were cancelled in Nanjing yesterday, leaving 8,000 passengers stranded.
Even in Shanghai, which has two international airports, 144 flights were cancelled, but the air quality "improved slightly".
"Every region has to clean its own mess instead of waiting for others to go first," said Chai Fahe, vice-director of the Chinese Research Academy of Environmental Sciences. Otherwise efforts will be useless.
However, "Steps taken by the Shanghai government to alleviate pollution aren't enough," said Huang Wei, who works on climate and energy issues for Greenpeace in Beijing.
"Smog brings a huge health risk to the public," he added. It "definitely affects multinational companies' investment decisions and makes them hesitate before sending foreign employees to China".