On Monday, the fine particulatematter PM 2.5, a major pollutant touched in many cities in northern China, mainly in Hebei and Henan, exceeded 500 micrograms per cubic meter, crossing the highest levels of hazardous pollution.
State media reported Monday that more than 700 companies stopped production in Beijing, and that traffic police were restricting drivers by monitoring their license plate numbers.
Numerous cities are under red alert for severe air pollution as it is also predicted that situation may worsen due to not so favourable weather conditions.
CHINA Engulfed in choking smog, some northern Chinese cities limited the number of cars on roads and temporarily shut down factories yesterday to cut down pollution during a national "red alert". While the evidence they can afford true defence against air pollution would appear to be scant, Wang says they can help raise awareness of the problem.
The South China Morning Post reported that flight tickets to resorts in the less-polluted south of the country were almost sold out, as Beijing's "smog refugees" prepared to flee the city.
In Shandong, more than 100 toll gates on four expressways were closed and some flights were delayed by more than two hours.
A plane carrying the chief executive of the world's biggest oil exporter was prevented from landing in the Chinese capital of Beijing on Tuesday because of thick smog blanketing large swathes of northern China.
Emergency measures such as auto restrictions based on even-odd licence plate numbers will end and schools will resume classes.
The issue is a source of enduring public anger in China, where fast economic growth in recent decades has come at the cost of widespread environmental degradation.
Previous research work have found equally alarming results about China's toxic air.
Tonny Xie, director of the Clean Air Alliance of China, said: "China's long-term clean air vision requires the cleaning up of both the industrial structure and energy structure".
While the air-quality index used by the U.S. Environmental Protection Agency stops at 500, several Chinese cities had readings that far surpassed that number as of early Tuesday. Beijing's red alert for air pollution was its first of this year, keeping schools closed.
According to weather forecasts a wind from the north should blow most of the pollution away on Thursday.
Flights had already been affected at other airports, including in the neighbouring city of Tianjin.