Ten China cities on red alert

More than 100 million people in China have been warned to stay indoors after at least 10 Chinese cities issued red alerts for smog, state media reported yesterday.

Pollution covered large parts of the country's east and centre as measures to curb the toxic haze were ordered to be implemented. Factories are ordered to close and half of all private cars are told pulled off the streets to battle the pollution.

In addition, the eastern province of Shandong, home to almost 96 million and some of the 10 cities under red alert, issued its first ever top-level warning Wednesday, the provincial environmental bureau said.

It is believed to be the first time an entire province has issued a red alert. The ten cities include the sprawling industrial hub of Tianjin in the northeast.

Counts of PM2.5 -- harmful microscopic particles that penetrate deep into the lungs -- in one of the cities under red alert, central Henan Province's Xinxiang, were as high as 727 micrograms per cubic metre earlier yesterday, according to provincial authorities. The reading is nearly 30 times the World Health Organisation's recommended maximum exposure of 25 over a 24-hour period.

Beijing cancelled its red alert for pollution at midnight on Tuesday as a cold front blew away the foul air, state-run Xinhua news service said yesterday.