Olympics Polution

Pollutant levels in Beijing click on the top of the scale on Tuesday, just 73 days before the Olympic games, a government warning for residents with respiratory problems to stay indoors.

"Sensible people should avoid, be outdoors," the Beijing Environmental Protection Bureau said on its website, announcing that the air quality was in "dangerous" level five, the worst note.

The major pollutants has been suspended particles, which is usually attributed to the burning of coal and vehicle exhausts.

But the bureau said this time experts blamed poor air quality in the annual spring sandstorms in Mongolia and China's Inner Mongolia region that had blown thousands of tons of dust on the Chinese capital.

"This is the fourth storm of the season and air pollution were each about the same time, but this time the effect lasted longer," said an official in the office asked not to call.

The pollution was strongest in the early morning hours, but had begun to disperse after lunch, he said.

Beijing is the air quality is routinely rated among the worst in the world of international organisations such as the United Nations and the World Bank, with the increasing number of cars, industrial pollution and dust storms among the culprits.

China says it spent 16 billion U.S. dollars in the last ten years to improve the environment and air quality by moving polluting factories out of the capital, the increase in car emissions standards and other measures.

The authorities have said the city last year achieved its goal of 245 "blue sky days", or days with only light pollution, compared with only 100 days in 1998.

However, Beijing's poor environment remains a major concern for the International Olympic Committee and some athletes.

IOC chief Jacques Rogge said last year that endurance events like the marathon could be postponed or cancelled to protect the competitors' health during the August 8-24 games.

Hoping to avoid embarrassment, Beijing plans for a ban on about half of the city of three million-plus cars from the roads during the Games, while some factories are closed and construction work in order to stop.

Cities and provinces are also in the anti-combat pollution caused by similar measures.