Reuters

BEIJING - International Olympic Committee scientists have proved that Beijing's air will present no health risk to athletes competing for up to an hour at the 2008 Games, IOC chief inspector Hein Verbruggen said on Wednesday.

Beijing is one of the most polluted cities in the world and despite a 120 billion yuan ($17.12 billion) clean-up over the last decade, pollution remains a concern for many athletes coming to the Olympics, already a lightning rod for rights protests worldwide.

Verbruggen, chairman of the IOC coordination commission, said there was a small risk for athletes in longer events on the worst-polluted days but the IOC had plans to reschedule events should the worst occur.

"The Chinese together with our medical commission have done an excellent job," the Dutchman told Reuters on the sidelines of the final inspection of preparations for the August 8-24 Games.

"They have scientifically proved there is no risk for the wide majority of sports. There can be a risk, but it's not big, for endurance events that last longer than an hour.

"In that case, we are developing a Plan B. We might delay certain events for a couple of days. But to do that it must be very bad."

IOC press commission chief Kevan Gosper said Beijing's investment had delivered better air quality and he was confident that contingency plans would deliver.

"At Games time, they've got many levers to pull ... they've given us a great list of details of what they propose to do," he said.

"Every Games I've been to as an administrator since 1984, we've worried about air quality ... in all cases, things turned out to be normal," he added.

Beijing plans to take about half of its 3.5 million cars off the roads and partially shut down industry in the capital and five surrounding provinces for two months for the Olympics and following Paralympics.

City authorities have trumpeted the rise in the number of "blue sky days" -- from 100 in 1998 to 246 last year -- as evidence of the improvements already made.

Some athletes have not been reassured. Marathon record holder Haile Gebrselassie, an asthma sufferer, said last month he would not compete in the event in August because of the pollution.

The "blue sky day" scale has not been widely recognized by international scientists and some foreign media have accused local officials of fiddling with measures to get the desired results.

"There'll always be critics, but it's out there for people to see and for those of us who've been coming here for thirty years, there's tangible evidence of dramatic improvement," said Gosper.

"I believe they've done a great deal on air quality and I don't believe it will be an issue at Games time."