Athletics:Marathon world record holder Haile Gebrselassie said on Monday he would not compete in the Olympic marathon because of fears that Beijing's air pollution would damage his health.
The Ethiopian runner, who suffers from asthma, said he would still compete in the shorter 10,000 metres event in the August Games.
"The pollution in China is a threat to my health and it would be difficult for me to run 42 km in my current condition," said Gebrselassie.
"But I am not pulling out of the Olympic event in Beijing all together. I plan to participate in the 10,000 m event," he added.
Pollution is a major issue facing Beijing in the run-up to the Games.
International Olympic Committee chief Jacques Rogge said last year that events such as the marathon could be rescheduled if contingency measures did not have the desired effect.
Gebrselassie called on China to deal with the problem, saying that pollution "would be a hazard to athletes, seriously affecting their performances."
Dube Jillo, technical director of the Ethiopian Athletic Federation, said as far as his federation was concerned, Haile was expected to compete in the Olympics.
"But whether he runs in the marathon event or 10,000 m for which he holds a world record, would be his own choice," said Dube.
Rogge told reporters last November in New York that a monitoring system would be set up in Beijing to gauge whether air pollution warranted delaying events.
Events that involve endurance, such as the marathon or cycling distance races, could be delayed for a few hours or until another day, Rogge said.
"During a marathon for more than two hours, riding a bicycle race for five to six hours -- that could be a danger hazard and then we would postpone the race," he said at the time.