April 20 (Bloomberg) -- Beijing's heat and humidity in August, not pollution, may be bigger concerns for some of the athletes who'll be running the marathon at the Olympic Games.

``It'll be really hot, really humid. I think it'll be really tough,'' Mara Yamauchi, winner of this year's Osaka Marathon and part of the British Olympics team, told reporters in Beijing today. ``I'm not going to acclimatize to pollution, I don't think you can do that. Heat you can acclimatize to.''

Athletes and national teams have raised concerns about Beijing's pollution, and the International Olympic Committee has said it may reschedule endurance events affected by smog. World record holder Haile Gebrselassie, who has asthma, has said he is pulling out of the marathon in Beijing because the pollution and heat may harm his health.

Beijing has spent 120 billion yuan ($17 billion) on more than 200 projects to improve air quality, with the number of ``blue sky days'' in the city more than doubled to 246 last year from 100 in 1998.

``I don't think they can sort out the pollution and just magic it away,'' said Yamauchi, seventh in a women's marathon competition today, which was part of a series of test events Beijing is hosting in the lead-up to the Olympics. ``They can do things to reduce it and they're going to do it.''

Serod Batochir of Mongolia, who won today's men's marathon race in a personal best time of 2 hours, 14 minutes and 15 seconds, said the weather is a bigger challenge to performance.

``The heat and humidity may be a more serious concern than pollution,'' Batochir, who qualified for the Beijing Olympics, told reporters today.

Dry Throat, Itchy Eyes

Still, Yamauchi, who experienced dryness in her throat and itchy eyes, may use a mask when training in the Chinese capital city in the days leading up to the marathon in August. ``I'll consider it, anything that can help me perform my best on the day is worth trying,'' she said.

Zhou Chunxiu, winner of the 2007 London Marathon and a member of the Chinese Olympics team, will be training in Beijing before the Games to acclimatize herself to the heat and humidity. Zhou finished second in today's race at 2:37:49.

``Beijing is hot and humid in August and my top concern is to train myself to get used to running under such conditions,'' said Zhu Xiaolin, also part of the Chinese Olympics team and third in among women in today's race, also at 2:37:49. ``How well I will perform in August is also dependent on the weather.''

Heat, Humidity

Chen Rong of China, who has yet to qualify for the Olympics, won the women's race today with a time of 2:30:42.

Maximum temperatures in the Chinese capital city average more than 29 degrees Celsius (89 Fahrenheit) in August and rainfall varies from 32.5 millimeters (1.3 inches) to 71.2 millimeters.

Italy's Stefano Baldini, Olympic marathon gold medalist in the 2004 Athens Games, said last week that heat and humidity may be the bigger challenge for endurance runners in August.

Runners in today's marathon test event said the route for the race through Beijing was flat and that athletes may achieve good results in August.

To contact the reporter on this story: Wing-Gar Cheng in Beijing at wgcheng@bloomberg.net.

Last Updated: April 20, 2008 04:19 EDT