Aug. 5 (Bloomberg) -- Beijing's pollution, which strayed above the World Health Organization's recommended maximum for the second straight day, is aiding one Olympic athlete's preparations while choking the plans of others.

Three days before the opening ceremony, Beijing's air pollution index at the main Olympic stadium in the 24 hours to noon today reached 87, exceeding the WHO recommendation of 50.

For Australian marksman Russell Mark, who is preparing for his fifth Olympics, the haze over the shooting ranges might aid his bid for a second gold medal in the men's double trap.

``The smog helps us,'' Mark, who won the event in Atlanta 12 years ago, told reporters in Beijing today. ``I can see the orange disks better in the sky.''

Beijing has spent $17 billion improving air quality for the Aug. 8-24 Games and since last month barred more than half the cars from its roads and closed factories and construction sites.

The International Olympic Committee, which has threatened to postpone events if pollution puts athletes at risk, today said it was confident air quality won't be an issue for athletes and visitors. The committee is using WHO standards to evaluate the city's air, its medical chief said today at the opening of the IOC Session in Beijing.

``Those standards are fairly tough to meet, but in many respects the Beijing area does so,'' said Arne Ljungqvist, chairman of the IOC medical commission. ``I'm confident the air quality will not prove to pose major problems to the athletes and to the visitors in Beijing.''

Heat and Humidity

New Zealand rowers said the city's heat and humidity was a bigger concern, describing it as ``the hottest weather'' they've experienced. Temperatures today reached 35 Celsius (95 Fahrenheit) and humidity dropped to 30 percent from 75 percent as haze cleared in the afternoon.

``The first few days I was stung by the heat,'' single sculler Emma Twigg said. ``The smog has not been an issue.''

Marathon runners had a different perspective.

``We've been talking to the marathon athletes and they were really suffering from pollution, really, really badly,'' Fernando Rivas, coach of the Spanish badminton team, said in an interview. ``They were feeling their throats getting very dry and they can smell the pollution.''

While the smog won't harm Rivas's athletes because they compete indoors, some of their national teammates are expecting challenging conditions.

``When we got off the plane, we immediately noticed the pollution,'' said Spanish cyclist Alejandro Valverde. ``Because of the conditions of the heat, humidity and pollution, it is going to be very demanding.''

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

Last Updated: August 5, 2008 07:12 EDT