MELBOURNE, Australia — Because of scheduling issues and a concern about air quality, many of Australia's track and field athletes will miss the Aug. 8 Olympic opening ceremonies in Beijing.

With the Beijing athletics program not starting until Aug. 15, one week after the opening, Athletics Australia has chosen to hold its pre-Olympic training camp in Hong Kong.

Competitors will then fly to Beijing three or four days before their scheduled events.

"As many sports have said, China presents difficulties for athletes going in and being there for a period of time," Athletics Australia national performance manager Max Binnington said today.

"Anything more than five or six days and they inevitably end up with some sort of respiratory problem. So that was why many of the sports who don't have to be in there early are choosing not to go in. And the outcome is that it's almost impossible to go for the opening ceremony."

Australia's triathletes will also miss the opening ceremonies for similar reasons.

"Most of our athletes have accepted the decision straight away," Binnington said.

The Australian Olympic Committee earlier said the decision was about logistics rather than health concerns.

"Most of the athletes have decided to come in later and not march," AOC spokesman Mike Tancred said.

"Generally those competing of the first day or the second day don't march, standing up for eight hours a day or so before competition isn't a medically smart thing to do," Tancred said .

The Australian women's basketball team also won't be marching at the opening, because of scheduling. The Australians, who won silver medals at the past two Olympics — losing to the United States each time — has a 9 a.m. game on Aug. 9 against Belarus.