Ready ... get set ... choke!?

DO not adjust your eyes.

"We are going to have a bunch of American athletes Returning with chronic lung problems !"

These pictures, taken exactly 24 hours apart, graphically illustrate how Beijing has gone from beautiful one day, to choking the next.

Just three days from the Opening Ceremony, Beijing's air is clogged with lethal smog 26 times the average Sydney day, a Beijing Now investigation can reveal.

The smog was so intense it penetrated the Aquatic Centre - or Water Cube - prompting calls for an investigation by the Australian swimming team.

Tests on the atmosphere inside the Olympic Green, and within 500 metres of the Games track and field and swimming facilities, show pollution has soared in the past 24 hours to levels equivalent of a bushfire.

A haze hovering high inside above the competition pool greeted the Australian swim team for their first training session at the Olympic swimming venue.

Australian head swimming coach Alan Thompson said he was seeking an answer from event organisers at the pool to find out why it appeared the smog had crept indoors.

"I am trying to find the answer to that question,'' Thompson said when asked if he had noticed the hazy conditions.

"I don't know why, but I did notice the haze.''

The extreme readings in Beijing raise the prospect of Olympic events being rescheduled in a bid to protect athletes from life-threatening conditions.

Pollution experts said yesterday it was a case of when - not if - athletes broke down under the conditions.

And they warned more serious responses - even death - were now possible.

"You have a cocktail of conditions that add up to extreme stress on the athlete,'' said Murdoch University associate professor Peter Dingle.

"With these readings you are talking more than 20 times a high day in Sydney or Melbourne and 10 times the most extreme pollution day (in Sydney or Melbourne).,00.html