One of the main reasons for the high levels of air pollution is the traffic problem in the capital.

The city's officials aim to temporarily reduce the three million registered vehicles by one million this year.

During the test events in 2007, data will be collected to see if doing this will have an effect of air quality.

IOC chief Jacques Rogge added: "It is important to remind ourselves it is not the first time that Games have had to deal with challenges in this field."