Air pollution in Beijing could cause problems for athletes and visitors during the 2008 Olympic Games, especially those with asthma, according to the American Academy of Allergy, Asthma & Immunology.

Beijing's place among the world's worst in air quality has experts concerned. Exercise combined with pollutants can sometimes stimulate an asthma attack. The ozone, sulfur dioxide, nitric oxide and other pollutants in Beijing's hazy air can inflame the airways of sensitive people and even cause an asthma attack.

Exercise-induced asthma affects an estimated 1 in 6 of all Olympic athletes. Prescription asthma medications, including controller and rescue medication, can be used.  But due to anti-doping regulations, which restrict the use of many asthma medications at the Olympic Games, athletes must obtain official approval for many medications.