Four United States track athletes brief the media on why they donned protective face masks upon arriving in Beijing.
Choking smog has been among the controversial elements athletes have had to battle at this year's Games. Intense heat and torrential rain have also caused problems. Beijing is a city which has been under the world's watchful eye due to its much-publicised pollution. The athletes have since apologised and now they've explained in public why they decided to wear the masks.
Neena Dhaun reports.
