International Olympic Committee (IOC) President Jacques Rogge (R) shakes hands with Qi Liu, President of the Beijing Olympic Organising Committee (BOCOG), during the opening of the Convention of the World Sports and Environment in Beijing October 25, 2007. Beijing's air pollution remains a concern for the 2008 Olympics, even though the city is well on its way to fulfilling the environmental pledges made when it bid to host the Games, a United Nations report said on Thursday. Air quality has been one of the biggest issues facing the organisers of next August's Games, and International Olympic Committee (IOC) chief Jacques Rogge said in August that some endurance events might have to be rescheduled if the pollution was too heavy. REUTERS/David Gray (CHINA)