From Los Angeles Times (link):
Desert winds have dumped 300,000 tons of sand and dust on the Chinese capital this week, turning gray rooftops yellow and forcing residents to wear surgical masks. But officials said Thursday they were confident nature would not disrupt plans to host environmentally “green” Olympic Games in 2008.
“The Olympics will be in August; the sandstorms usually hit Beijing in the months of March, April and May,” said Liu Tuo, deputy director of the Chinese State Forestry Administration’s sandstorm-control agency, at a news briefing. “Even if there are sandstorms in 2008, we have reason to be confident that the situation will not be as severe as it is now, because we are making efforts to improve the situation and they should be paying off.”
See also BBC News’ “Sandstorms choke Beijing“:
Beijing was hit by choking sandstorms on Wednesday, whipped up by high winds. Pedestrians donned masks and fled for shelter and there were traffic delays as thick dust reduced visibility.