BEIJING - Tons of sand turned Beijing's sky orange as the strongest sandstorm this year hit northern China, a gritty reminder that the country's expanding deserts have led to a sharp increase in the storms.
The sky glowed yesterday and a thin dusting of sand covered Beijing, causing workers and tourists to muffle their faces in vast Tiananmen Square. The city's weather bureau gave air quality a rare hazardous ranking.
Air quality is "very bad for the health," China's national weather bureau warned. It said people should cover their mouths when outside and keep doors and windows closed.
China's expanding deserts now cover one-third of the country because of overgrazing, deforestation, urban sprawl and drought.
The shifting sands have led to a sharp increase in sandstorms - the grit from which can travel as far as the western United States.
The Chinese Academy of Sciences has estimated that the number of sandstorms has jumped sixfold in the past 50 years to two dozen a year.
The latest sandstorm also hit the regions of Xinjiang and Inner Mongolia and the provinces of Shanxi, Shaanxi and Hebei, affecting about 250 million people over an area of 312,000 square miles, the state-run Xinhua News Agency reported.
As the sandstorm moved southeast, South Korea's national weather agency issued a yellow dust advisory for Seoul and other parts of the country.
Skies cleared in the city by midday, but a warning of more dusty weather remained in place until early this afternoon.
China has planted thousands of acres of vegetation in recent years to stop the spread of deserts in its north and west, but experts have said the work will take decades.
"The challenges ahead are still huge," China said in a report to the United Nations in 2006.