The Chinese capital, Beijing, was shrouded in thick brown dust on Monday as heavy winds blew in from the Gobi Desert and parts of northwestern China, in what the meteorological agency has called the biggest sandstorm in a decade.
The China Meteorological Administration announced a yellow alert in the morning, saying sandstorms had spread from Inner Mongolia into the provinces of Gansu, Shanxi and Hebei, which surrounds Beijing.
Beijing-based conservation expert Zhou Jinfeng told the Associated Press the sandstorm was caused by heavy winds from Mongolia and Inner Mongolia blowing the desert’s fine particles into the capital overnight, turning the air a hazy yellow color.
State media report Beijing's official air quality index reached a maximum level of 500 on Monday morning, considered well beyond the point where the air is hazardous to human health.
The city’s environmental monitoring center said floating sand particles known as PM10 rose beyond 8,000 micrograms per cubic meter in some districts. The World Health Organization recommends average daily PM10 concentrations of no more than 50 micrograms.
Beijing faces regular sandstorms in March and April due to its proximity to the massive desert as well as deforestation and soil erosion throughout northern China.