Xinhua:
Beijing had its worst dusty air of the year Thursday [i.e.today], as the air quality index reached level five, the worst rating on a five-point scale.
A sandstorm swept from northwest China to Beijing at about 4:00a.m., entered the city’s urban districts one hour later and reaching its peak at 6:00 a.m.
According to air monitoring centers in the national capital early Thursday, suspended particles exceeded 1,500 micrograms per cubic meter of air…
…The environmental department advised people to stay indoors or try to reduce the time spent outdoors for the sake of their health.
LINK:
Xinhua: Beijing reports worst dusty day (in English)