Smog threat remains; Beijing issues first ever orange alert
Beijing issues orange warning for the first time as reduced visibility disrupts transport systems
As thick smog choked the capital and many mainland cities for a third straight day, Beijing yesterday issued its first-ever orange fog warning - indicating that visibility was less than 200 metres.
The conditions disrupted air traffic, forced the closure of several highways and sent countless residents scrambling for their surgical masks.
Air-quality readings released by the capital's municipal environmental monitoring centre showed the level of health-threatening PM2.5 particles, or those smaller than 2.5 microns, was 500 in the south of the city, or the upper limit of the scale. In the northern part, the level reached 440, meaning the air quality was a threat to health.
The US embassy's pollution data, published hourly on Twitter, said the PM2.5 level around the embassy was highest at 1pm, when it reached 446, or a "hazardous" level.
Yet the readings still paled in comparison to Saturday's levels, when the PM2.5 reading reached 886 micrograms per cubic metre, according to the embassy's "BeijingAir" Twitter feed.
Meteorologists in the city have forecast that the cloud of haze will linger until Wednesday, when strong winds are expected to blow the pollutants away.
The China National Environmental Monitoring Centre recorded air pollution levels in 33 cities across the country. Changsha , the capital of Hunan , issued a red warning, the highest, as visibility dropped to less than 50 metres.