Heavy smog to cloak northern China until cold front moves in

Thick smog will continue to blanket more than 20 cities in northern China over the next few days, weather authorities said on Sunday even as officials tried to limit polluting activity in an attempt to clear the air.
Beijing and its neighbouring areas, including Hebei, Henan, Shandong, Shanxi and Tianjin, would experience severe air pollution, Xinhua quoted the meteorological authorities as saying.
The warning came after Beijing issued a red pollution alert – the highest in a four-tier system – on Friday.
The smog built up as winds blew in with PM2.5 pollutants – particles smaller than 2.5 microns in diameter that can cause the greatest harm to public health.
Conditions were at hazardous levels last night.
Pollution was expected to peak on Tuesday before a strong cold front arrived to disperse it, the authorities said.