An air quality report from the Ministry of Environmental Protection ranked Handan, Baoding and Shijiazhuang in Hebei and Zhengzhou in Henan as the top four most-polluted cities among 120 monitored nationwide.

The Air Pollution Index in the four cities reached 500, the maximum on the index, on Friday. An API reading below 50 indicates excellent air quality, 50 to 100 indicates healthy air, and readings above 100 mean polluted air.

The bad weather is expected to continue, with cold fronts expected in mid-January, Ma Xuekuan, chief weather forecaster at the National Meteorological Center, told China Daily on Friday.

“Recent wet air, increasing pollutants and little wind mean haze formed easily. When cold snaps bring winds, haze and fog will be blown away,” Ma said.

The haze brought traffic problems in Henan, with eight expressways in the province closed on Thursday because visibility was below 200 meters. No accidents or casualties due to the haze have been reported so far.

via Fog, haze lead to big spike in pollution levels – China.org.cn.