Northern region hit by ozone pollution

Heavy air pollution, with ozone being the primary contaminant, blanketed the Beijing-Tianjin-Hebei region on Friday.

A weak cold front is expected to arrive during the weekend, improving air quality in the region, the Beijing environmental protection authority said. But some areas will still face moderate levels of pollution, mainly caused by ozone and PM10 particulate matter.

The National Meteorological Center issued a yellow alert on Friday for high temperatures, the least serious in a three-tier warning system, with some northern provinces expected to see temperatures above 35 C and some areas experiencing heat up to 39 C.