The sustained southern wind helped guard the south of the Beijing-Tianjin-Hebei region against the air pollution that started to hit the mountainous areas in the central part of the region on Thursday.

The weak wind, high humidity and temperature inversion led to the accumulation of pollutants in the central parts of the Beijing-Tianjin-Hebei region, Zhang Yuanhang, an academician of the Chinese Academy of Engineering, told Beijing News.

By 8 am on Saturday, 10 of the cities in municipalities of Beijing and Tianjin and provinces of Hebei, Shandong and Henan recorded above-standard PM2.5 concentration, with a peak PM2.5 concentration of 150 micrograms per cubic meter recorded in Shijiazhuang in Hebei on Friday.

The heating by thermal power started earlier this month, the sustained operation of coking and iron and steel plants, and more movements of trucks and engineering vehicles intensified the pollution.

With the multiple cold airs arriving on Sunday, the air pollution is expected to shift from the northern and central parts of the region to the southern part and to ease in the entire region on the coming Sunday.