Hebei province had seven cities in the top ten with the worst air pollution in August, and Chengdu, capital of Sichuan province appeared for a second successive month, the national environment authority said on Wednesday.

Handan city in Hebei was ranked worst, based on the monthly air quality reports of 74 major cities in August, released by the Ministry of Environmental Protection.

In addition, Xingtai, Tangshan, Baoding, Hengshui, Langfang and Shijiazhuang from the province with heavy industries as its economic pillars also featured in the top ten.

In spite of the devastating blast on Aug 12, Tianjin saw air quality higher than national standards for more than 80 percent of the 31 days in August, the report said.