Beijing was one of the 10 Chinese cities with the worst air quality in July, according to a ranking released by the Ministry of Environmental Protection (MEP) on Monday.

Nearly 65 percent of July days were polluted in the capital, with one day of heavy pollution, and the main pollutants were ozone and PM2.5, showed the monthly report, which reviews air quality in 74 cities.

Six cities in Beijing's neighboring Hebei Province, including Xingtai, Tangshan, Baoding, Handan, Hengshui and Langfang, were among the ten most polluted, together with Jinan in Shandong Province, Zhengzhou in Henan Province, and the southwestern city of Chengdu.

Eight of the 74 cities reported air pollution for more than half the month. They included Xingtai, Jinan and Hengshui.

Air quality in the Beijing-Tianjin-Hebei region in July was worse than the month before, although it had improved yea on year, the report said.

The MEP also named the 10 cities with the best air quality in July. All in southern China, they included Haikou, Lishui, Fuzhou, Jiangmen, Zhuhai, Zhoushan, Xiamen, Huizhou, Zhongshan and Shenzhen.