Seventy of 74 Chinese cities monitored nationwide suffered from air pollution in the third quarter of this year, the environmental watchdog announced Wednesday.
Five cities failed to meet the standards set by the Ministry of Environmental Protection 50 percent of the 92 days in the third quarter, said Luo Yi, head of the ministry's environment monitoring department.
Seven cities in Beijing's neighboring Hebei Province, including Xingtai, Tangshan, Baoding, Handan, Hengshui, Langfang and Shijiazhuang were among the ten most polluted, together with Jinan in Shandong Province, Zhengzhou in Henan Province, and the southwestern city of Chengdu.
The ministry said ozone overtook PM2.5 to become the main air pollutant in 74 Chinese cities from July to September.
In Beijing, nearly 46 percent of the 92 days were polluted, with three days of heavy pollution, and the main pollutants were ozone and PM2.5, said the report.
Residents in Shanghai and Guangzhou experienced better air quality in the three months, with unpolluted days accounting for 73.9 percent and 79.3 percent, respectively.
The Beijing-Tianjin-Hebei area and the Yangtze River Delta region witnessed less polluted days in the third quarter while the Pearl River Delta region did not see much change in the number of polluted days, the ministry said.
The ministry also named the 10 cities with the best air quality during the period, which were Haikou, Zhoushan, Fuzhou, Xiamen, Lishui, Zhuhai, Lhasa, Taizhou, Huizhou and Shenzhen.