Eight cities surrounding Beijing and its neighbors Tianjin and Hebei province, were listed on the worst 10 Chinese cities for air quality in February, the Ministry of Environmental Protection said on Tuesday.

The largest contributor to the region's air pollution is PM 2.5, according to the ministry.

PM 2.5 refers to particles 2.5 micrometers in diameter or less, which are considered extremely hazardous as they can penetrate lungs and other internal organs.

From Feb 20 to 26, smog enveloped 15 provinces and regions, covering more than 1.8 million square kilometers, data from the ministry showed.

While Beijing and its neighbors suffered a smoggy February, seven cities including Kunming, Yunnan province; Haikou, Hainan province; and Shenzhen, Guangdong province met the national air-quality standards last month.