Nearly 90 per cent of China's big cities failed to meet air quality standards in 2014, but that was still an improvement on 2013, the country's environment ministry says.

Amid growing public disquiet about smog and other environmental risks, China said last year it would "declare war on pollution" and it has started to eliminate substandard industrial capacity and reduce coal consumption.

The Ministry of Environmental Protection said on its website that only eight of the 74 cities it monitors managed to meet national standards in 2014 on a series of pollution measures such as PM2.5, which is a reading of particles found in the air, carbon monoxide and ozone.

In 2013, only three cities - Haikou on the island province of Hainan, the Tibetan capital of Lhasa and the coastal resort city of Zhoushan - met the standards.

They were joined in 2014 by Shenzhen, Huizhou and Zhuhai in south-east Guangdong province, Fuzhou in neighbouring Fujian and Kunming in the south-west.

Of the 10 worst-performing cities in 2014, seven were located in the heavy industrial province of Hebei, which surrounds the capital Beijing, the ministry said.

The cities of Baoding, Xingtai, Shijiazhuang, Tangshan, Handan and Hengshui, all in Hebei, filled the top six places.

The ministry said the average PM2.5 reading in the Beijing-Hebei-Tianjin region stood at 93 micrograms per cubic metre last year.

The state standard is 35 micrograms, but China does not expect to bring the national average down to that level before 2030.

The government has identified Hebei as a top priority when it comes to cutting smog, and it has set targets to slash coal consumption and close polluting industrial capacity, but the province has struggled to find alternative sources of growth.

Reuters