In the country's latest effort to combat pollution, the 31 provincial-level regions of the Chinese mainland have been set targets to reduce major air pollutants by 5 to 25 percent.

Among provincial-level regions, 11 were given goals for reducing PM2.5, including an annual 25-percent decrease, the highest, for Beijing, the neighboring Tianjin Municipality and Hebei Province, according to a liability paper signed on January 7 by the regions and the Ministry of Environmental Protection.

PM2.5 refers to airborne particles less than 2.5 microns in diameter, making them small enough to pass into the gas exchange region of the lungs.

The paper also urged the regions to take measures such as reducing coal consumption, eliminating outdated industrial capacity and tightened management and control of heating boilers, vehicles and dust.

Local governments have been ordered to map out detailed plans to ensure the implementation of various anti-pollution methods and lay down specific goals for each year.

Meanwhile, the State Council, China's Cabinet, is planning a system of evaluation for each provincial-level government's progress, with those failing to reach their goals to be named and shamed.

A government report released in December 2013 revealed that progress in China's four environmental targets was lagging, including carbon dioxide emissions and energy consumption. In the relatively more polluted north China, 58 days of heavy air pollution were reported last year, roughly one out of every six.