China has imposed strict air quality targets through liability papers signed on Tuesday by the Ministry of Environmental Protection and 31 provincial regions to reduce the intensity of main air pollutants by 5 to 25 percent annually.

The paper tables specific tasks for the reduction of air pollution indicators. Beijing, Tianjin and Hebei Province were given the toughest PM2.5 reduction task of 25 percent decrease per year.

The provinces of Jiangsu, Zhejiang, Shandong and Shanxi, and Shanghai, will have to cut the indices by 20 percent, followed by 15 percent for Guangdong and Chongqing and 10 percent for the Inner Mongolia Autonomous Region.

The liability paper can ensure that local government would seriously enforce pollution control measures and set quantitative goals, said Meng Wei, dean of the Chinese Research Academy of Environmental Sciences.

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

"It's inevitable that some regions will have to sacrifice GDP growth to achieve these goals," Meng said.

China is well behind on four environmental targets set for 2015, according to a report submitted in December to the Standing Committee of the National People's Congress.

The four targets are carbon dioxide emissions, energy intensity, nitrogen oxide emissions and rationalization of energy consumption, according to the mid-term evaluation report on the implementation of the 12th Five-Year Plan (2011-15).

The report describes the issue as "grave" as pollution is widely spreading and causing greater damage. It also says that about 60 percent of Chinese cities fall below the air quality standard.

Chen Zhu, former health minister, published an estimate that air pollution causes 350,000 to 500,000 premature deaths in China a year in The Lancet medical journal in December with three other authors.

Xia Guang, director of the Policy Research Center for Environment and Economy under the Ministry of Environmental Protection, believes that the proposed targets are set in accordance with each region's current state and they will be raised even higher to upgrade the pollution fight.

The State Council is mulling a system to evaluate each provincial-level government's performance, and those failing to achieve their goals will be named and shamed. They will have to provide explanations and make corrections, said the Ministry of Environmental Protection.

Hainan and Yunnan provinces and the Tibet Autonomous Region, where air pollution is relatively low, did not receive specific tasks but were asked to make "continuous improvement." Other regions were ordered to cut their PM10 readings by 5 to 15 percent.