China on Wednesday set new targets to reduce air pollution in the Beijing-Tianjin-Hebei region, vowing to reduce the yearly average benchmark PM2.5 level to 73 micrograms per cubic meter by 2017.

China also plans to reduce the yearly average PM2.5 level in the region to 64 micrograms per cubic meter by 2020, a 40 percent drop from the level in 2013.

The average PM2.5 level in the Beijing-Tianjin-Hebei region in 2013 was 106 micrograms per cubic meter.

PM2.5 refers to particles with a diameter of or less than 2.5 micrometers, which can easily penetrate lungs.

The target was part of the new "Beijing-Tianjin-Hebei synergetic development and ecological environmental protection plan" released Wednesday.

The official document of the plan has not been released and no other information was available as of press time.

Zhang Yuanxun, a professor of environmental sciences at the Chinese Academy of Sciences, told the Global Times on Wednesday the new targets were "ambitious" and "a tough decision" for the authorities.

"Given the rising number of automobiles and the increasing population, maintaining the current pollution level alone will be difficult enough," Zhang said.

He noted that the government may try to enforce the environmental regulations more strictly and impose more bans on urban traffic.