A pedestrian walks amid heavy smog in Beijing, capital of China, Dec 29, 2015. [Photo/Xinhua]

Chinese authorities unveiled goals Wednesday to cut PM2.5 in the heavily polluted Beijing-Tianjin-Hebei region to 73 micrograms per cubic meter by 2017 and 64 micrograms per cubic meter by 2020, the country's top economic planner said.

By 2020, PM2.5 - unhealthy particulate matter with a diameter of less than 2.5 microns - is expected to drop by 40 percent compared to the figure in 2013, an official of the Department of Resource Conservation and Environmental Protection told a press briefing.

The safety guideline for PM2.5 set by the World Health Organization is 25 micrograms per cubic meter, whereas the Chinese government sets a limit of 75 micrograms per cubic meter.

A blueprint for ecological and environmental protection for the Beijing-Tianjin-Hebei region was released on Wednesday to reduce air, water and soil pollution in this region.