"In addition, there is such statistics: in 2016, in 74 main cities of China the average concentration of PM2.5 harmful particles for the year amounted to 50 micrograms per cubic meter, which is 30.6 percent less compared with the figures of 2013," Chen said at a press conference.
According to the standard set by the World Health Organization (WHO), the safe concentration of PM2.5 is 25 micrograms per cubic meter.
Chen stressed that the number of days with severe pollution registered had also reduced.
Earlier this month, Chinese Premier Li Keqiang said the government would undertake a number of measures to combat air pollution in 2017 and would "make skies blue again" cutting the emission of sulfur dioxide and nitrogen oxide by 3 percent and lowering the density of PM2.5. The measures would include reducing coal use and cars emissions, upgrading coal-fired power plants, encouraging the use of clean-energy vehicles and punishing government officials who ignore environmental crimes or air pollution in their designated areas.
In 2016 the environmental inspectors investigated 33,000 cases of alleged environment-related wrongdoing detaining 720 people and imposing fines totaling 440 million yuans (about $64 million).