China witnessed improved air pollution with lower concentrations of pollutants and fewer days with severe air pollution in 2016, the environmental authority said on Wednesday.

In 2016, the average PM2.5 concentration in the 31 provinces was lowered to 47 micrograms per cubic meter, down 6 percent from 2015, the Ministry of Environmental Protection said on Wednesday, adding that 78.8 percent of days had good air quality, growing by 2.1 percent.

The Beijing-Tianjin-Hebei region also saw improvements, such as an average PM2.5 concentration in 2016 that was 33 percent lower than in 2013.?

But the regional average PM2.5 reading, which was 71, was much higher than the national average in 2016 and double the national health standard, which is 35, it added.?

PM2.5 refers to particulate matter with a diameter less than 2.5 microns that is hazardous to human health and whose reading is used as a major index for air pollution.?

In addition, the Beijing-Tianjin-Hebei region saw 56.8 percent of days with good air quality last year.?

But in Yangtze River Delta region including Shanghai, the percentage of blue sky days was 76.1 percent, according to the statement.?