Nanjing in Jiangsu province has realized 256 good air quality days to date this year, or a good air quality day ratio of 73.6 percent, achieving the provincial environmental protection assessment goal - 70 percent good air quality days for 2017- half a month in advance, according to Jiangsu media on Dec 14.
As for the air quality day classification at various levels in recent three years, the number of excellent air quality days greatly increased from 32 days in 2015 to 62 days in 2017, which almost doubled, and the number of heavy pollution days sharply decreased from 10 days in 2015 to one day in 2017.
In addition, the average annual fine particulate matter (PM2.5) concentration in the air in 2017 is 38 micrograms per cubic meter, a drop of 48.6 percent from the same period in 2013.
