Up to now this year, the city has continued to intensify its efforts against pollution, and its air quality in the first six month ranked 9th among the 168 key cities in China. The water quality index ranking of the city, among the 339 prefecture-level and above cities in the country, was 21st. Between January and July, the average concentration of PM2.5 in the city was 21 micrograms per cubic meter, down by 4.1% year-on-year; with a proportion of good air quality days at 96.7%, up by 0.9 percentage points year-on-year; all three indicators - concentration, reduction rate, and proportion of good days - ranked first in the Anhui Province.