On June 30, the Environmental Monitoring Center of Anhui released the air quality ranking of the province's 16 prefecture-level cities (January to May 2021), with Huangshan coming at top and Huainan at bottom. During these months, the province's average composite air quality index (composite AQI) was 4.30, and the average proportion of "good" and "moderate" air quality (AQI value 0~100) days was 85.2%.
According to the monitoring data, Huangshan, Xuancheng and Chizhou are ranked the top three cities in terms of air quality, among which Huangshan had the best air quality, with a composite AQI of 2.77, a year-on-year change rate of -3.1%, and a proportion of "good" days of 99.3%. Huainan, Fuyang and Suzhou are ranked the bottom three, among which Huainan is ranked the last place with a composite AQI of 4.88, a year-on-year change rate of 0.2%, and a proportion of "good" and "moderate" days of 76.8%.
Regarding the change rate of composite AQI, 10 cities went greater than 0, including Chizhou, Lu 'an, Wuhu, Hefei, Tongling, Maanshan, Chuzhou, Bengbu, Suzhou and Huainan, while the other 6 cities went below 0, indicating that the air quality was better than the same period last year. Bozhou saw the biggest improvement, with -7.5 percent.