Guiyang completed its air quality assessment for April on May 17, with the air situation in 14 districts, counties, and development zones being rated as "good", and Guanshanhu district receiving the highest rating yet again.
The rankings in April are as follows, from best to worst: Guanshanhu district, Kaiyang county, Qingzhen city, Guiyang National High-tech Industrial Development Zone, Wudang district, Yunyan district, Guizhou Shuanglong Airport Economic Zone, Huaxi district, Guiyang Free Trade Zone, Guiyang Economic and Technological Development Zone, Baiyun district, Nanming district, Xiuwen county, and Xifeng county.
The number of days in all districts, zones and counties in Guiyang with good ambient air quality ranged from 96.7 percent to 100 percent. The city's comprehensive air quality index ranged from 2.36 to 2.87.
"Good" ambient air quality refers to an air pollution index that is greater than 50 and less than or equal to 100, according to national standards.