On May 14, 2015, Hunan Provincial Department of Environmental Protection released the ranking list of urban air quality for the 14 cities of Hunan province. Followed the “ambient air quality standards”, the comprehensive index of Chenzhou city’s air quality of April was 4.6. 29 days well met the standards, ranking the 4th place of Hunan province.

According to the record of Chenzhou Municipal Department of Environmental Protection that 24 days of April were with good air condition, which was 3days more than March; one day of April was out of limits as mild contamination, but no severe contamination day; and the proportion of days out of limits was 3.3% which was 0.1% lower than last month. 17days of April were with the major contaminants of PM2.5, while 4days were PM10 and 4days were O3-8h (refers to maximum ozone 8hours average)