SHENZHEN’S air quality in May was ranked fourth out of 168 key cities in the country, according to a report released by the Ministry of Ecology and Environment recently.

The 339 cities at the prefecture level and above in the country enjoyed good air quality on 85.2% of the days in May, down 2.6 percentage points year on year. Their average PM2.5 concentration, a key gauge for air pollution, was 22 micrograms per cubic meter, at the same level as the same period last year. The average PM10 concentration was 45 micrograms per cubic meter, down by 4.3% year on year.

The top 10 cities with good air quality in May are Haikou, Lhasa, Guiyang, Shenzhen, Huizhou, Zhangjiakou, Zhoushan, Zhuhai, Lishui and Huangshan.  (Xia Yuanjie)