Zhuhai had China's second-best air quality last month, just behind Haikou on the tropical island of Hainan, as they both led 169 key cities, according to the Ministry of Ecology & Environment.

The ratio of days with excellent or fine air was recorded at 79.2 percent in June for 337 cities of prefecture-level or above, down 0.1 percentage point from the same month last year. The average concentrations of PM2.5, PM10, O3 and SO2 saw respective decreases of 4.3, 4.4, 2.5 and 10 percent to 22, 43, 156 and 9 mcg per cubic meter.

Zhuhai's air quality speaks for itself [File photo]

Furthermore, Zhuhai was rated 7th in breathability in the first half of this year. Other cities that made the top 10 are Haikou, Lhasa, Shenzhen, Zhoushan, Huizhou, Huangshan, Lishui, Xiamen, and Zhongshan.

From January through June, the ratio of excellent or fine air days was 80.1 percent, up 0.4 percentage points. A total of 142 cities met national ambient air quality standards, 20 more than same period last year.

Meanwhile, the average concentrations of PM2.5, PM10, and SO2 saw a general decline of 2.4, 4.2 and 14.3 percent to 40, 69, 12 mcg per cubic meter respectively, while that of CO increased by 7.1 percent to 1.5 mcg per cubic meter.