BEIJING, Oct. 22 (Xinhua) -- New data has shown a steady improvement in China's air and water quality in the first nine months of this year.

During the January-September 2024 period, the average density of PM2.5 in 339 Chinese cities at or above the prefecture level stood at 27 micrograms per cubic meter, down 3.6 percent year on year, Pei Xiaofei, spokesperson for the Ministry of Ecology and Environment, told a press conference on Tuesday.

The proportion of days with good air quality in these cities during this period was 85.8 percent, up 1.6 percentage points from the same period last year, Pei said.

Pei added that 88.5 percent of monitored sections had "fairly good" surface water quality -- at or above Grade III in the country's five-tier water quality system, an increase of 1.4 percentage points year on year.

The share of surface water at Grade V, the lowest level, stood at 0.7 percent, remaining flat compared with a year earlier, according to the spokesperson.

China has steadfastly advanced its "Beautiful China" initiative, emphasizing ecological and environmental protection as a top priority in its social and economic development.