China has witnessed a steady improvement in its air quality over the past decade, with PM2.5 density, a key indicator of air pollution, dropping by 54 percent from 2013 to 2023, authorities said Thursday.

Over the past decade, the number of days with heavy pollution has also been reduced by more than 80 percent, and in 2023, the PM2.5 density averaged 30 micrograms per cubic meter in China, said China's Ministry of Ecology and Environment at a theme activity of the International Day of Clean Air for Blue Skies held by the United Nations Environment Programme China Office.

In 2019, the United Nations General Assembly adopted a resolution to designate Sept. 7 as the International Day of Clean Air for Blue Skies, to be observed starting 2020, acknowledging an urgent need to raise public awareness at all levels and to promote and facilitate actions to improve air quality.

The Chinese central government invests more than 30 billion yuan (about 4.23 billion U.S. dollars) in air pollution prevention and control each year, with cumulative investment in recent years exceeding 200 billion yuan, driving the investment of the whole society to reach 1 trillion yuan, said Li Wei, an official with the ministry.