China's Ministry of Ecology and Environment released China's air quality data for 2022 on Saturday.
The share of days with good air quality stood at 86.5 percent in 339 cities across the country (including cities at and above the prefecture-level), or 316 days, according to the data.
The proportion of days with heavy air pollution was 0.9 percent, dropping to less than 1 percent for the first time, said Jiang Huohua, an official with the ministry, at a press conference on January 17.
The data shows the average density of PM2.5, a key indicator of air pollution, dropped 3.3 percent year on year to 29 micrograms per cubic meter (μg/m3), falling below 30 μg/m3 for the first time since the data was first monitored.
The average concentration of PM10, fine particle matter that contributes to air pollution, was 51 μg/m3 in the monitored cities, down 5.6 percent year on year.
In addition, the average concentration of nitrogen dioxide was 21 μg/m3, down by 8.7 percent year on year, while the average ozone concentration was 145 μg/m3, up by 5.8 percent. The average sulfur dioxide concentration was 9 μg/m3 and the average carbon monoxide concentration was 1.1 mg/m3, unchanged from the previous year.