BEIJING — Air quality in Chinese cities improved in April, according to the Ministry of Ecology and Environment (MEE).

For 339 cities monitored by the ministry, the share of good air quality days stood at 92.5 percent last month, up 3.8 percentage points year-on-year, MEE data showed.

The average PM2.5 density, a key indicator of air pollution, dropped by 15.2 percent year-on-year to 28 micrograms per cubic meter, and the average density of PM10 shrank 11.3 percent year-on-year to 55 micrograms per cubic meter.

The Beijing-Tianjin-Hebei region and the neighboring area saw their share of good air quality days increase by 4.4 percentage points to 84.5 percent last month.

In the first four months, the share of good air quality days stood at 83.8 percent, down 0.9 percentage points, while the average PM2.5 density dropped by 2.4 percent to 41 micrograms per cubic meter.