The air of major Chinese cities saw lighter pollution in July, the Ministry of Environmental Protection (MEP) said Friday.

About 29.3 percent of the days on average in July saw air pollution in 74 major cities, including light pollution on 21.1 percent of the days, moderate pollution in 6.5 percent of the days and heavy pollution in 1.7 percent of the days, according to the MEP air quality readings.

Compared to June, the share of non-polluted days in July in the 74 cities rose by 6.3 percentage points.

Also according to the air quality readings, 17 out of the 74 cities were shrouded in pollution in over half of July, and the major pollutants were ozone and PM 2.5, or dangerous airborne particles measuring less than 2.5 microns in diameter,

Up to 63.5 percent of the days in July saw air pollution in Beijing, as well as neighboring Tianjin Municipality and Hebei Province, and the share of non-polluted days in this region increased by 12.3 percentage points month on month.

Major cities in the Yangtze River Delta region sustained air pollution in 26.5 percent of days in July.

The Pearl River Delta, a city agglomeration in south China, had good air quality for about 90 percent of the days in July.