Air quality in major parts of China was better in April than in March, with dust and ozone accounting for a larger proportion among the key pollutants, according to statistics released on Friday by the Environmental Protection Ministry.

The statistics show that air quality in 74 Chinese cities met national standards 70.6 percent of the time in April, an improvement over March's 62.3 percent. The number of cities scoring above 80 percent also rose, from 22 in March to 29 in April.

In contrast with the progress made by the 74 major cities as a whole, air quality in the most-polluted area - the Beijing, Tianjin and Hebei province cluster - got slightly worse in April. Nine cities out of the 13 in this region appeared on the list of the top 10 cities with the worst air quality. The number in March was seven.