Ozone and fine-particle pollution worsened China's air quality in August compared with July, the Environmental Protection Ministry reported on its website on Tuesday.

Twenty-eight of the 74 cities mentioned in the report had good air quality for at least 24 days in August. The number of such cities in July was 36.

Nationwide, the proportion of days with good air quality in August was 66.7 percent, 4 percentage points lower than in July.