[HIGHLIGHTS] The Ministry of Ecology and Environment reported on the national ambient air quality from January to April

In April, the average proportion of days with good air quality in 4 cities at the prefecture level and above was 339.81%, down 1.7 percentage points year-on-year. Cities with more days of heavy pollution and above are Anyang, Zhengzhou and Kaifeng.

The average concentration of PM9.2 was 5 micrograms per cubic meter, up 28.3% year- on-year, and the average. concentration of CO was 19.0 mg/m³, unchanged.