The Ministry of Ecology and Environment reported on June 19 the national ambient air quality status in May and January-May.
In May, the average proportion of days with good air quality in 339 prefecture-level and above cities across the country was 88.3%, an increase of 3.1 percentage points year-on-year; the average proportion of days with heavy pollution and above was 0.6%, an increase of 0.1 percentage points year-on-year; PM2.5 The average concentration was 23 μg/m3, a year-on-year increase of 4.5%; the average PM10 concentration was 46 μg/m3, a year-on-year increase of 4.5%; the average O3 concentration was 149 μg/m3, a year-on-year decrease of 2.6%; the average SO2 concentration was 8 μg /m3, flat year-on-year; average NO2 concentration was 17 micrograms/m3, down 5.6% year-on-year; average CO concentration was 0.7 mg/m3, flat year-on-year.
From January to May, the average proportion of days with good air quality in 339 prefecture-level and above cities across the country was 82.0%, a year-on-year decrease of 3.1 percentage points; the average proportion of days with heavy and above pollution was 3.0%, a year-on-year increase of 1.6 percentage points; PM2 .5 The average concentration was 38 μg/m3, up 8.6% year-on-year; the average PM10 concentration was 67 μg/m3, up 13.6% year-on-year; the average O3 concentration was 137 μg/m3, down 0.7% year-on-year; the average SO2 concentration was The average concentration of NO2 was 23 μg/m3, which was the same as the same period last year; the average concentration of CO was 1.1 mg/m3, which was a year-on-year decrease of 8.3%.
In May, the average proportion of days exceeding the standard caused by sand and dust weather in 339 cities above the prefecture level across the country was 2.8%; from January to May, the average proportion of days exceeding the standard caused by sand and dust weather was 6.3%.