National air quality ranking
From July 2065438 to July 2009, the average number of excellent days in 337 cities at prefecture level and above was 85.4%, down 6.9 percentage points year-on-year; The concentration of PM2.5 is 20 μ g/m3, which is flat year-on-year; The concentration of PM 10 was 40 μ g/m3, up 5.3% year-on-year. O3 concentration was 146 μ g/m3, up 8.1%year-on-year; SO2 concentration was 8 μ g/m3, down 1 1. 1% year-on-year.
20 19 July, 168 Among the key cities, 20 cities such as Tangshan, Jincheng and Xingtai have poor air quality (168 to149); The air quality in 20 cities such as Haikou, Zhuhai and Lishui is relatively good (from 1 to 20).
Air environment in Beijing, Tianjin and Hebei
The average number of excellent days in July in "2+26" cities in Beijing, Tianjin and Hebei and its surrounding areas was 38.6%, down 28.7 percentage points year-on-year, and the main pollutant was O3. The concentration of PM2.5 was 34 μ g/m3, down 2.9% year-on-year. The proportion of excellent days in July in Beijing was 38.7%, down 25.8 percentage points year-on-year, and the main pollutant was O3. The concentration of PM2.5 was 37 μ g/m3, down 15.9% year-on-year.
The average number of excellent days in July in the Yangtze River Delta region of 4 1 city was 8 1.9%, down 9.9 percentage points year-on-year; The concentration of PM2.5 was 23 μ g/m3, up 9.5% year-on-year. The average number of excellent days in Wei Fen Plain 1 1 city in July was 57.2%, down by 20.8 percentage points year-on-year, and the main pollutant was O3. The concentration of PM2.5 was 25 μ g/m3, down 19.4% year-on-year.