China environmental monitoring station recently announced in 2013 in Beijing, Tianjin, the Yangtze River Delta, the Pearl River Delta region and municipalities, provincial capital cities and cities in the air quality situation of the city of 74. July, Xining excellent days for 27 days, air quality excellent rate of 87.09%, is the best month of air quality this year.
"list" shows that compared with June, 74 city July compliance days proportion increased by 6.3 percentage points, the number of days of severe pollution and severe pollution days ratio decreased by 3.2 percentage points and 0.4 percentage points, the concentration of major pollutants PM2.5, PM10 decreased. According to the comprehensive evaluation of urban air quality index, Xining ranked fifty-second in the northwest region of the 5 cities in Yinchuan, Urumqi, ranked in the top third. It is worth mentioning that, in July the Xining ambient air composite index was 3.29, the lowest since this year the air environment composite index.
it is understood that, in July, Xining air quality is good, good days to 27 days, but in contrast to the national air quality of the 74 cities is poor. Members of the public can not help but ask: in July, the temperature is not high in Xining is not low, the weather is good, why is the air quality rankings? This is because after the fog and haze of the beginning of the year, the overall improvement of the overall air quality in large and medium cities in most cities in the case of good weather, the air quality based on the natural. (author: Zhao Junjie)