[Variation analysis of background atmospheric pollutants in North China during the summer of 2008 to 2011].

In order to understand the change of background concentration of air pollutants with the development of economy in the region of North China, the concentrations of NO(x), O3 and PM2.5 were monitored during the summer of 2008 to 2011 at Xinglong station, which is the regional background station of North China. The results indicated that the average concentration of NO(x) in the summer of the four years was (9.1 +/- 5.1), (5.9 +/- 2.6), (12.2 +/- 4.6) and (14.1 +/- 5.0) microg x m(-3), respectively, the daily maximum hourly concentration of O3 was (163.3 +/- 42.7), (175.2 +/- 48.8), (199.6 +/- 52.6) and (207.2 +/- 62.1) microg x m(-3), respectively, and the average concentration of PM2.5 was (59.8 +/- 44.6), (44.4 +/- 28.0), (58.1 +/- 34.2) and (52.5 +/- 36.7) microg x m(-3), respectively; in which, the concentrations of atmospheric pollutants had increased most significantly in 2010, especially the concentration of NO(x). The average concentrations of NO(x), O3 and PM2.5 increased by 106%, 14% and 31%, respectively, compared to those in the summer of 2009. Because of the increase in the number of motor vehicle and the fast development of industry in the region of North China in 2010, the background concentrations of atmospheric pollutants were increasing obviously. The atmospheric oxidizer has also increased, the concentration of O(x) reached (155.3 +/- 40.2) microg x m(-3) and has increased by 20% compared to the average concentration of the period during the summer of 2009, the compound pollution of high concentration of ozone and fine particles becomes more and more serious in North China.