The Dynamic Characteristics And Influencing Factors Of Main Pollutants In Beijing During The Beijing Olympic Games

In this study, the fluctuation of ambient air quality, the characteristics of air pollution and the factors influencing atmospheric pollutants were analyzed during the 2008 Olympics using the data from long-term monitoring stations based on manual monitoring technique in Beijing. The objective of this study is to offer recommendations for controlling the air pollution and improving the air quality in Beijing. The main results and conclusions as followed:(1) The air quality was relatively improved during the Olympics, and the daily average concentration of PM2.5, SO2, NOx, O3, CO both has reached the national standard.(2) The concentrations of air pollutants were substantial reduced. The concentrations of PM2.5, SO2, NOX, CO and O3 were 0.091,0.032,0.693,0.055 and .0.041 respectively before the Olympics,0.065,0.041,0.901,0.026 and 0.077 during the Olympics, and 0.071,0.079,4.440,0.037 and 0.055 after the Olympics. The airborne particulate matter has decreased 28%. The concentration of SO2 has reduced considerably. However, the O3 concentration was higher from june to October due to the photochemical reaction stronger in summer.(3) The diurnal variation of the pollutants during the Olympic Games was roughly the same compared with the time before and after Olympic Games. The variation of PM2.5, NOx, CO, SO2 showed two peaks. The first peak appeared in 7:00 to 10:00 am. The date from the monitoring points of Ecological center and Teaching Garden showed the concentration of PM2.5 has the lowest value at 13 o'clock. On the contrary, the date from the Olympic Park showed the lowest value appeared at 14 o'clock. The date from three monitoring point showed the concentrations of NOx, CO reduced from 12:00 to 18:00 o'clock, and reached the lowest point at 15:00 to 16:00 o'clock, and then rose slowly. The concentration of SO2 reduced from 12:00 to 17:00 o'clock. The second peak was appearing around 18:00 to 23:00 in night. However, The O3 showed a single peak. the concentration of O3 was usually stable before 7:00 o'clock. The date from the monitoring points of Olympic Park and Teaching Garden showed the lowest value occurred at 6:00 o'clock, while the data from ecological monitoring points showed that happened at 7:00 o'clock. The value would rose slowly, and then will reached the highest ponit at 13:00 o'clock. These results showed the control measures of air pollution were not significant effect for the daily variation.(4) The impact of meteorological conditions will be changed related to the type of the air pollutants. There was the typical summer weather with low wind velocity, high temperature and humidity during the Olympics. The concentrations of NOx, CO, SO2, were not significant correlated with the meteorological conditions. PM2.5 was significant correlated with the atmospheric pressure and the total radiation, while O3 have significant correlation with the temperature and the relative humidity.(5) The interim control measures of air pollution, and the commitment was achieved commendably.