1. Recent Studies of Urban Air Pollution over the Greater Beijing Area Meigen ZHANG (State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences) March 10, 2003

2. Basic Information – 13.8 million residents in 16807 km 2 – 27 million tons of Coal / yr – 2 million tons of low S coal – 700 million m 3 of natural gas – 1.849 million vehicles in Aug. 2002 (1.31million in 1998) – Sand storms in spring

5. Heating seasonYearly averageNo heating season Yearly average concentrations of SO 2 in the suburb of Beijing in the period of 1984-2000 Spike: 1987,1992 and 1997 Emission control: 1998--

6. Daily average concentrations of SO 2 in the suburb of Beijing in the period of 1997.01-2001.02 1. Seasonal variation 2. Effect of SO 2 emission control

7. Heating seasonYearly averageNo heating season Yearly average concentrations of NO x in the suburb of Beijing in the period of 1981-2000 Fast increase after 1989 Emission control: 1998-

8. Daily average concentrations of NO x in the suburb of Beijing in the year of 2001 NO 2 /NO x ~ 1

9. Heating seasonNo heating seasonYearly average Yearly average concentrations of TSP in the suburb of Beijing in the period of 1981-2000

10. Daily average concentrations of TSP in the suburb of Beijing in the period of 1997.01-2001.06 (unit: mg/m 3 )

11. Chemical composition of TSP sampled in a park in Beijing during the period from June 23 to July 3 of 2000

12. Daily average concentrations of PM 10 in the suburb of Beijing in the period of 1999.01-2001.06 (unit: mg/m 3 )

13. Daily average concentrations of TSP and PM10 and their ratios in the suburb of Beijing in the period of 1999.01-2001.06 PM 10 /TSP is higher in the period of May ~ October than in other time

14. The ratios of chemical composition in PM 2.5 and PM 10 in Beijing in 2000 The ratios of SO 4 2-, NO 3 -,NH 4 +,OC and EC > 0.5 Ca, Al and Fe < 0.5

15. Chemical compositions of PM2.5 in the winter and summer of Beijing 1999, 6, 13-14 1999, 6, 13-14 118.19 ug/m 3 Pollution caused by organic compounds becomes severe

16. PM2.5 and its chemical compositions Dongsi and PKU sites, January 20, 2000 Peking Univ. 66 ug/m 3 Pollution caused by organic compounds becomes severe Dong Si 55 ug/m 3

17. Days (left plot) and hours (right plot) of O 3 concentrations exceeding air quality standard II in a year in Beijing during 1989-2000

18. Observed maximum O 3 concentrations in Beijing during 1989-2000

19. Observed O3 mixing ratios in the summer of 2000

20. National Air Quality Standards in China