recent studies of urban air pollution over the greater beijing area

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

Basic Information

– 13.8 million residents in 16807 km2

– 27 million tons of Coal / yr27 million tons of Coal / yr– 2 million tons of low S coal2 million tons of low S coal– 700 million m700 million m33 of natural gas of natural gas – 1.849 million vehicles in Aug. 2002 (1.31million in 1

998)– Sand storms in spring

Heating season Yearly average No heating season

Yearly average concentrations of SO2 in the suburb of Beijing in the period of 1984-2000

Spike: 1987,1992 and 1997Emission control: 1998--

Daily average concentrations of SO2 in the suburb of Beijing in the period of 1997.01-2001.02

1. Seasonal variation2. Effect of SO2 emission control

Heating season Yearly average No heating season

Yearly average concentrations of NOx in the suburb of Beijing in the period of 1981-2000

Fast increase after 1989Emission control: 1998-

Daily average concentrations of NOx in the suburb of Beijing in the year of 2001

NO2/NOx ~ 1

Heating season

No heating seasonYearly average

Yearly average concentrations of TSP in the suburb of Beijing in the period of 1981-2000

Daily average concentrations of TSP in the suburb of Beijing in the period of 1997.01-2001.06 (unit: mg/m3)

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

Daily average concentrations of PM10 in the suburb of Beijing in the period of 1999.01-2001.06 (unit: mg/m3)

Daily average concentrations of TSP and PM10 and their ratios in the suburb of Beijing in the period of 1999.01-2001.06

PM10/TSP is higher in the period of May ~ October than in other time

The ratios of chemical composition in PM2.5 and PM10 in Beijing in 2000

The ratios of SO42-, NO3

-,NH4+,OC and EC > 0.5

Ca, Al and Fe < 0.5

Chemical compositions of PM2.5 in the winter and summer of Beijing

2000, 01, 20 Dosi Si te

55ug/ m3

OC51%

EC4%

SO415%

NO39%

Cl5%

Na2%

NH49%Other

5%

OC35%

EC3%

Nitrate5%

Sulfate19%

Ammonium5%

CL1%

Crustal20% Trace

1% Other11%

1999, 6, 13-14 1999, 6, 13-14

118.19 ug/m118.19 ug/m33

Pollution caused by organic compounds becomes severe

PM2.5 and its chemical compositions PM2.5 and its chemical compositions Dongsi and PKU sites, January 20, 2000Dongsi and PKU sites, January 20, 2000

Peking Univ.

66 ug/m3

Pollution caused by organic compounds becomes severe

Dong Si

55 ug/m3

OC51%

EC4%

SO415%

NO39%

Cl5%

Na2%

NH49% Other

5%

OC60%

EC3%

SO412%

NO36%

Cl3%

Na2%

NH46% Other

8%

Days (left plot) and hours (right plot) of O3 concentrations exceeding air quality standard II in a year in Beijing during 1989-2000

Observed maximum O3 concentrations in Beijing during 1989-2000

Observed O3 mixing ratios in the summer of 2000

National Air Quality Standards in ChinaNational Air Quality Standards in China

Pollutants Average First Class Second Class Third Class

SO2

Mg/m3

Yearly

Daily

Hourly

0.02

0.05

0.15

0.06

0.15

0.50

0.10

0.25

0.70

TSP

Mg/m3

Yearly

Daily

0.08

0.12

0.20

0.30

0.30

0.50

PM10

Mg/m3

Yearly

Daily

0.04

0.05

0.10

0.15

0.15

0.25

NO2

Mg/m3

Yearly

Daily

Hourly

0.04

0.08

0.12

0.08

0.12

0.24

0.08

0.12

0.24

CO

Mg/m3

Daily

Hourly

4.00

10.00

4.00

10.00

6.00

20.00

O3

Mg/m3

Hourly 0.16 0.20 0.20