GAW Report No. 205 - IGAC Project

CHAPTER 3 - ASIAEmission inventories of major air pollutantsThe emission of SO 2 and particulate matter, the vehicle number, and GDP of Shanghai overthe past years are shown as Figure 52. The emission of SO 2 seemed to be stable in the past withsmall fluctuations, even though GDP was growing. However, emission of SO 2 has increased sincethe beginning of the 21st century. From 2003 to 2007 emission of SO 2 increased by 14.3% to 497.8kt. The emission of particles decreased gradually in past years. From 2003 to 2007, emission ofparticles decreased by 50.8% to 106 kt. In addition, the vehicle number increased dramatically withthe large growth of GDP in the last decades, especially since this century, which resulted in theincrease in emissions of NO X and volatile organic compounds (VOCs). According to the study byChen et al. [2009], the NO X emission had increased to 599.7 kt in 2007, and the vehicular emissionaccounted for 14%. More importantly, the contribution of vehicular emission to NO X in urban areaswas much larger than that of the whole city, accounting for 40.8%. Obviously, vehicular emission isthe largest source of NO X in urban area of Shanghai. The VOCs emission was 597.4 kt in 2007 andvehicle emissions accounted for 14.5%, whereas in the case of urban area, the vehicular emissionaccounted for 18.8%.Figure 52 - Variation of emissions of SO2 and particles, the vehicle number, andGDP in Shanghai from 1991 to 2007 [Municipal Environmental Protection Bureau,The communiqué on the Environmental Status of Shanghai City, 1991~2008]Based on the study by Chen et al. [2009], the major SO 2 emission sources are power plants,dispersed combustion processes of industry, and industry furnaces, accounting for 46%, 27%, and10%, respectively. Similar to SO 2 , power plants are also the most important source of NO X (34%).Dispersed combustion processes of industry and vehicle emissions contribute 18% and 17% to thetotal NO X emissions, respectively. In the case of PM 10 , the largest source is dust resuspension frommotorways, accounting for 44%, followed by uncovered yard, dispersed combustion processes ofindustry, and power plants. Additionally, solvents and other product contributes the largest portionof the VOC emissions, accounting for 28%, followed by industrial processes, 23%, and vehicleemissions, 15%.In summary, power plants, industry, and vehicular emissions are the major sources of airpollutants in Shanghai and the contribution of vehicular emissions to NO X and VOCs emissions ismuch larger in urban area than in rural area. Beside these pollution sources, dust is one of the mostimportant sources of PM 10 .The ambient air qualityThe profile of annual average concentrations of SO 2 , NO 2 , CO, and PM 10 in Shanghai from2002 to 2007 is shown in Figure 53. The SO 2 annual average concentration was lower than thenational ambient air quality standard (NAAQS) for SO 2 at grade II (60 µg m -3 ) during these six years.120