Abstract
Atmospheric concentrations of sulfur dioxide (SO2) in Chinese major cities were discussed focusing on the area distribution and yearly variation during a period of 1991-1999. Atmospheric data used in this study were cited from a series of China Environmental Yearbook. While apparent increasing trends in the concentrations were not found in 66 cities, a half of the cities showed decreasing trends. This suggests air pollutions by SO2 are gradually improved in China. Although coal combustion is a major emission source of SO2, averaged atmospheric SO2 concentration of 66 cities did not significantly correlate to coal consumption data. However, reduction of coal consumption in a specific section such as household use and increase in desulfurization activities in the industrial section results in the decreasing trend of the whole SO2 concentration in China. On the other hand, spatial distribution of SO2 concentration depends on emission amounts of SO2 discharged from industry including electric power supply. Furthermore, removal rate of SO2 by desulfurization systems determines the yearly trends of atmospheric SO2 concentration at each city.
