Long-term Trend of Sulfur Dioxide Concentration by District in Korea

Abstract The annual mean concentration of sulfur dioxide has been less than 10 ppb since 2002 in all 16 districts in Korea, but still higher than those in developed countries. In order to further reduce the sulfur dioxide concentration, it would be essential to develop a management plan that refects local characteristics of major factors determining the sulfur dioxide concentration in each district. A strategy to increase the resolution of sulfur dioxide measurement results from the monitoring stations would be also needed. Seasonal diferences of sulfur dioxide concentration in districts in Korea have decreased, and this change is expected to give an effect on the sulfate concentration. In Seoul, there is a possibility that the effect of local emission decreased and the external effect increased with the increase trend of the sulfur dioxide concentration of per sulfur oxides emission per unit area. And it was considered that the control policy of sulfur dioxide could be helpful in the management of high concentration of PM_2.5 occurrence.