The effects of anthropogenic sources on temporal distribution characteristics of total gaseous mercury in Korea

In order to study the fundamental factors associated with anthropogenic source processes for atmospheric Hg, we analyzed the total gaseous mercury (Hg: TGM) concentration data collected during the late 1980s in Seoul, Korea. Since the consumption amount of coal in Korea, known as the major anthropogenic source of Hg, peaked during those time periods, inspection of the data distribution provided an opportunity to assess the role of coal burning on the temporal distribution characteristics of airborne Hg. The Hg data for the 1980s were characteristic of notably high concentrations typically exceeding 10 ng m−3. When the seasonal patterns of the Hg data were examined in terms of relative frequency over varying concentration ranges, the data were consistently exhibiting signatures of two different source processes. In the lower concentration range where the effect of natural sources appear to be dominant in relative sense, Hg concentrations tend to decrease across spring through winter. On the other hand, in the upper concentration range where the effects of anthropogenic sources are important, its concentrations tend to increase from spring to winter. The signature of anthropogenic sources in the late 1980s was supported not only by the unique seasonal distribution patterns but also by the consistent occurrences of high Hg levels (e.g., >20 ng m−3) throughout seasons. On the basis of our data analysis, we may conclude that the temporal distribution patterns of Hg measured at several locations of the Seoul Metropolitan city during the late 1980s are useful enough to distinguish the signature of anthropogenic sources such as the use of anthracite.