Variations on the Concentration of Dissolved Gaseous Mercury(DGM) at the Juam Reservoir, Korea

The reduction of in the aqueous phase results in the production of dissolved gaseous mercury(DGM), and the volatilization of DGM has been identified as an important mechanism for the loss of Hg from waterbodies to the atmosphere. Although mercury emission in the world is known to be mostly from Asia, there have been few studies of measuring DGM concentrations in lakes in Asia. In this study, DGM concentrations were measured at Juam reservoir(), Korea. The results showed that the average concentrations of DGM at the upper and down stream of the lake during summer time were pg/L, respectively and the concentration of total mercury(TM) at the upper and down stream was ng/L respectively. Average DGM concentration during summer time() was approximately 5.5 times higher than that during fall(). The DGM concentrations ai the midstream decreased from 32 to 13.7 pg/L during rain event, while the TM concentrations increased from 2.2 ng/L to 2.7 ng/L indicating the deposition of mercury from the atmosphere. Also, the diurnal patterns between DGM concentrations and UV intensities were observed. Water temperatures and DOC concentrations were significantly related to DGM concentrations, while TM concentrations were negatively related to DGM concentrations(p at Juam reservoir were approximately 3 and 2.2 times higher than those measured in other lakes(DGM: , TM: ).