[Distributions of dissolved inorganic mercury in the lower part of the Three Gorges Reservoir].

One year after the first filling stage of the Three Gorges Reservoir(TGR), dissolved inorganic mercury (Hg(DI)) was measured in August 2004. Concentration of Hg(DI) varied from undetection to 82.6 ng x L(-1) with average of 22.7 ng x L(-1). Stratification of Hg(DI) in the TGR was obviously. Concentrations of Hg(DI) were much higher in the layers above 20 m than in deep waters. Concentration of Hg(DI) in the Xiangxi River varied from undetection to 61.4 ng x L(-1) with average of 18.0 ng x L(-1). The Hg(DI) concentration increased obviously after the filling of the TGR. Large amount of Hg was retented with the deposition of sediment in the TGR. The retention of Hg by the TGR needs the further research.