[Determination of Background Value and Potential Ecological Risk Assessment of Heavy Metals in Sediments of the Danjiangkou Reservoir]

The aim of this study was to explore the pollution level and potential ecological risk of heavy metals in sediments of the Danjiangkou Reservoir, and the study obtained the background value of heavy metals of the surface sediments using reference element and statistical methods. The results indicated that the background values of Cr, Ni, Cu, Zn, As, Cd, Hg and Pb were 41.18, 34, 32.13, 76.84, 10.46, 0.70, 0.07 and 27.11 mg·kg, respectively. In addition, the potential ecological risks of the eight heavy metals in sediments were assessed using the Hakanson ecological risk index method. The values of RI for these eight metals in surface sediments ranged from 29.49 to 214.11, with the mean value of 118.91, and the pollution level was low. Furthermore, the value was in the order of Cd> Hg> Zn> Cr> Pb> Ni> As=Cu with the mean value of 1.05-1.31, and the pollution level varied from low to intermediate. The values of Cd and Hg were higher than those of other heavy metals with the mean values of 1.31 and 1.24, respectively, which should be paid more attentions.