Comprehensive Assessment of Heavy MetalContamination in Surface Sediments from theInflow Rivers of Taihu Basin

摘要

The spatial variation, potential sources, and ecological risk of heavy metals (Cd, Co, Cr, Cu, Mn, Hg, Ni, Pb, and Zn) in surface sediments from the typical inflow rivers in Taihu Basin were investigated in June 2010. The results showed that the heavy metal concentrations varied greatly and spatially, and higher metal contamination mainly occurred in the northern and northwestern regions in Taihu Basin. Multivariate statistical analysis demonstrated that Mn might originate from natural sources, whereas Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn were primarily delivered from anthropogenic activities. The geoaccumulation index and enrichment factor values indicated that Cd, Cu, Cr, and Zn were moderately severe enriched, Ni and Pb were moderate enriched, while Co and Hg were at a minor enrichment level, which indicated that their contamination was not a major concern in the inflow rivers of the basin. Compared with the “Consensus-Based Sediment Quality Guidelines,” Cr, Cu, Ni, and Zn were most likely to result in ecological toxicity for aquatic organisms. Although Cd was at moderately severe enrichment level, the probable effect concentration quotients of Cd<1 implied it had no or low adverse effects on organisms. The results also suggest that Cr, Cu, Ni and Zn contamination in the north and northwest of the basin should be addressed as the first priority.