Study of heavy metal pollution, ecological risk and source apportionment in the surface water and sediments of the Jiangsu coastal region, China: A case study of the Sheyang Estuary

The concentrations of seven heavy metals in the surface water and sediments from the Sheyang Estuary were investigated to determine their spatial distribution, source apportionment and the potential ecological risks. The relative concentrations of heavy metals in the sediments were ranked as follows: Zn > Cr > Cu > Pb > As > Cd > Hg. The majority of the average concentrations of heavy metals in the sediment were higher than their background values, except for Cr and Hg, whereas the surface water heavy metals concentrations were lower. All of the elements apart from Cd indicated that there was no contamination and a low degree of pollution overall. Moreover, the heavy metal levels generally indicated low ecological risks, except for Cd. The results showed that Cu, Pb, Cr and Cd are influenced significantly by anthropogenic activities. Therefore, it is necessary to control heavy metal contamination caused by anthropogenic activities in the study area.