Assessment of Heavy Metal Contamination in Sediments along the Jiangsu Lagoon

摘要

In this study we have worked on the evaluation of heavy metal contamination in the sediments taken from the Jiangsu lagoon and thereby used the Enrichment factor (EF),Pollution load index (PLI),Geoaccumulation index (Igeo),Potential ecological risk index (PERI),Potential ecological risk index (PERI),Potential toxicity response index (PTRI) and Risk assessment code (RAC) and the methods of statistical analysis.The average EF of Zn is found to be less than 2,and the average EF of Cu,Cr,Cd,Pb and Ni are found to be greater than 2 in Jiangsu lagoon.The EF for Pb,Cd and Cr are higher along the Jiangsu lagoon and harbor,which reveals the anthropogenic contribution to the increased content of the surface sediments of the Jiangsu coast.PLI values calculated for Yancheng suggest that this zone is appreciably less impacted by metal pollutants than Nantong.Zn (Igeo(mean)＜0),as unpolluted to moderately polluted with Cu (0＜Igeo(mean)＜1),moderately polluted with Ni (1＜Igeo(mean)＜2),moderate to strongly polluted with Cd (2＜Igeo(mean)＜3),and strongly polluted with Cr and Pb (3＜Igeo(mean)＜4).The potential ecological risk indices ofCu,Zn and Ni in 9 stations in Lianyungang coast were lower than 40,which indicated slight potential ecological risk of three metals in 9 stations.Potential ecological risk indices ofCu,Zn and Cd in 9 stations in Yancheng lagoon were lower than 40,which indicated slight potential ecological risk of two metals in 9 stations.The sediments show a medium risk for Cu with PERI value greater than 40 indicating a moderate risk from sediments across the entire Nantong region.The amount of Cu and Ni with low risk,while Cd with moderate,with high risk in Lianyungang coast.Cu,Zn and Cd with low risk,while Cr and Ni with moderate risk,but,the Pb with very high risk in Yancheng coast.Cu and Zn with low risk,Cr and Ni with medium risk,Pb,Cd with high risk in Nantong coast.