Heavy metal pollution in sediments of Guanhe estuary in Haizhou Bay, Lianyungang

Spatial distribution of metal concentrations in the surface sediment samples collected from 19 marine at Guanhe estuary in Haizhou Bay, Lianyungang was studied. Heavy metal (Cu, Zn, Pb, Cd, Cr, As, Ni, Mn) concentrations were determined and geo-accumulation index (Igeo) was calculated to understand the pollution status of the study area based on the background values. The ranges of the measured concentrations in the sediments are as follows: 8.65–27.8 mg/kg for Cu, 215–319 mg/kg for Zn, 37.0–72.4 mg/kg for Pb, 0.55–3.45 mg/kg for Cd, 34.3–92.1 mg/kg for Cr, 30.0–51.9 mg/kg for As, 21.3–49.6 mg/kg for Ni, 430–837 mg/kg for Mn. Geoaccumulation index (Igeo) shows that Cd contamination exists in the entire study area and contamination of other metals are also present in some locations depending on the sources, of which sewage outlets and commercial ports are the main sources of contaminants to the area.