Vertical profiles and contamination assessments of heavy metals in sediment cores from typical intertidal zones in northern China

Abstract

The concentrations of 7 heavy metals (Cu, Pb, Zn, Cr, Cd, As and Hg) were analysed in 12 sediment cores collected from 6 typical intertidal zones in northern China. The data reveal that the environmental quality of the northern Chinese intertidal environment has gradually improved and that the concentrations of Cu, Pb, Zn, Cr, Cd, As and Hg averaged over all sediments were 29.2, 25.8, 78.5, 72.2, 0.168, 10.7 and 0.044 mg/kg, respectively. The results of the geoaccumulation index and enrichment factor methods demonstrate that most of the sediments in the intertidal zone in northern China have good environmental quality, although some areas are contaminanted, including the Yangtze River Estuary, which is seriously contaminanted. According to sediment quality guidelines, the heavy metal concentrations in the sediments in the 6 typical intertidal zones in this survey are categorized as having moderate impacts with potential adverse biotoxic effects.

Keywords: Contamination assessment; Heavy metal; Intertidal; Sediment.