Distributions, contamination level and ecological risk of heavy metals in surface sediments from intertidal zone of the Sanmen Bay, East China

Abstract

The concentrations of heavy metals, total organic carbon and total phosphorus were analyzed to assess the environmental pollution characteristics, ecological risk levels, and possible sources of heavy metals in the surface sediments from the intertidal zone of Sanmen Bay. The mean concentrations of As, Cd, Cr, Cu, Hg, Pb and Zn were 14.3 ± 1.4, 0.112 ± 0.018, 84.8 ± 6.0, 40.7 ± 4.4, 0.067 ± 0.008, 30.5 ± 3.3, and 116 ± 1.6 mg/kg dry weight, respectively. The contamination factors and ecological risk assessment indicated that the intertidal zone of Sanmen Bay is not currently facing ecological risk of studied heavy metals. The results of Pearson's correlation and principal component analysis showed that Cd, Cr, Hg, and Pb may be mainly derived from natural inputs, and hydrodynamic condition and organic matter content have major effects on the distribution of heavy metals. However, As, Cu and Zn could come from both natural and anthropogenic sources.