Distribution and contamination of trace elements in surface sediments of the Yellow River Estuary and Laizhou Bay, China

This study analyzed trace elements (Cu, Pb, Zn, Cr, Cd, As, and Hg) in 42 surface sediment samples collected from the Yellow River Estuary and Laizhou Bay to characterize their spatial distributions and pollution statuses. Determination of trace elements was carried out by ICP-MS for Cu, Pb, Zn, Cr, and Cd, and by AFS for As and Hg. The results showed that the average concentrations for Cu, Pb, Zn, Cr, Cd, As, and Hg were 13.21 mg kg-1, 10 .61 mg kg-1, 21 .03 mg kg-1, 24 .41 mg kg-1, 0.14 mg kg-1, 6.47 mg kg-1, and 14.15 mu g kg-1, respectively. All the trace elements were classified in the first-class sediment according to the Chinese national standard 'Marine Sediment Quality'. The higher concentrations and pollution levels were found in the eastern Yellow River estuary which due to inputs from the Yellow River, and northeastern Laizhou Bay which could be attributed to the impacts of human activities at Longkou Port. This study has important scientific value for further understanding the source-sink effects of pollutants and regional environmental effects of heavy metals.