Distribution, source, and contamination assessment of heavy metals in surface sediments of the Old Yellow River Estuary in China

To assess the sources and pollution status of heavy metals, surface sediments from the Old Yellow River estuary were systematically sampled and analyzed to determine the concentrations of seven heavy metals. The Pearson's correlation coefficient, enrichment factor, geoaccumulation index, and principal component analysis were used to distinguish the sources and assess the pollution risk of heavy metals. The results showed that the distributions of Al, Fe, Cu, Pb, Zn, Cr, and As were similar and mainly dominated by fine-grained sediments, whereas the distributions of Cd and Hg were irregular. Al was strongly correlated with Fe, Cu, Pb, Zn, As, and Mz, and positively correlated with Cr. Except for Cr, Cd, and Hg, all the other elements were positively correlated with Mz. Multiple indicators indicated that Cu, Pb, Zn, Cr, and As were mainly derived from natural sources, whereas Hg and Cd were derived from anthropogenic sources.

Automated summary

This study assessed the sources and pollution risk of heavy metals in the Old Yellow River estuary by systematically sampling and analyzing surface sediments. Multiple indicators were used to distinguish the sources and assess the pollution risk. The results showed that some heavy metals were derived from natural sources, while mercury and cadmium were derived from anthropogenic sources.