Distribution and pollution risk assessment of heavy metals in the surface sediment of the intertidal zones of the Yellow River Estuary, China

Eleven heavy metals (V, Cr, Mn, Co, Fe, Ni, Cu, Zn, As, Cd, and Pb) in surface sediment in the intertidal zones of the Yellow River Estuary, China were analyzed by inductively coupled plasma-mass spectrometry in summer and autumn 2019. Results indicated that the 11 heavy metals had the same sources. Sediment particle size and total organic matter were the main factors influencing the distribution of heavy metals. Most sites in the intertidal zones of the study area were not contaminated with V, Cr, Fe, Co, Zn, Pb, Cu, As, Mn and Ni, while Cd was the priority pollutant. Heavy metal pollution risk in autumn was higher than that in summer, which may be due to hydrodynamic effects. The present study showed that the heavy metal concentrations in the study area had a temporal decreasing trend compared to previous studies, which may be due to the reduction in human activities.

Automated summary

This study analyzed the concentrations of 11 heavy metals in surface sediments in the intertidal zones of the Yellow River Estuary, China. The results showed that these heavy metals had the same sources. Sediment particle size and total organic matter were the main factors influencing their distribution. Most sites in the study area were not contaminated with these heavy metals, except for cadmium. The risk of heavy metal pollution was higher in autumn than in summer. The findings also suggested a temporal decreasing trend in heavy metal concentrations, possibly due to reduced human activities.