Heavy metal pollution in the Yongjiang Estuary, China and their relations to environmental factors

Abstract

Abstract This study aimed to investigate the relationship between 8 heavy metals (Pb, Cd, Mn, Ni, Cr, Fe, Cu and As) and 11 environmental parameters at five sites during the tide rising and ebbing durations of surface water over four seasons in the Yongjiang Estuary, China. The results found that the change concentrations of heavy metals and environmental factors were high, which had obvious spatial distribution and seasonal dynamic characteristics. In the aspect of spatial distribution, the concentrations of heavy metals and the physical and chemical indexes were higher at the points near the industrial area. In the aspect of seasonal dynamics, the concentrations of Pb, total phosphorus and ammonia nitrogen were the highest in winter. In the aspect of tidal change, the change rules of different indicators were different, among which, the concentrations of Cd, Ni and total nitrogen in the rising tide and ebb tide were quite different. The concentration of dissolved organic carbon, total nitrogen, pH, salinity, ammonia nitrogen and chlorophyll a were positively correlated with target heavy metals. This study explored the relationship between the concentrations of heavy metals and environmental parameters, which is beneficial to future heavy metals research in estuaries.