Sources and ecological risk assessment of the seawater potentially toxic elements in Yangtze River Estuary during 2009-2018

The purpose of this paper is to understand the sources of potentially toxic elements (PTE) and provide some suggestions to control PTE pollution. For this purpose, data from 30 monitoring stations for 2009-2018 were used to assess the PTE concentrations of Hg, Cu, Pb, Cd, Zn, and As in the Yangtze River Estuary. The PTE concentrations varied significantly (P < 0.05) by one-way ANOVA in the ranges of 0.002-0.224 (Hg, 0.043 0.032), 0-9.700 (Cu, 1.600 +/- 1.000), 0-3.900 (Pb, 1.000 +/- 0.700), 0.002-0.370 (Cd, 0.050 +/- 1.000), 0.100-85.000 (Zn, 14.000 +/- 13.000), and 0.998-3.290 mu g/L (As, 1.857 +/- 0.455). Generally, the PTE concentrations decreased from year to year and were consistently satisfied the grade-one seawater quality standard after 2014. The concentrations of Cu, Cd, Zn, and As decreased as far from inshore, while increased closer to land in the estuary. Concentrations of Pb and Hg showed differences because of local industrial and aquacultural activities. This study identified three clusters and two PTE sources and provided some constructive suggestions for pollution control in PTE.

Automated summary

This study analyzed the sources and concentrations of PTE in the Yangtze River Estuary using data from 30 monitoring stations from 2009 to 2018. The results showed that PTE concentrations decreased over the years and generally met seawater quality standards after 2014. Different behavior patterns were observed for different PTE, with some decreasing further from shore and others affected by local industrial and aquacultural activities. Three clusters and two PTE sources were identified, along with suggestions for pollution control.