Potentially Toxic Metals in Sediments from Liao River Estuary Wetland: Concentration, Source, and Risk Assessment

In this study, a total of 26 surface sediments samples are collected from the Liao River estuary wetland, China. The concentration, potential ecological risk, and source apportionment of potentially toxic metals including Sr, Zn, Cr, Ni, Pb, Cu, and As in different seasons are analyzed. The average concentrations of potentially toxic metals are below the first class of Chinese marine sediment quality standard. There is no significant difference in the concentrations of potentially toxic metals in the sediments collected in June and November. The concentrations of potentially toxic metals in the periphery of the nature reserve are higher than those in the core area of the nature reserve. The average enrichment factors of As, Pb, Cu, Ni, Zn, and Cr are about 1, classified as minimal enrichment. The average enrichment factor of Sr is >2, which corresponds to moderate enrichment. The individual (E-r) and total potential ecological risks (RI) of potentially toxic metals are low. The positive matrix factorization model suggested that the potentially toxic metals in surface sediments in June are dominantly from atmospheric deposition, industrial discharges, natural sources, and traffic emission. However, the traffic emission source is replaced by agricultural production and metal smelting activities in November.