Integrated assessment of major and trace elements in surface and core sediments from an urban lagoon, China: Potential ecological risks and influencing factors.

Marine sediments serve as a sink for contaminants of anthropogenic origin. Here, 25 major and trace elements were determined in surface and core sediments from an urban lagoon (Yundang Lagoon), China. The median concentrations of Pb, Cd, Cu, and Zn in both surface and core sediments exceeded global and crustal averages. Principal component analysis for the elements and ecological impact of the heavy metals indicated spatial heterogeneity in core sediments from different lagoon areas; however, no such pattern was observed in surface sediments. Geodetector analysis indicated spatial locations of lakes, pH, N%, C%, and S% as the major factors influencing the heterogeneity of potential ecological risk index, a cumulative measure of the ecological impact of heavy metal. The interaction detector indicated nonlinear and bivariate enhancement between different physicochemical parameters. Besides, a depth profile of the elements in different samples was also elucidated.