Characterization, source identification, risk assessment of potentially toxic elements (PTEs) in the surface water and sediment of the Beibu Gulf, China

The concentrations, distribution, and risk of seven potentially toxic elements (PTEs), including As, Cd, Cr, Cu, Hg, Pb, and Zn, in seawater and sediment from the eastern Beibu Gulf of China were studied using national standard methods. Results showed that the concentrations of PTEs in seawater exhibited significant spatial and seasonal variations, resulting in tolerable non-carcinogenic and carcinogenic health risks for both adults and children. The sediment concentrations of PTEs were generally lower than historical values, indicating an acceptable pollution level and ecological risk, except for Hg. Granularity was found to be an important factor in regulating the distribution. Furthermore, principal component analysis (PCA) and positive matrix factorization (PMF) model simulation revealed that the sources of PTEs in sediment were primarily of natural origin, with the exception of Hg, which was predominantly of anthropogenic origin. The parent rock of As was different from that of other PTEs. •The distribution of PTEs (As, Cd, Cr, Cu, Hg, Pb, and Zn) in the seawater of Beibu Gulf varied seasonally and spatially.•The health risks posed by dermal contact with PTEs in seawater for both adults and children were acceptable.•Hg from the human activities was the major contributor to the sediment pollution and ecological risk.•Natural origins were the main source of all the selected PTEs, while the mother rock of As may be unique.