Source apportionment and ecological risks of trace metals in multiple media in a typical Chinese industrialized bay...

The concentrations and risks of trace metals (TMs) in different media of aquatic systems are gradually increasing, driven by increasingly frequent anthropogenic activities. This research aimed to examine the distribution and bioaccumulation patterns of TMs in various environmental media via the analysis of samples from a typical petrochemical industrial bay in southern China. In addition, the ecological risks and anthropogenic sources of these elements were assessed. The results indicated that the levels of Zn and Hg were highest and lowest, respectively, in surface seawater, sediment, and seafood, with other TMs varying in content between those of these two trace metals. The integrated pollution index (IPI) values for TMs in seawater ranged from 1.13 to 3.16, remaining at a minimal contamination level. After multiple pollution assessment methods, were comprehensively applied, Cd and Hg were highlighted as key contributors to significant pollutant buildup and elevated ecological risks in sediments. Based on the combined use of geographic information system (GIS), self-organizing map (SOM), and positive matrix factorization (PMF) methods, the sources and contributions of TMs were analysed. The results revealed that fossil fuel combustion (24.3 %), natural geological processes (48.0 %), and aquaculture practices (27.7 %) were the primary sources of TM accumulation in sediments. This study provides important data for reducing TM pollution in typical petrochemical industry bays, enhancing ecological safety, and assessing the risks of potentially toxic elements in seafood to human health.