Historical records of trace metals in core sediments from the Lianyungang coastal sea, Jiangsu, China.

We analyzed element concentrations in cores from the Lianyungang coastal sea to determine depositional trends and geochemical sources of metals. Enrichment factors (EFs) and pollution load index (PLI) were used to assess the enrichment and pollution of metals. Profiles of vertical distributions of the elements reflected different depositional environments in 3 cores. Cores A and C deposited sediments with rich terrestrial elements by rivers, corresponding to mixed-up patterns in the sediment. Meanwhile, core B was mainly deposited in a less undisturbed depositional environment. Correlations and principal component analysis indicated that sediments were influenced by natural and anthropogenic impacts. According to the EFs, most metals showed no significant enrichment and pollution in the core sediments. Lastly, PLI values (<1) of sediments indicated that the Lianyungang coastal sea was a lowly polluted area despite PLI value of metals in average sediment was lower than that in surface sediment.