Occurrence and distribution of heavy metals in surface sediments of the Changhua River Estuary and adjacent shelf (Hainan Island)

Heavy metal (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) concentrations in surface sediments from the Changhua River Estuary and adjacent shelf, western Hainan Island, were conducted to evaluate the level of contamination. Numerical Sediment Quality Guidelines (TEL and PEL) were applied to assess adverse biological effects of these metals, suggesting that occasional biological effect may occur due to As, Cr, Cu, Ni, and Pb. Enrichment factors shown that the significant As and Pb contaminations in the study area. Multivariate analysis indicated that the sources of Cd, Cr, Cu, Hg, Ni and Zn resulted primarily from natural weathering processes, whereas As and Pb were mainly attributed to anthropogenic sources. The results of this study would provide a useful aid for sustainable marine management in the region.