Concentration distribution and assessment of heavy metals in surface sediments in the Zhoushan Islands coastal sea, East China Sea

In an effort to assess the potential contamination and determine the environmental risks associated with heavy metals, 51 surface sediment samples (0-4 cm) were collected in the Zhoushan Islands coastal sea of the East China Sea (ECS). The heavy metal concentrations, grain size and total organic carbon (TOC) contents of these surface sediments were comprehensively analyzed. The results showed that the order of the average concentrations of heavy metals is Zn > Cr > Cu > Pb > As > Cd > Hg. Zn, Cr, Cd and Hg exhibit similar distribution and which derived from a common source, however, Cu, Pb and As present different distribution. The metal enrichment factor (EF) and geoaccumulation index (I-geo) values both suggest that Cu and Cd likely pose environmental risks. The results of this study could provide scientific data to authorities in charge of sustainable marine management.