In this study, we investigated the concentrations of ten trace elements (Cu, Zn, Mn, Se, Ni, Cd, Cr, Pb, Hg, and As) and their trophodynamics in a benthic food chain of Deer Island, Northern Yellow Sea. The concentrations of Cu, Zn, Mn, Se, Ni, Cd, Cr, Pb, Hg, and As in the food chain ranged from 3.2 to 23.2, from 71 to 227, from 7.4 to 45.6, from 0.44 to 5.80, from 0.73 to 7.60, from 0.14 to 1.65, from 0.68 to 6.70, from 0.08 to 1.86, from 0.08 to 1.18, and from 0.24 to 3.92 mg kg⁻¹ dry weight, respectively. Among these trace elements, the linear regression between the log-transformed concentrations of Hg and Cd and δ¹⁵N values showed statistically significant increase (p<0.05) with the slopes of 0.134 and 0.144, indicating biomagnification of Hg and Cd occurred in the benthic food chain of Deer Island. While the linear regression for other eight trace elements (Cu, Zn, Mn, Se, Ni, Cr, Pb and As) were characterised by extensive scatter with non-significant correlation coefficients (R ²=0.002–0.235) and slopes (p=0.079–0.875), indicating there were not biomagnified or biodiluted of these trace elements.

The Manila clam Ruditapes philippinarum is one of the most important commercial bivalve species consumed in China. Evaluated metal burden in bivalve molluscs can pose potential risks to public health as a result of their frequent consumption. In this study, concentrations of 10 trace elements (Cu, Zn, Mn, Se, Ni, Cd, Cr, Pb, Hg and As) were determined in samples of the bivalve Ruditapes philippinarum, collected from nine mariculture zones along the coast of China between November and December in 2010, in order to evaluate the status of elemental metal pollution in these areas. Also, a public health risk assessment was untaken to assess the potential risks associated with the consumption of clams. The ranges of concentrations found for Cu, Zn, Mn, Se, Ni, Cd, Cr, Pb, Hg and As in R. philippinarum were 12.1–38.0, 49.5–168.3, 42.0–68.0, 4.19–8.71, 4.76–14.32, 0.41–1.11, 0.94–4.74, 0.32–2.59, 0.03–0.23 and 0.46–11.95 mg·kg⁻¹ dry weight, respectively. Clear spatial variations were found for Cu, Zn, Cr, Pb, Hg and As, whereas Mn, Se, Ni, and Cd did not show significant spatial variation. Hotspots of trace element contamination in R. philippinarum can be found along the coast of China, from the north to the south, especially in the Bohai and Yellow Seas. Based on a 58.1 kg individual consuming 29 g of bivalve molluscs per day, the values of the estimated daily intake (EDI) of trace elements analyzed were significantly lower than the values of the accepted daily intake (ADI) established by Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JFAO/WHO) and the guidelines of the reference does (RfD) established by the United States Environmental Protection Agency (USEPA). Additionally, the risk of trace elements to humans through R. philippinarum consumption was also assessed. The calculated hazard quotients (HQ) of all trace elements were less than 1. Consequently, there was no obvious public risk from the intake of these trace elements through R. philippinarum consumption.