Heavy metals in marine food web from Laizhou Bay, China: Levels, trophic magnification, and health risk assessment

Abstract

Heavy metals in ocean may accumulate in seafood through food web and pose risks to human health. This study investigated the occurrence, trophic magnification, and health risks of 7 heavy metals in 20 marine organisms (n = 222) in Laizhou Bay (LZB), China. Results showed that Zn was the most abundant metal, followed by Cu, As, Cd, Cr, Ni and Pb. The total concentrations of 7 heavy metals in the organisms ranked in the order of crab ˃ shellfish ˃ algae ˃ fish ˃ starfish. Interspecific differences were found in the concentrations of Cr, Ni, Cu and Cd in marine organisms from LZB. Crab and shellfish showed much higher enrichment ability of heavy metals than that of algae, starfish and fish. Cd is the most biological accumulated element with the mean biota-sediment accumulation factor (BSAF) of 12.9. Stable isotope analysis showed a significant difference of δ15N among these five species (p < 0.01), and a food web was constructed accordingly. A biodilution pattern was found for Pb, As and Ni and no trophic interference in metal uptake was observed for Zn, Cu, Ni and Cr in the food web of LZB. The estimated daily intake (EDI) and target hazard quotients (THQs) of As and Cd indicated an adverse health effect on consumption of the seafood. The mean lifetime cancer risks (LCRs) for Cd and As suggested a potential carcinogenic effect on consumption of these seafood. This study provides a basis for health risk assessment of heavy metals in marine foods.