Mercury Content in Tinned Molluscs (Mussel, Cockle, Variegated Scallop, and Razor Shell) Normally Consumed in Spain, 2005

Concentrations of mercury were determined for tinned molluscs (Mollusca, Bivalvia), i.e., mussels (Mytilus spp.), cockles (Cerastoderma edule), variegated scallops (Chlamys varia), and razor shells (Ensis spp.), consumed in Spain. A total of 220 samples were analyzed: 120 mussels, 40 cockles, 24 variegated scallops, and 36 razor shells. Samples were obtained weekly from markets in Santa Cruz de Tenerife (Canary Islands) over a period of 12 months. All observed concentrations of mercury were below the maximum permitted for human consumption (0.5 mg/kg) as defined by European Community Decision 93/351/CE. Mercury concentrations were 27.28 ± 12.43 μg/kg for mussels, 66.59 ± 23.53 μg/kg for cockles, 33.68 ± 15.76 μg/kg for variegated scallops, and 21.26 ± 12.24 μg/kg for razor shells. To evaluate the importance of mercury as a food contaminant, the percentage ingested daily, the weight of mercury in the diet, and the calculated percentage of this metal in the diet contributed by reference species were estimated.