Heavy metals monitoring in the southernmost mussel farm of the world (Beagle Channel, Argentina)

Water quality surrounding the mussel farm of Mytilus edulis chilensis at Brown Bay (Beagle Channel) was evaluated. The levels of five heavy metals in sediment and in gill and digestive gland of mussels were examined to consider potential risks to human health. Cd showed the highest enrichment factor in relation to its level in Earth crust (3.85-21.58), which could be related to an upwelling phenomenon. A seasonal trend was found regarding metal bioaccumulation, being higher in winter than in summer. The bioaccumulation pattern in gill was Zn > Fe > Cu > Cd, meanwhile in digestive gland was Fe > Zn > Cu > Cd. Despite Pb was measured in sediment (15.59-23.91 mu g/g dw), it was not available for being incorporated by mussels. In all cases it was below the detection limit (2.37 mu g/g dw). With regard to human consumption of mussels from Brown Bay, none of the elements analyzed should cause concern for consumers. Values measured in tissue mussels were below the limit of 10 mu g/g dw for Cd and Pb established by SENASA for molluscs. Considering that studied mussels are for human consumption and the relatively high levels of metals in sediment may vary their availability if physical parameters changes, periodical monitoring must be carried out to avoid human risks and to produce food in a responsible manner that complies with the food safety standards. (C) 2010 Elsevier Inc. All rights reserved.