Heavy metals and arsenic in sediments, mussels and marine water from Murano (Venice, Italy)

This paper describes a study of the trace element distribution in sediments, marine water and mussel Mytilus galloprovincialis of the Venetian Lagoon around the Island of Murano, an island with a long tradition of glassmaking. Trace elements analysed include Fe, Mn, Zn, Cu, Cr, Pb, Ni, Ag and As. Sediments are contaminated with Zn, Cu, Ag, As and Pb, with levels in the <2 m fraction that are likely to cause adverse biological effects to marine organisms. The pelite (<63 mum) is the main carrier of heavy metals at most sites. However, the fine-grained and coarse sand on the southern coast of Murano accounts for a significant proportion of Fe, Mn, Zn, Cr, Ag, Ni and Pb. Most trace element concentrations found in soft tissue of mussels appear to be within recommended Italian and international guidelines for shellfish for human consumption, the only exception being relatively high As levels. The bioaccumulation of Ag and Cr is more pronounced in the shell of these organisms. In the marine water of the lagoon, trace elements are more enriched than in other areas of the Mediterranean, with particular reference to the dissolved labile species of Zn, Mn, As, Cu, Ni and Cr.