Biologically available trace metals in Mytilus edulis from the coast of northeast England

The concentrations of Fe, Mn, Zn, Cr, Cu, Pb, Ni, Cd, and Ag were determine d in soft tissue and shell material of mussel Mytilus edulis collected in t he winter season from five coastal sites in the northeast of England. The t race metal levels observed were significantly high, particularly at locatio ns affected by past coal mining activities (Blackhall) and present industri al sources (Middleton). The mussels from the chosen control site (Holy Isla nd), a shellfish-designated area, were particularly enriched in Cu and Ag. The metal pollution index for the Bran Sands site, a heavily industrialised area on the Tees Estuary, was relatively low. At four sites out of five, t he levels of Fe and Cu were negatively correlated with mussel size. No sign ificant correlation with size was found for the other metals. With few exce ptions, the elements Fe, Zn, and Mn accumulated preferentially in the soft tissue, whereas Pb, Cd, Ct, Ag, and Ni were more abundant in the hard part of the mussels. The Ag values in shell material were remarkably similar (ab out 6 mg kg(-1) - 7 mg kg(-1), dry wt) at all sites studied. In general, th e data show that the mussels from the coastline studied accumulate metal co ncentrations comparable to or higher than the most contaminated sites repor ted in the literature. (C)1999 Elsevier Science Ltd.