Heavy metal concentration and its evaluation in the organisms from Meizhou Bay

The present paper reports Zn, Cu, Pb, Cd, Ni, Fe, Mn and Co contents in the tissues of oyster, solen, red-tail prawn, sea eel and kelp, taken from Meizhou Bay (and analysed by flame atomic absorption spectrophotometry after wet digestion) in June 1992, and also the concentration factors estimated from the mean metal concentrations in the organisms and water there. Heavy metal concentrations in every species of the organisms followed the pattern: Fe, Mn, Cu, Zn>Pb, Cd, Ni, Co and in various organisms showed considerable variation. In general, levels of most of these metals were in the order: soft tissues of the bivalves > the kelp > muscles of the red-tail prawn, the sea eel. The greatest concentration of most metals was found in the gill or viscera of the sea eel, whereas the muscle tissues, in general, contained only low concentrations of them. The Cu, Zn concentration factors of the oyster were higher by 1 - 2 orders of magnitude than that of the other organisms. The observed heavy metal levels were close to those reported from various waters throughout the world, far lower than "Evaluation Standard for Polluting Substances in Marine Organisms" and "Medical Standard for Human Consumption". This study showed that marine organisms from Meizhou Bay are hardly polluted by heavy metals.