ACCUMULATION OF HEAVY METALS IN Arca granosa

This paper explores the accumulations ana distributions of Cd, Pb and Cu in clam Area granosa through determining their contents in Dlood and soft parts. The results show an order of concentration factors for these metals therein as:Cd > Cu > Pb; the values of concentration factors and the patterns of distribution are similar for Cu and Pb but different from Cd. Concentration factors in blood can reflect the enrichement abilities of soft parts. Exposure experiments have indicated that the Pb level in blood is controlled by Pb concentrations in surrouding seawater, changing with time, that the Pb cocentration causing poisoning in the seawater is 1-100 μg/l, and that the Pb content in blood and soft parts of Area granosa increases with that of Pb increasing in seawater. There exist relationships of double logatithmic concentrations for Pb among the three mediums.