Neutron Activation Analysis for Studies of Elemental Variability in the Wild and Farmed Molluscs

The neutron activation analysis was applied for investigation of elements temporal and spatial distribution among edible mussels. It allowed finding the levels of 29 macro and microelements in soft tissues and 24 in shells of such molluscs. For comparison, samples of wild and farmed mussels were collected from the sites with different anthropogenic pressure in the coastal zones of South Africa, Namibia, Mozambique, and Crimea. In general, the mussels from harbor zones contain higher levels of such elements of terrigenous origin such as Sc, V, Cr, Mn, Co, Ni, Sb, Cs, Th, U, while Co, Ni, Zn, As, Se, Br, I, Sb could have anthropogenic origin. According to our studies, the main factors which affect spatial variability of elements in the soft tissues and shells of mussels depend on the presence of resuspended bottom sediments, concentration, and content of phytoplankton, lithogenic composition of the coastal rocks, freshening of coastal waters, storm activities and hydrological parameters of environment waters and anthropogenic influence (wastewater discharges, marine transport, and harbor loadings).