COPPER, IRON, SELENIUM, ZINC AND MAGNESIUM CONCENTRATIONS IN OYSTERS (ostrea edulis) FROM THE CROATIAN ADRIATIC COAST

The aim of the study was to determine and compare the concentrations of essential elements (Cu, Fe, Se and Zn) and the macronutrient Mg in oysters (Ostrea edulis) from six different farming sites along the Croatian Adriatic coast. This is the first study to determine the accumulation of Cu, Fe, Mg and Se in oysters in Croatia. The concentrations of elements were determined in the ranges (mg kg-1, wet weight): Cu 8.84-76.6, Fe 22.4-69.3, Se 1.66-4.88, Zn 129-737, Mg 607-1226. There were no significant differences in Fe, Mg and Se concentrations between sites. Significantly higher Zn and Cu levels were measured in oysters from Pag compared to those collected at localities in Mali Ston Bay. The results indicate an environmental influence on element levels in oysters. The estimated daily intakes (EDIs) calculated in oysters show a low contribution (0.008-2.52%) to the recommended dietary allowance (RDA) for these five elements. According to risk assessment results, it can be concluded that it is unlikely that the intake of Fe, Mg and Se through oysters would involve any risk for the average consumer. However, the high contribution of the EDI values to the provisional maximum tolerable daily intake (PMTDIs) obtained for Cu and especially for Zn suggests that oysters may pose a health risk to consumers.