Occurance of heavy metals in sediments and biota in Northern Adriatic Sea

Due to the low depth and the modest water exchange, Adriatic Sea is considered a fragile area. In particular, the Northern area receives fresh water input from a series of sources; the most important one is the Po River which drains intensely cultivated and industrialized hinterland areas and releases into the sea great amounts of dissolved and particulate materials, including anthropogenic contaminants. The aim of this study was to monitor heavy metals concentrations, in biotic and abiotic samples. Heavy metals, especially mercury, are often present in industrial and municipal effluents and are ubiquitary pollutants frequently detected in the environment that can cause long-term effects on marine ecosystems. In particular, samples of sediments, fishes and filter-feeding organisms, collected in the North-Est area of Adriatic Sea were analyzed. The samples were homogenized and digested with nitric acid and hydrogen peroxide by using microwave-oven technique. The analyses were performed by graphite furnace absorption spectrometry (Cd and As), atomic emission spectrometry (ICP-AES) (Ba, Cr, Fe, Mn, Ni, Pb, Cu and Zn) and cold vapour atomic absorption spectrometry after amalgamation traps on gold for the preconcentration of mercury in order to lower the detection limit of the analyte.