Heavy Metals in the Sediment of the Islands of Lastovo and Mljet and the City of Dubrovnik

Abstract

The content of heavy metals (Fe, Mn, Zn, Cu, Cr, Hg, As, Pb and Cd) in the sediment of the marine aquatoriumof the islands of Lastovo and Mljet, and the city of Dubrovnik was examined in order to determine their impact on the environment. Divers collected the samples in a layer of 10 cm and 5 cm at the planned locations. The sample preparation was performed in the laboratory in an autoclave with acids in teflon vessels at elevated temperature. Determination of the concentration of elements was made on an atomic absorption spectrophotometer (AAS), by the method of flame, cold and hot vapors, and nickel vessels. The marine aquatorium of the islands of Lastovo and Mljet are not polluted with ecotoxic elements, while an increased concentration of mercury, arsenic and lead has been found in the marine aquatoriumof the city of Dubrovnik at several locations.