RISK ASSESSMENT OF TOXIC ELEMENTS (Pb, Cd, Hg, As) IN WATER, SEDIMENT AND IN THINLIP GREY MULLET (BOJANA RIVER)

The Bojana River is outflow of the Skadar Lake. River is shared by Albania and Montenegro, it forms part of their border before flowing into Adriatic Sea. During most of the year the water quality of the Bojana River is acceptable, but pollution increases the most frequently in summer period.For this study, research of toxic elements (Pb, Cd, Hg, As) in the water and sediment of the Bojana River, as well as in the muscle tissue and digestive tract tissue of thinlip grey mullet (Chelon ramada) was done at the end of the summer season. This research of toxic elements in muscle tissue and digestive tract tissue of thinlip gray mullet is done for the first time for this species, as well as bioconcentration factor (BCF), biota sediment accumulation factor (BSAF) and Spearman correlation between the matrices. The grade of metals concentrations decreased in the subsequent order: As Pb Cd=Hg in water and As Pb Cd Hg in sediment. The order of decreasing concentration for metals in muscle tissue is as follows: Hg Pb=Cd=As and in digestive tract tissue of thinlip grey mullet: Pb Hg Cd=As. The highest values of BCF in muscle tissue of fish have been established for Hg and Cd and in digestive tract for Pb and Hg. The values of biota sediment accumulation factor (BSAF) decreased in the following order: Hg Cd Pb=As for muscle tissue and Hg Pb Cd As. for digestive tract tissue.