Toxic metals speciation in river Tisa

Abstract

19 mines (''hot spots'') in the Tisa river basin (the Danube confluence area) present constantly a source of metal contamination as a result of mining operation or of a naturall occurrence. Recently, as a consequence of the damages in the mines, the presence of toxic metals became again actual. The presence of heavy metals in the river was analysed using fish as biomarkers. Analysed contents of metals in different tissues of fish (muscle and bones, skin, gills, brain, liver and kidneys) were compared to population variation in control units. We found out that fish from the river Tisa have more toxic metals (we analysed all important organs as means for indication of metal toxokinetic and toxodynamic), than controls )the same species of fish from fish pound). Enhanced contents of Cu, Fe, Mn, Zn and Hg as well as As were determined in target organs of examined fish. All the values are not over maximum available concentration (MAC) and if we consider rules and law, it can be summarised that analysed fish are appropriate for use. Clearer understanding of consequences of enhanced content of toxic metals is a challenge of eco-toxicology today as well as prediction of changes and effects, bearing in mind synergistic effects of metals and influence of other substances.