DIFFERENT GENOTOXICOLOGICAL RESPONSES OF MINE WATERS CONTAINING HEAVY METALS

ABSTRACT Two samples of the acid-mine water (AMW) containing heavy metals were collected in the year 1995 and 1998 in the former mining area of Banská Štiavnica-Šobov (Slovakia), and assayed for their genotoxic potential by the Ames assay and the DNA-topology assay. The content of toxic metal elements, determined by atomic absorption spectroscopy, was decreased in the sample of AMW collected in the year 1998 in comparison with that determined in the year 1995. The sample collected in 1995 was genotoxic after its application on bacterial strain Salmonella typhimurium TA97 (without metabolic activation), and TA102 (with metabolic activation). The sample collected in 1998 did not increase the frequency of his+ revertants in the same bacterial strains. Moreover, the DNA-topology assay (which facilitates electrophoretic monitoring and densitometric quantification of changes in a plasmid DNA structure) revealed the presence of 81.3% of the slowly migrating plasmid DNA, and 18.2% of the relaxed plasmid DNA after incubation of the plasmid DNA with the sample collected in 1998, and respectively after the joint incubation of this sample with glutathione and hydrogen peroxide.