Genetic risk assessment of acid waste water containing heavy metals.

The mutagenic/cancerogenic potential of acid-mine water from the Slovak mining area Rudnany containing a high load of toxic metals was evaluated after its application to three model test organisms (bacteria Salmonella typhimurium, yeast Saccharomyces cerevisiae and plant Vicia sativa L.). The results obtained from the modified preincubation Ames assay proved that 1000-fold diluted waste water exhibited mutagenic effect in three (TA97, TA98, TA102) of four bacterial strains. In the test on yeast the toxicity and genotoxicity increased as a function of the concentration. At the highest concentration used (0.06%) the frequency of revertants increased 6 times and convertants increased 4.5 times above the control level. In the simultaneous phytotoxicity and clastogenicity assay, concentration dependent toxicity and statistically significant clastogenicity was proved. We can conclude that heavy metals might be responsible for the genotoxic/cancerogenic potential of the test water. However, we do not entirely exclude the possibility that its genotoxicity might be promoted by its high acidity.