Genotoxic effects of wastewater from an oncological ward.

Aim of this study was the evaluation of the genotoxic activities of hospital wastewaters. Samples from an oncological ward of the general hospital of Vienna, Austria, were tested in the Salmonella/microsome assay in strains TA98, TA100 and TA1535 with or without metabolic activation, and in the single-cell gel electrophoresis (SCGE) assay with primary rat hepatocytes. In the bacterial tests, consistently negative results were obtained while in the experiments with liver cells a significant and dose-dependent induction of DNA damage (up to two-fold over the background) was found. Membrane filtration resulted in a substantial (62-77%) reduction of these effects, while additional treatments (activated carbon filtration and UV-irradiation) did not lead to a further decrease of the genotoxic activity of the samples. SCGE experiments with cisplatin, carboplatin and 5-fluorouracil, which were detected in the water samples, showed that these cytostatics cause a significant induction of DNA damage only at concentrations that are substantially higher than those in the native waters. These findings indicate that other chemicals, possibly quaternary ammonium compounds, account for the effects of the hospital wastewaters.