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(T/EH083) Potential genotoxic effects of surface drinking water treated with chlorine or alternative disinfectants. Guzzella, L.1, Monarca, S.1, Ferretti, D.2, 1 2 ABSTRACT- A battery of in vitro short-term genotoxicity tests revealing different genetic end-points will be set up in order to apply it for the study of surface drinking water treated with different disinfectants. First this integrated approach will be applied for studying surface waters disinfected with sodium ipochlorite, because this compound is known to produce many genotoxic disinfection by-products both volatile (e.g. THM) and non-volatile. For assessing chlorine dioxide activity a full-scale drinking water treatment plant using surface water and chlorine dioxide will be chosen, due to the impossibility to generate this compound in laboratory. This disinfectant has almost completely replaced chlorine for the disinfection of drinking water in Italy and in Europe. At this plant surface water samples were treated with sodium ipochlorite in acquarium where fishes and mussels will be exposed for some days. The surface water both before and after chlorination was also concentrated by adsorption on C18 silica cartridges and the concentrates containing non-volatile organics were divided in different portions for the in vitro tests. The following in vitro tests were performed on the water concentrates dissolved in DMSO: Ames test with TA98 and TA100 strains +/-S9; SOS Chromo test with Escherichia coli, Mutatox assay with Vibrio fischeri. The concentrates showing mutagenicity were characterized by chemical analyses using gas-chromatography/mass specttrometry. Following this integrated in vitro approach we were able to study the water samples in their real composition using tests that reveal different genetic end-points. The data obtained were related to the real human exposure and give a better genotoxicological profiles of the new compounds produced by the disinfection of drinking water. The comparison of the by-products formation potential of ipochlorite, chlorine dioxide and peracetic acid used in disinfection of surface water gave information particularly useful for health authorities and water works managers for the production of high quality drinking water Key words: mutagenicity, SOS Cromo test, Mutatox, Ames test |
