[Evaluation of mutagenic activity in water disinfected with chlorine].

City of Wrocław is supplied with water from Oława. The main contaminations of water are high concentration of organic compounds and bacteria count. Raw and drinking water show some mutagenic and carcinogenic properties in Ames tests. To improve the quality of drinking water now technology bored on infiltrated water composed of, coagulation, filtration and disinfection was tested. The goal of investigation and was to examine mutagenic and carcinogenic properties of raw and treated water. Potential carcinogenic activity of volatile disinfection-by-products was estimated by direct analysis of THMs, while for nonvolatile halogenated organic substances Ames test was used. Carcinogenic risk based on THMs concentration could be estimate as 10(-5) for chlorine and 10(-6) for chlorine dioxide. Ozonation and post chlorination did not lowered the risk. Positives results of Ames test obtained for raw water no 2 with Salmonella typhimurium TA100, and for chlorinated treated water with Salmonella typhimurium TA98. The treatment of water with chlorine transforms same compounds into carcinogenic chlorinated derivatives and does not eliminate its harmful properties. Our results suggest that not all methods of treatment remove harmful to the health components from the water. Consequently in the case of the presence of such compounds in surface water it is necessary to employ appropriate methods and procedures the used Ames test allows rapid determination of the presence of carcinogenic compound in water. In Poland determination of the presence of potential carcinogens in water destined for the supply of urban areas is not obligatory and standard analyses of chemical composition do not give such information. It seems that the mentioned test could be considered for the control of the quality of raw and treated water as an indispensable measure contributing to reducing the health hazard for the population.