Genotoxic response of Austrian groundwater samples treated under standardized UV (254 nm) - disinfection conditions in a combination of three different bioassays

Ground water samples from different geographic areas in Austria, with diffe rent amounts of natural and anthropogenic organic compounds were treated wi th a standardized low pressure UV (254nm)-irradiation laboratory flow-throu gh system (UV fluence: 800 J/m(2)). The genotoxic activities of the water s amples before and after the UV disinfection were investigated using a combi nation of three different bioassays which complement each other with regard to their sensitivity detecting different genotoxins. The test battery comp rises the Salmonella/microsome assay (Ames test with TA98, TA 100 and TA 10 2, with and without S9 mix) and two micronucleus tests with the plant Trade scantia (clone #4430) and with primary rat hepatocytes. Overall, the tested Austrian groundwater samples used for human consumption caused only weak g enotoxic activities compared to drinking water samples reported from other countries under similar experimental conditions. With the exception of one weak positive result in the Ames test (only in strain TA98 without S9 mix) with an induction factor of 1.9) all samples after UV disinfection were dev oid of additional mutagenic and clastogenic activities compared to the samp les before UV disinfection. (C) 2001 Elsevier Science Ltd. All rights reser ved.