Flow cytometric measurement of micronuclei induced in a permanent fish cell line as a possible screening test for the genotoxicity of industrial waste waters

An in vitro micronucleus assay using the permanent fish cell line RTG-2 (ra inbow trout gonads) was developed to test industrial waste waters for their genotoxic potential, Comparison of flow cytometric measurement and microsc opic scoring of micronucleus frequency with the reference chemicals 1,4-but ane sultone (0.2-1 mM), ethylmethane sulphonate (2-10 mM), potassium dichro mate (20-100 mu M) and benzo[a]pyrene (5-25 mu M) showed similar dose-effec t relationships. Thirty-eight industrial waste waters from 11 different bra nches of industry obtained from the Bavarian state office for water researc h were tested using the flow cytometric method (18 from metal processing, 1 0 from combined waste water, two from synthetic fibre production, one sampl e each from settlement wastes, non-iron metal manufacturing, leather produc tion, sulphuric acid production, ore processing, graphite film production, cellulose production and flue gas washing). Fourteen of them showed a signi ficant increase in micronucleus frequency.