Analysis of eight known or suspected aneugens by the in vitro human lymphocyte micronucleus test

In the light of the CEC aneuploidy programme eight known or suspected aneugens were evaluated with the human lymphocyte 'in vitro' micronucleus test using the cytochalasin-B technique. Only colchicine, chloral hydrate and hydroquinone induced dose-dependent increases in micronucleus frequencies. The other five chemicals (cadmium chloride, econazole, pyrimethamine, thiabendazole and thimerosal) were all negative, both with and without S9, and treated in G1 or G2 phase. These data are in good agreement with results from different 'in vivo' studies. However, discrepancies were found between the results from this study of human lymphocytes and those of other cultured cell types where econazole, cadmium chloride, pyrimethamine and thiabendazole induce a significant increase of micronuclei.