Induction of micronuclei in human lymphocytes by organic solvents in vitro.

Our work is focused on identifying micronuclei (MN) induced in whole blood lymphocyte cultures after treatment with the organic solvents toluene, benzene, and acetone. We used the micronucleus test as a cytogenetic biomarker for genotoxicity and treated whole blood cultures with different concentrations of these solvents (0.1 to 5 mM) and mixtures of them (toluene plus acetone, toluene plus benzene). Our results did not show a significant increase in the number of micronuclei in binucleated lymphocytes after 48 hr of in vitro treatment. The addition of an external metabolic factor (10% S9 mix for 2 hr) in blood cultures treated with the organic solvents or their mixtures did not cause induction of MN. These results indicate the lack of genotoxic activity of toluene, benzene, and acetone in vitro.