Cytogenetic analysis of human peripheral blood lymphocytes in culture exposed in vitro to styrene and styrene oxide.

Styrene and styrene oxide mutagenicity was tested in cultured human lymphocytes treated in vitro with various concentrations of test agents. Styrene alone was found mutagenic at the highest concentration used (5 X 10(-4) mol. l-1, combined with the alkylating agent THIO-TEPA it did not affect the chromosome aberration yield. Exposure to styrene oxide gave a positive result showing a clear-cut dose-effect relationship within the concentration range 5 X 10(-6) to 1 X 10(-3) mol. l-1. In combination with THIO-TEPA its effect on chromosome aberration yields was additive. Styrene oxide proved also to be a very potent inducer of sister chromatid exchanges (SCE) within the concentration range 5 X 10(-6) to 1 X 10(-3) mol. l-1 tested. Combined with THIO-TEPA it exhibited a distinct additive effect in the production of SCEs.