Sensitivity of lymphocytes from vulcanizers to the in vitro induction of sister chromatid exchanges

Spontaneous frequencies of sister chromatid exchanges (SCEs) and SCEs induced in vitro by chemicals with different mechanisms of action such as mitomycin C, 4-nitroquinoline oxide, and 3-aminobenzamide were examined in phytohemagglutinin-stimulated peripheral blood lymphocytes from a group of workers in a rubber plant and a control group, both of which had been analyzed for levels of spontaneous SCEs 2 years earlier. An interindividual variability in the induction of SCEs was found after in vitro treatments with the different mutagens, which did not correlate with occupational exposure. This variability in the sensitivity to the induction of SCEs might be correlated to genetic differences among individuals, which have to be taken into account in environmental monitoring programs.