Influence of some detoxification enzyme polymorphisms on cytogenetic biomarkers between individuals exposed to very low doses of 1,3-butadiene.

Objective: To evaluate the variation of some biomarkers related to the level of enzymatic activity dependent on the different polymorphisms.

Methods: We studied 27 butadiene-exposed workers and 37 controls using different biomarkers of the genotoxic effect. The genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism-polymerase chain reaction techniques; the subjects were assigned to a specific group based on the microsomal epoxide hydrolase (mEH) activity predicted by their genotype (low, intermediate, high).

Results: The studied biomarkers were not able to discriminate between exposed and control individuals, but sister chromatid exchange (SCE) and high frequency cells were influenced by smoking habits. Smokers having fast microsomal epoxide hydrolase activity showed higher SCE frequency (7.61) respect to those presenting intermediate (5.86) or slow (6.65) enzymatic activity.

Conclusions: On the basis of these results, can we suppose the existence of an "intermediate genotype" advantage (at least for induction of SCE)?