DNA adducts of 1,3-butadiene in humans: relationships to exposure, GST genotypes, single-strand breaks, and cytogenetic end points.

The modulation of 1,3-butadiene (BD)-induced DNA adducts by occupational exposure, glutathione S-transferase (GST) genotypes, single-strand breaks, and cytogenetic end points was studied in 15 workers and 11 controls. The exposed group consisted of 8 smokers and 7 nonsmokers, whereas the control group consisted of 7 nonsmokers and 4 smokers. Among all subjects, the adduct levels in workers lacking GSTM1 were significantly higher than in those who were GSTM1 positive (P = 0.026), and individuals with combined GSTM1(-) and GSTT1(+) genotype had elevated level of adducts compared to that of persons with GSTM1(+) and GSTT1(+) (P = 0.049). The increase in BD-DNA adduct levels in all subjects was significantly related to BD exposure and GSTM1 genotype (linear multiple regression analysis, P = 0.001; P = 0.035). The results suggest that DNA adducts serve as a sensitive and specific biomarker, integrating exposure and host metabolic capacity, although the data are limited to a small number of subjects.