Chromosome aberrations in tunnel workers exposed to acrylamide and N-methylolacrylamide.

The aim of this study was to examine chromosome aberrations in 25 tunnel workers exposed to acrylamide-containing grout in injection work. Blood samples were collected from 25 exposed and 25 unexposed tunnel workers matched for age, gender, and smoking habits. Whole blood was cultured for 50-53 hours according to conventional methods. Chromosome damage was scored in 200 metaphases per person on coded slides. The distribution of glutathione S-transferase (GST) genotypes (M1 and T1) was examined for all the workers. Exposure assessment was performed with detailed interviews and questionnaires. The chromosome examinations showed no statistically significant differences between the 25 exposed and 25 unexposed workers for cells with chromosome aberrations or for chromatid breaks, chromosome breaks, and chromosome gaps. The exposed workers had a significantly higher number of chromatid gaps (mean 10.6, SD 5.6) than the unexposed workers (mean 6.4, SD 4.4, P=0.004), but there was no exposure-response relationship. The limited stratum-specific numbers showed that the exposed workers with the GSTM1-/GSTT1-genotype had nonsignificantly higher frequencies of all the effect parameters than the unexposed workers; this finding indicates that individual susceptibility related to the detoxification of acrylamide and N-methylolacrylamide may have played a role in the observed effect. No increase in chromosome breaks or aberrations was observed for 25 workers exposed to acrylamide-containing grout during tunnel work. The increased frequency of chromatid gaps in the exposed workers may indicate a slight genotoxic effect related to exposure to acrylamide or N-methylolacrylamide.