Increased levels of etheno-DNA adducts and genotoxicity biomarkers of long-term exposure to pure diesel engine exhaust

Etheno-DNA adducts are biomarkers for assessing oxidative stress. In this study, the aim was to detect the level of etheno-DNA adducts and explore the relationship between the etheno-DNA adducts and genotoxicity biomarkers of the diesel engine exhaust (DEE)-exposed workers. We recruited 86 diesel engine testing workers with long-term exposure to DEE and 99 non-DEE-exposed workers. The urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and etheno-DNA adducts (epsilon dA and epsilon dC) were detected by HPLC-MS/MS and UPLC-MS/MS, respectively. Genotoxicity biomarkers were also evaluated by comet assay and cytokinesis-block micronucleus assay. The results showed that urinary edA was significantly higher in the DEE-exposed workers (p < 0.001), exhibited 2.1-fold increase compared with the non-DEE-exposed workers. The levels of urinary OH-PAHs were positively correlated with the level of epsilon dA among all the study subjects (p < 0.001). Moreover, we found that the increasing level of epsilon dA was significantly associated with the increased olive tail moment, percentage of tail DNA, or frequency of micronucleus in the study subjects (p < 0.01). No significant association was observed between the epsilon dC level and any measured genotoxicity biomarkers. In summary, epsilon dA could serve as an indicator for DEE exposure in the human population. (C) 2015 Elsevier B.V. All rights reserved.