Global DNA methylation and oxidative stress biomarkers in workers exposed to metal oxide nanoparticles

[Display omitted] •Global methylation and oxidative DNA damage levels in nanomaterial handling workers were assessed.•8-isoprostane in exhaled breath condensate of workers exposed to nanoparticles was higher.•8-OHdG was negatively correlated with global methylation.•Exposure to metal oxide nanoparticles may lead to global methylation and DNA oxidative damage. This is the first study to assess global methylation, oxidative DNA damage, and lipid peroxidation in workers with occupational exposure to metal oxide nanomaterials (NMs). Urinary and white blood cell (WBC) 8-hydroxydeoxyguanosine (8-OHdG), and exhaled breath condensate (EBC) 8-isoprostane were measured as oxidative stress biomarkers. WBC global methylation was measured as an epigenetic alteration. Exposure to TiO2, SiO2, and indium tin oxide (ITO) resulted in significantly higher oxidative biomarkers such as urinary 8-OHdG and EBC 8-isoprostane. However, significantly higher WBC 8-OHdG and lower global methylation were only observed in ITO handling workers. Significant positive correlations were noted between WBC and urinary 8-OHdG (Spearman correlation r=0.256, p=0.003). Furthermore, a significant negative correlation was found between WBC 8-OHdG and global methylation (r=−0.272, p=0.002). These results suggest that exposure to metal oxide NMs may lead to global methylation, DNA oxidative damage, and lipid peroxidation.