Urinary 8-Oxo-7,8-dihydro-2'-deoxyguanosine in Tunisian Electric Steel Foundry Workers Exposed to Polycyclic Aromatic Hydrocarbons

In this study, urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), as biomarker of oxidative DNA damage, was evaluated in Tunisian electric steel foundry workers and was associated with polycyclic aromatic hydrocarbon (PAH) exposure. Ninety-three healthy male workers were enrolled in the study; 8-oxodG was assessed by liquid chromatography-triple quadrupole mass spectrometry. Exposure to PAHs was evaluated by measuring 16 urinary PAHs (U-PAHs) and 8 monohydroxylated metabolites (OHPAHs). The median 8-oxodG level for all subjects was 3.20 µg l-1 (1.85 µg g-1 creatinine). No correlation between 8-oxodG and 1-hydroxypyrene or any other OHPAH was found. Significant linear correlations between 8-oxodG and some U-PAHs were found, particularly urinary acenaphthylene (r = 0.249), phenanthrene (r = 0.327), anthracene (r = 0.357), fluoranthene (r = 0.248), and pyrene (r = 0.244). Multiple regression analyses confirmed that urinary phenanthrene, anthracene, and naphthalene (the latter with a non-linear relationship) were predictors of 8-oxodG; job title, but not smoking, was a determinant of 8-oxodG; the variance explained by these models was up to 20%. The oxidative DNA damage assessed by urinary 8-oxodG was moderate and in the range of values reported in other occupational fields or in the general population. The results of this study indicate that the investigated biomarkers of PAH exposure were only minor contributors to urinary 8-oxodG.