Measurement of uranium concentrations in urine samples of adult healthy groups in Najaf governorate with estimation of urine concentrations of 8-OHdG compound as biomarker for DNA damage

Abstract

In this study, 88 healthy adults in Al-Najaf governorate of Iraq have been divided into three groups according to the type of exposure to radiation including environmentally uranium exposures n=29 (G1), occupationally exposures n=27 (G2), and non-uranium exposures n=32 (G3). All groups were subjected for estimation of uranium concentration in urine samples using CR-39 SSNTD method beside measurement of urine concentrations of 8-OHdG compound as a biomarker for oxidative DNA damage using Elisa technique. Reactive oxygen species produced under the effect of many causes including ionizing radiation exposure, (0 H)free radical induced the formation of 8-OHdG compound from cellular and mitochondrial DNA through attack of C-8 in purine ring of guanine base. The results showed that mean values of uranium concentration were (1.836±0.426 μg/L), (2.02±0.404 μg/L) and (1.755± 0.437 μg/L) for group1, group2 and group3, respectively. While mean values for 8-OHdG were (49.810±15.484 ng/ml), (47.717±14.232ng/ml) and (46.769±14.249ng/ml) for the three groups, respectively. No significant statistical differences were recorded between all data obtained. These results suggested the presence of uranium pollution in all groups including the non-exposed group as compared with reference value of (WHO, 2004). Results also demonstrate the presence of DNA oxidative damage in all groups according to concentration levels of 8-OHdG in urine samples. Therefore, the uranium pollution in urine samples of the examined groups indicate the presence of chronic low dose radiation source in Najaf governorate, which might be the cause of DNA damage as reflected by the urinary levels of 8-OHdG compound.