Determination of Uranium Concentration in Human Urine for Selected Regions in Iraq Using Laser-Induced Kinetic Phosphorimetry and CR-39 Nuclear Track Detector

Urine assay is the preferred method for monitoring accidental or chronic internal exposure of uranium in human body. In the present study, two typical methods have been used for determination of uranium in human urine for occupational mining workers and residents of selected regions in Iraq. The main technique is kinetic phosphorescence analysis (KPA). This technique is based on exciting an aqueous solution of uranium using a pulsed dye nitrogen laser source, and measures the emission intensity over time to determine the luminescence decay profile.Calibration of the system was carried out before analysis utilizing standards of known uranium concentrations to construct the calibration curve between the initial luminescence intensity and uranium concentration. The assay calibration curves are linear and cover the range of uranium concentrations between 0.05 µg/l and 100 µg/l. The limit of quantification in which uranium in urine could be accurately measured above the background was determined to be 0.01 µg/l.Uranium concentration in urine of all subjects ranged from 0.41 to 5.26 µg/l with an average of 1.315 ± 0.730 µg/l. Higher uranium concentrations were found in the urine of Al-Qaim uranium purification previously workers. The results showed significant correlation with working place and employment duration in Akashat mine and Al-Qaim fertilizer complex. The mean values of different age groups were found to be proportional to age up to 60 years. In addition, the results also show that uranium concentration in urine of Akashat mining area, Tall al-Ragrag and Al-Jesira residents are higher than those living in Al-Qaim. Finally, it has been found that uranium excretion in urine of male is higher than female for each age group.In order to compare the results all samples were also analysed using the fission track analysis (FTA) with CR-39 solid state nuclear track detector. The results of the comparison demonstrated that the two different techniques were capable of making the measurements, although not with equal degree of bias and uncertainty. It is observed that the kinetic laser phosphorescence technology is more suitable for analysis of uranium in urine samples having high concentration than the fission track technique.