Assessment of Age-Dependent Radiation Dose and Toxicological Risk of Uranium in Ground Water around Uranium Mines in Sikar, Rajasthan

Uranium concentration in forty-six groundwater samples collected from the region near the uranium deposits in the Royal village of Sikar district, Rajasthan, is determined using the LED fluorimetry technique. Age-dependent annual effective dose, radiological, and chemical toxicity risks are calculated to assess health risks associated with the groundwater for the people living in the nearby area. Uranium concentrations of different samples vary from 4.79-266.28 mu g/L with an average value of 74.36 mu g/L Overall 69% and 43% of samples exhibit uranium concentrations greater than recommended limits of WHO and AERB, respectively. Excess cancer risk values lie in the range from 1.36 x 10-5-7.54 x 10-4and 2.10 x 10-5-1.17 x 10-3 with mean values of 2.11 x 10-4 and 3.26 x 10-4 for mortality and morbidity, respectively. LADD value lies in the range of 0.35 mu g/kg/day to 19.51 mu g/kg/day with a mean value of 5.44 mu g/kg/day. The hazard quotient value for 43.4% and 84.7% of samples is greater than unity according to AERB and WHO standards, respectively. The uranium retention and effective radiological dose to various body organs are estimated using biokinetic modelling. Physico-chemical parameters and their correlation with uranium concentration are also evaluated. A positive correlation is found between TDS and uranium concentration.