Lifetime risk assessment of Radium-226 in drinking water samples

Background: One of the most significant radionuclides in natural drinking waters is 226Ra and its decay products. It is potential of health problems, including cancer risk. In this study, the effect of 226Ra concentration in 28 drinking water samples collected from the North Guilan province was investigated. Materials and Methods: The activity concentrations of 226Ra were measured by using of radon emanation method and Pylon AB-5 radon scintillation detector. The annual effective dose distribution by age groups, radiological risk and chemical toxicity risk were calculated in drinking water. Results: The activity concentration results range from a low limit of detection (LLD) 2.0±0.1 mBq l-1 to 38.2±2.4 mBq l-1. Also, the annual effective dose distribution by age groups estimated results were from 1.8×10-6 Sv y-1 for adults to 1.5×10-5 Sv y-1 for infants. The radiological risk assessment results were 1.06×10-6 to 2.03×10-5 for morbidity risk, 7.32×10-7 to 1.40×10-5 for mortality risk. The chemical toxicity risk results obtained from 1.08×10-1 to 5.63×10-3. Conclusion: The activity concentration level of 226Ra in all drinking water samples were less than the recommended level WHO for drinking water 1000 mBq l-1. Meanwhile, annual effective dose level, cancer morbidity, mortality risk and life annual daily dose due to consumption of selected drink water samples were less than the standard limit.