Estimation of Natural Radioactivity in Underground Water Sources for Personal Use in Zhytomyr City and Its Suburbs

The article reviews recent research and includes data analysis on natural radioactivity in 49 artesian drinking water samples from private sources in Zhytomyr city and its suburbs. The measurements aim to support the installation of modern water purification systems, especially for removing natural radionuclides. A liquid scintillation spectrometer and an HPG γ-spectrometer were used to measure the specific activity of radon, total uranium (∑U), ²²⁶ Ra, and ²²⁸ Ra isotopes. LSC-based methods were utilized for measuring ²²² Rn and ²²⁶ Ra in a two-phase sample; U is extracted using a 20% solution of TBP in o-xylene to determine the ∑U activity concentration via the LSC technique. Recently developed methods have been applied to concentrate water samples using ion-exchange resins, thereby improving the detection limits for uranium (U) and radium (Ra) isotopes. These simple step methods rely on straightforward procedures and commonly available materials, including widely accessible ion-exchange resins.New data on natural radionuclide activity concentrations in water, accumulated over the past three years, include ²²⁸ Ra. We compared it with data from the previous three-year set of similar water sample studies and with data from studies conducted on a wide range of drinking water sources in the Zhytomyr region from 1990 to 2019. ²²² Rn, ²²⁶ Ra, and ∑U data for the considered time intervals were found to be compatible and agreed with each other. The ²²⁶ Ra to ²²⁸ Ra ratio data varies mainly within the range of 0.5 to 3.5.Radiation doses were calculated as a lifetime average annual dose, taking into account age-dependent dose coefficients and corresponding weighting factors. When assessing potential radiation doses, focus is placed on radium isotopes, which contribute most to the radiation dose. The activity concentration of ²²⁸ Ra ranged from 3 to 500 mBq/L, corresponding to an irradiation dose of 2.7 to 452 µSv per year, which accounts for up to 96.2% (median – 65.6%) of the total irradiation dose from uranium and radium isotopes ingested through the consumption of potable water.