238U, 234U and 226Ra concentrations in mineral waters and their contribution to the annual committed effective dose in Turkey

Activity concentrations of U-234, U-238 and Ra-226 in mineral waters were determined on the basis of nine water bottling facilities using alpha particle spectrometry. The mineral water samples were collected from three geographic regions of Turkey. The radiochemical separation used in the uranium analysis is based on the isolation of uranium radioisotopes from other radionuclides such as Th, Am, Pu and Np using UTEVA resin. Alpha sources were prepared using electrodeposition method. The activity concentration of Ra-226 was determined after deposition on a membrane using BaSO4 co-precipitation method. The activity concentrations (mBq L-1) of Ra-226, U-238 and U-234 ranged from < 0.56 to 165, from < 0.42 to 439 and from < 0.42 to 464, respectively. The measured activity concentrations were used for the calculation of the average total annual effective ingestion doses for children and adults. The committed effective doses were calculated for three different scenarios according to mineral water consumption rate. In the most extreme scenario (for age group 12-17), all water samples except MW1 and MW2 cause annual committed effective doses below the reference level (0.1 mSv year(-1)) recommended by World Health Organization (WHO).