Uranium, radium and 40K isotopes in bottled mineral waters from Outer Carpathians, Poland

Radioactivity content in commercially bottled mineral waters from Outer Carpathians was investigated on the basis of 28 samples. Activity concentration results for radium isotopes 226,228Ra, uranium isotopes 234,238U and isotopic ratios 234U/238U were determined. The correlations between investigated isotopes and calculated potassium 40K ions dissolved in water were carried out. The results show a correlation between TDS (total dissolved solids) values and dissolved radionuclides. High correlation coefficients were observed between total radium content and 40K. The isotopic ratio of 234U/238U varies in the range from 1.6 to 7 in all investigated waters which means that there is no radioactive equilibrium between the parent nuclide 238U and its daughter 234U. The effective radiation dose coming from studied radium and uranium radionuclides consumed with mineral water from the Outer Carpathians obtained by a statistical Pole is equal to 4.3μSv/year (58 l/year water consumption) and do not exceed the permissible limit equal to 100μSv/year. Assuming 0.5 l consumption per day, i.e. 182.5 l/year, the effective dose is equal to 13.4μSv/year, what is still below the unit.