Radiological characterization of Portuguese natural mineral water

Abstract

Natural mineral waters used in therapeutic treatments present diverse chemical composition which can include natural radionuclides, such as radon, increasing the risk of exposure to natural radiation for both workers and bathers. The purpose of the present study was to evaluate the radon concentration in natural mineral waters of 17 Portuguese thermal establishments. The evaluation was carried out between 2013 and 2015 in several places of each thermal establishment. An analysis of the compliance between the obtained values and the existing legal requirements for the different parameters concerning radon concentration in water was made. The results showed the presence of anomalous values both higher than the reference level and the action level. Approximately 50% of the obtained results are higher than the reference level recommended by the EU, while 20% of the results exceeded the action level. These results may also imply high concentrations of indoor radon (and hence occupational exposure to radon), since the natural mineral water will be a continuous source of this radionuclide. The high values obtained in some cases are worrying and show the need for a more detailed and extensive study, both in space and time.