226Ra in geothermal and bottled mineral waters of Hungary

Abstract Geothermal waters have been used on a large scale for bathing, drinking and medical purposes, while the consumption of bottled mineral waters is increasing. In this work, radon and radium activity concentrations of thermal and bottled mineral waters, originating from different regions of Hungary, were studied by different radioanalytical methods. It was found that the thermal springs, which supply the world famous baths of Budapest along the right riverside of the Danube, have high 222 Rn and 226 Ra activity concentration: up to about 100 and 1 kBq m −3 , respectively. The radium content of some investigated geothermal waters found in the NE region of the Great Hungarian Plain is even higher: up to several kBq m −3 . The 226 Ra content of bottled mineral waters, commercially available in Hungary, was determined by gamma-spectrometric method, applying radiochemical separation. The highest value exceeded 2 kBq m −3 in the case of the Apenta mineral water, which is a popular brand in Hungary, as well as in Europe and North America.