Ra-226 and natural uranium in Argentinian bottled mineral waters

Concentration levels of Ra-236 and natural uranium have been analysed in most of the bottled mineral waters commercially available in Argentina. Ra-236 was determined by Rn-222 emanation and liquid scintillation counting and natural uranium by a fluorimetric procedure. Concentrations up to 40 mBq.l(-1), with a geometric mean of 3.4 mBq.l(-1) were observed for Ra-226 and for natural uranium a geometric mean of 1.3 mu g.l(-1) with values ranging from 0.04 to 11 mu g.l(-1) were measured. These values are compared with concentrations reported for other countries and reference values accepted for drinking water. Based on the consumption rate and the measured concentrations, a collective committed effective dose of 1.3 man.Sv.y(-1) for the ingestion of both natural radionuclides analysed and an average individual committed effective dose of 0.4 mu Sv.y(-1) were obtained.