Natural radioactivity of some spring and bottled mineral waters from several Central Balkan sites, as a way of their characterization

Abstract

In this work, a study of the radioactive content of some spring and bottled mineral waters originating from metamorphic rock areas was carried out. A high content of radium isotopes ( 226 Ra, 228 Ra), was found by radiometric analysis in the spring waters: Studenica ( 226 Ra: 289 mBq/L),^ibutkovica ( 226 Ra: 92, 4 mBq/L, 228 Ra: 610 mBq/L), and Crni Guber ( 226 Ra: 120 mBq/L, 228 Ra: 1170 mBq/L). On the other hand, the radiochemical results showed a higher concentration of 238 U in the bottled mineral water samples (dissolved uranium concentrations were from 0.21 mBq/L, for "Kopaonik" to 71.5 mBq/L fo "Skadarska") than in the spring water samples (dissolved uranium concentrations were very low » 10 mBq/L). The concentrations of all the present naturally occuring radionuclides: 238 U, 234 U, 232 Th, 230 Th, 228 Th, 228 Ra and 226 Ra were determined by alpha/gamma spectrometric analysis. The activity ratios 234 U/ 238 U, 226 Ra/ 230 Th and 228 Th/ 232 Th, 228 Ra/ 228 Th were calculated and are discussed as an indication of the radioactive disequilibrium in bothe the 238 U and 232 Th radioactive series. The high contents of radium isotopes with respect to the equilibrium values expected from the respective parents 232 Th/( 232 Th series) and 230 Th ( 238 U series) found in the spring water samples is the main evidence for the existence of significant radioactive disequilibrium in both the radioactive series.

Spatial distribution of the 226Ra activity concentrations in well and spring waters in Serbia and their relation to geological formations

“…Barker and Johnson (1964) and Wollenberg (1975) pointed out the higher solubility of radium in presence of aqueous carbonates, probably indirectly due to the stronger leaching of alkaline-earth cations by CO 2 -rich acidic waters rather than due to RaCO 3 0 complexing (Michard et al, 1978). In Serbia, the enrichment of spring waters in 226 Ra (2.28 Bq L − 1 ) in the limestone region (Studenica), where radium is more soluble in CO 2 -rich waters, was reported by Joksić et al (2007). Although the 226 Ra activity concentrations in some waters exceed the level of 1 Bq L − 1 , the majority of these waters are used only for balneological purposes through hydrotherapy.…”