238U, 234U, 226Ra, 210Po concentrations of bottled mineral waters in Italy and their dose contribution

Due to the importance of bottled mineral water in human diet with special regard to children in lactation period, a monitoring of natural radioactivity in some bottled mineral waters produced in Italy was performed. Gross alpha and beta activities and 226Ra, 238U, 234U, and 210Po concentrations were measured. Gross alpha and beta activities were determined by standards ISO 9696 and ISO 9697; for 226Ra determination liquid scintillation was used. The 238U and 234U concentrations were determined by alpha spectrometry after their separation from matrix by extraction chromatography and electroplating. 210Po was measured by alpha spectrometry. The results revealed that the concentrations (mBq L-1) of 226Ra, 238U, 234U, and 210Po ranged from <10.00 to 52.50, from <0.17 to 89.00, from <0.17 to 79.00, and from <0.04 to 21.01, respectively. Uranium and radium concentrations do not reach the relevant recommended derived activity concentration (DWC). For polonium concentration, none of the samples reaches the relevant DWC in the case of adults and children, but one sample exceeds this value for infants. The dose contribution for different classes of age was calculated using the dose coefficient factors reported by EC Directive 96/29 EURATOM and certain annual intake. For children and adult age class, the calculated doses are quite similar and lower than 0.1 mSv y-1; for infants (<1 y) in three cases the calculated dose ranges from 0.11 to 0.17 mSv y-1