Concentration of 226Ra in Iranian Bottled Mineral Water

In this work the concentration levels of 226Ra were measured in 42 samples related to 14 types of bottled natural mineral water commercially available in market. The applied method for this measurement was emanation method with a minimum detection limit of 2 mBq l-1. After adjusting the pH below 2 by concentrated HCl, the radium was co-precipitated with barium and lead as sulfate. The precipitate was dissolved in alkaline EDTA (C10H14N2O8.2H2O) and placed in 20ml bubbler. The bubbler was sealed and stored for 21 days at 5oC for ingrowth of 222Rn. For calculation the committed effective dose for adults drinking 40 l y-1 of bottled mineral water, the ingestion dose conversion coefficients from the IAEA publications is used. Concentration of 226Ra ranged from 2.0 to 12.3 mBq l-1. In one case 12.3 mBq l-1 was measured, which provides 0.138 µSv committed effective dose for adults in the case of consumption rate of  40 l y-1.