In the last years, the requirements included in the Council Directive 2013/51/Euratom have led to an increase of radon concentration measurements in drinking waters. Even if the Council Directive, and so the Italian legislation, does not apply to natural mineral waters, two main reasons suggested the idea of monitoring mineral concessions. Italy is the first country in Europe for mineral water consumption, and besides, many mineral concession owners allow also consumers to fill bottles and containers, intended for transport and subsequent consumption, directly from the fountains within the plant.
The aim of the paper is to present methods and results of the first survey addressing the measurement of radon concentration in the mineral spring waters in Lazio region, Italy.
The measurements have interested 20 different mineral waters and have been carried out by using three distinct measurements chains, each composed by an ionization chamber detector, and a proper degassing circuit. The sampling was performed within the plants of the suppliers, directly from the fountains accessible to consumers. Two different sampling methods have been considered for each spring in order to evaluate if the containers filling methods could influence the dissolved gas degassing and consequently the measured radon concentration.
The results show that 10% of mineral spring water sources returned radon concentrations higher than the parametric value, 100 Bq L-1. The sampling procedure slightly affects radon content, suggesting the relevance of containers filling methods in radon degassing. Previous studies referring to non-mineral waters of Lazio region have been finally considered and compared to results of the survey
