Methods for radioactivity measurements in drinking water using gamma spectrometry

In this study, three methods to measure activity concentrations of radionuclides through high resolution gamma spectrometry are developed, optimized, and tested on drinking water samples. Two pre-concentration methods (partial evaporation and ion-exchange resins) were optimized for accuracy, precision, detection limits, costs, preparation, and measurements times. A new sampling method for 222Rn was designed and optimized to directly sample water from the tap, reducing and minimizing losses of radon during the sampling. A total number of 85 water samples were collected between 2017 and 2019 in collaboration with two drinking water suppliers in a wide area (~2000 km2) of the Veneto region, northeast Italy. These are the first results of radionuclides activity concentration in drinking water concerning a large extension in the foothill Veneto region. Finally, this study provides a first attempt of determining the spatial distribution and seasonal variations of radon activity concentration in drinking water in the study area.