Intercomparison exercises as a tool for improving the quality of radiochemical measurements in drinking waters - Radon-222 determinations.

The results of a European intercomparison on Rn in water were analyzed to evaluate the performances of standard and non-standard methods. Then, results obtained with a specific LSC method (ISO 13164-4) based on two-phase liquid scintillation counting which has been employed by a considerable number of participants were examined in detail. This ISO LSC method was proved to be accurate, reliable and its reproducibility has been also sufficient. The intercomparison could be used as a collaborative study and the analysis of its results allowed to estimate the method reproducibility.