Comparison of radon (Rn-222) concentration in Portugal and Finland underground waters

Intercomparison results of Radon (Rn-222) measurements using two phase liquid scintillation counting (LSC) technique was performed. The results obtained are in good agreement with the assigned levels. Several water samples from different Portuguese underground catchments were also analyzed. In general, the waters showed acceptable Rn-222 levels, however, 20% presented concentrations between 500 and 1000 Bq L−1 and 5% higher than 1000 Bq L−1. In Finland, the mean Rn-222 concentration obtained in drilled wells was 460 Bq L−1 and in wells dug in soil 50 Bq L−1. Approximately 10% of drilled wells exceeded a radon concentration of 1000 Bq L−1.