Radon was determined in spring waters at different points of north-eastern Spain, in the region of Catalonia.
A procedure was applied for the determination of 222Rn in water samples using liquid scintillation counting (LSC).
The possible origin of the 222Rn was correlated through the analysis of its parents (226Ra, 234U and 238U).
The annual effective dose was calculated of all of the radionuclides measured in the spring water samples.