ABSTRACT
Radon 222Rn in deep borehole water of Gdańsk Hydrogeological Region has been quantitative determined. This region is located in east part of Gdańsk Voivodship and in west part of Elbląg Voivodship including Żuławy. The measurements were performed using alpha liquid scintillation counting method. Only in some case the concentrations of 222Rn in investigated samples exceed recommended limit 11 Bq/1.