Radon in groundwater and dose estimation for inhabitants in Spas of the Sudety Mountain area, Poland.

Studies of radon isotope (222)Rn activity concentration in underground water in the Sudety region were performed with the use of the liquid scintillation technique. Waters chosen for investigations were collected in 24 health resorts and towns of the Sudety area from 115 springs, wells and intakes. The (222)Rn activity concentration varied within the range from 4.2+/-0.4 to 1703+/-55 Bq/l. The annual effective doses due to the consumption of (222)Rn with water were calculated for 50 sources of underground spring water or tap water used for consumption. The results were within the range from 0.003 to 1.1 mSv/yr, assuming 0.5 l of tap water per day from which radon is not removed or 0.5 l of mineral spring water consumed daily. The contribution to the effective dose from the inhalation of radon during the daily usage of domestic water substantially increases its effective dose.