Radon and its radioactive progenies in indoor places are recognized as the main sources of public exposure from the natural radioactivity. Alpha emitted by this radioisotope and other radiation emitted from its progenies increase the absorbed dose in respiratory and digestion systems, which may cause cancers. The tap water used for drinking and other household uses can make variable contributions to the indoor radon level. This study has provided data on radon and radium concentrations in water samples of Shirvan region in Iran. Radon and radium concentration of the water samples have been measured by PRASSI system. The results show that 5 samples have radon concentration higher than 10 kBq/m3 as normal level, and radon in 3 samples are near normal level.
