Does groundwater flow effect geogenic radon potential?

Nohara, Tsuyoshi   ; Takesue, Norito ; Sakoda, Akihiro   

Radon is a radioactive gas that is exhaled from rocks and soils, and is generated over a time scale of tens of thousands of years by the radioactive decay of uranium and radium. Smoking and radon are the main causes of lung cancer, and based on the WHO recommendation in 2009, the natural conditions of the geogenic radon potential and the artificial conditions related to indoor radon, which are the main factors of radon exposure, have been examined in Europe. Although indoor radon concentration in Japan is low in the world, and it has been reported that indoor radon concentration increases due to the use of well water, and it is necessary to prioritize investigations on high geogenic radon potential points considering radon concentration in groundwater. The purpose of this study is to confirm the uneven distribution of high radon potential points in the radon spring area, and to investigate the possibility that groundwater flow increases the underground radon potential. Results of field measurements of ambient gamma-ray dose rate, radon exhalation rate and underground radon concentration are reported in some radon spring areas.