Development of a new tool to simultaneously measure soil-gas permeability and CO 2 concentration as important parameters for geogenic radon potential assessment.

This study assessed the geogenic radon potential using PECAME, an innovative tool designed to simultaneously measure soil-gas permeability and CO 2 concentration - two key parameters for understanding radon transport in soil. Comparative field studies using the RADON-JOK device in various geological settings in Japan and Poland demonstrate the effectiveness of PECAME. These studies reveal a strong correlation between PECAME and RADON-JOK, with an R 2 value of 0.94 for flow rate of 3.5 dm 3 min - 1 . Since the soil-gas Rn concentration and permeability were measured simultaneously, the geogenic radon potential was calculated. Most measured points fall within the low to medium radon index zones, with two exceptions near active faults located in the high zone. Therefore, permeability and CO 2 measurements using PECAME may facilitate further research in Japan to develop a comprehensive geogenic radon potential map.