In radon pollution control, materials with radon adsorbing characteristics will significantly affect the migration and release of radon. In this paper, radon adsorbing medium (activated carbon particles) is proposed to be added to the building foundation granular filling layer as a radon adsorbing layer to alleviate indoor radon pollution. Radon exhalation rate is an important physical quantity used to evaluate the radon exhalation capacity of materials. This study compared the measurement results of radon exhalation rate on the radon adsorbing media surface by the traditional Closed-loop Meth...