Humidity effect on diffusion and length coefficient of radon in soil and building materials

Radon considers as a natural radioactive gas that has a direct effect on human health. It can cause lung cancer while it enters the respiratory tract. As a result, it is necessary to study some parameters that affect its concentrations in soil and building materials. In this research, we have studied the effect of humidity on diffusion coefficient and the length of radon gas in soil and building materials (cement and gypsum) using device (SARAD RTM 1688). The concentration of radon gas was measured at different temperatures and humidity. The SARAD device was connected to the exposure system that was carried out and manufactured by the researchers. After that the coefficient and length of the diffusion of radon was calculated theoretically and experimentally. Results obtained for soil indicated a good agreement between the theoretical and experimentally values that led to making other calculations of the coefficient and the length of the diffusion of radon through other materials that are not studied experimentally or theoretically before. In this research, the results showed that values of the diffusion coefficient and the diffusion length of the radon were decreasing with humidity by ratio of (similar to 0.20) when humidity (0.70) and by ratio (>0.20) when humidity (>0.70). (C) 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)