ABSTRACT
The exposure to natural sources of ionizing radiation is the most significant contribution to the annual dose received by the general population. The risk of cancer due to radon exposure is increased for smokers The purpose of this work was to perform a review on occupational exposure to radon considering mitigation measures that may be efficiently adopted to decrease the levels of indoor radon in thermal spas. All architectural and constructive solutions that reduce building contact with soil, prevent radon infiltration, and facilitate diffusion into the atmosphere contribute to reducing the risk of reaching hazardous concentrations within the building. It is therefore concluded that all efforts to reduce radon infiltration from the soil are based on active or passive ventilation techniques, mainly soil below ground level, increased soil tightness in contact with the ground and in the increase of the ventilation of the spaces of housing.
