title: State of the art of practical countermeasures and techniques and cost-benefit considerations.
abstract: The doses and risks from exposure to high concentration of radon in indoor air are discussed in the perspective of other risks in modern life as an average for the population and as individual risk to the inhabitants of houses with very high concentration of radon. Interpretation and application of ICRP publication 39 are discussed. It is suggested that in existing structures with infiltration of radon from the soil remedial action be based on the principle of first trying to caulk obvious and accessible openings and, if this is not possible, installing a sub-floor depressurising system. Ventilation of the building is used only if these methods are not effective. Radon exhaling from building materials is controlled by ventilation. In new construction, materials with high activity of radium should not be used and the design should be modified to prevent infiltration of soil gas.
mesh_terms: D003252:Construction Materials; D003362:Cost-Benefit Analysis; D004781:Environmental Exposure; D006798:Housing; D006801:Humans; D011827:Radiation; D011834:Radiation Monitoring / Q000191:economics*; D011886:Radon / Q000032:analysis*; D012306:Risk; D012987:Soil / Q000032:analysis*
chemical_list: D012987:Soil; D011886:Radon