Significant reduction in indoor radon in newly built houses.

Results from two national surveys of radon in newly built homes in Norway, performed in 2008 and 2016, were used in this study to investigate the effect of the 2010 building regulations introducing limit values on radon and requirements for radon prevention measures upon construction of new buildings. In both surveys, homes were randomly selected from the National Building Registry. The overall result was a considerable reduction of radon concentrations after the implementation of new regulations, but the results varied between the different dwelling categories.

Outdoor thoron and progeny in a thorium rich area with old decommissioned mines and waste rock.

Radon (Rn), thoron (Rn) and their decay products may reach high levels in areas of high natural background radiation, with increased risk associated with mining areas. Historically, the focus has mostly been placed upon radon and progeny (RnP), but recently there have been reports of significant contributions to dose from thoron progeny (TnP). However, few direct measurements of TnP exist under outdoor conditions.