HPA-CRCE-019 - an analysis of radon remediation methods

Radon gas in the home is a major source of public radiation exposure and an established cause of lung cancer. A range of techniques are available to reduce high indoor radon concentrations in homes. Information on some 2,700 radon remediation projects has been analysed with the aim of identifying the factors that influence the performance of various remediation methods, including the specific remediation techniques applied, the physical characteristics of the home, the radon level before remediation and who carried out the work. The analysis shows that each method used to reduce radon levels has a range of performance which is influenced by some factors but is independent of others. Each remediation method showed a trend in performance with respect to the initial radon concentration. Higher initial radon concentrations offer greater relative reductions when remediated. However, homes with higher initial concentrations measures were less likely to achieve reductions below the Action Level (200 Bq m). Overall, an active sump system is most likely to offer a substantial reduction, on average 6 fold. Other methods are less effective, reducing levels by a typical factor of about 2. Passive ventilation and sealing are least effective. This analysis does not support firm conclusions about the relative performance of different types of remediators and householders who do ‘DIY’. Typical costs have been estimated with active sumps being the most expensive at around £800. This information will be used to update guidance for householders and others such as contractors, using fact sheets, presentations at radon householder events and the UKradon website.