Factors underlying persistently high radon levels in a house located in a karst limestone region of Ireland – lessons learned about remediation

Radon is a naturally occurring radioactive gas that originates from the decay of uranium in rocks and soils and is linked to some 13% of lung cancer cases in Ireland. Between 1992 and 1999, the Radiological Protection Institute of Ireland (RPII)1 carried out a National Radon Survey (NRS) of Ireland to identify the areas of the country most at risk from high indoor radon levels. Those areas where it was predicted that more than 10% of homes will have radon concentrations above the reference level of 200 Bq/m3 were designated High Radon Areas [1]. During 1999, in response to public awareness work related to the NRS, a homeowner living in a high radon area near Lisdoonvarna in County Clare (Fig. 1) in the southwest of Ireland used the RPII’s radon measurement service to carry out a radon test in her house. A radon concentration of almost 1500 Bq/m3 was identifi ed, compared to the Irish reference level of 200 Bq/m3. In 2004, the householder engaged a radon remediation contractor to reduce radon concentrations. The contractor installed mechanical ventilation to extract radon Factors underlying persistently high radon levels in a house located in a karst limestone region of Ireland – lessons learned about remediation Stephanie C. Long, David Fenton, Chris Scivyer, Eugene Monahan