The cost effectiveness of radon remediation programmes in hospitals, schools and homes in radon affected areas in the UK

Radon gas is now considered to be a health hazard when found in excessive amounts in the builtenvironment. The levels of radon vary greatly, with some geographical areas having very highlevels. In the United Kingdom, Northamptonshire was declared an Affected Area in 1992, and itwas at this stage that our group first started studying radon levels and the steps taken to reducethem.The radon levels both before and after remediation were studied, together with the number ofoccupants of affected rooms, and their pattern of occupation. The totals costs of the programmewere recorded, including the survey using etched track detectors to find the affected room, andwork done to reduce radon levels. This analysis provided a total cost of the remediationprogramme per dose saved.This analysis was carried out, first for Health Service properties in Northamptonshire, and then forschools and domestic properties. Comparison of the three programmes showed that the programmein schools was the most cost effective, but that a completed programme in domestic propertieswould be almost as effective. However, in the UK, only 10 % of those who discover raised radonlevels have so far organised remedial work, greatly reducing the cost effectiveness of the domesticremediation programme. It was found that it was four times more expensive to remediate HealthService properties compared to a completed programme in domestic properties. The results wereclose to theoretical predictions made for domestic properties in other countries.All the programmes could be justified when compared to the National Radiological ProtectionBoard (NRPB) initiative to reduce patient dose from dental X-Rays. However, if the uptake ofhouseholders was less than 10 %, a domestic remediation programme was excessively expensive.The analysis has now been extended to series of houses in North Oxfordshire, and Somerset, whichhas allowed a comparison of cost effectiveness for areas with different percentages of housesabove the domestic Action Level of 200 Bq m-3.As expected, it is more cost effective to target areas with higher percentages of houses above theAction Level. More importantly, the percentage of householders who find raised radon levels andthen organise remediation is critical. Programmes to reduce domestic radon levels in areas where 2% or less of houses are above the Action Level are difficult to justify financially unless a highhouseholder response is achieved.