Rapid Responses to:

RESEARCH: Alastair Gray, Simon Read, Paul McGale, and Sarah Darby Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them BMJ 2009; 338: a3110 [Abstract] [Full text]

Rapid Responses: Submit a response to this article

Rapid Responses published:

Carefully Targeted Radon Reduction Strategies are More Appropriate

Antony R Denman, Paul S. Phillips, Thomas Coskeran, Christopher J. Groves-Kirkby, Robin G.M. Crockett, and Roger Tornberg   (16 January 2009)

Carefully Targeted Radon Reduction Strategies are More Appropriate 16 January 2009
Antony R Denman, Visiting Researcher School of Applied Sciences, The University of Northampton, Boughton Green Road, Northampton, NN2 7AL, Paul S. Phillips, Thomas Coskeran, Christopher J. Groves-Kirkby, Robin G.M. Crockett, and Roger Tornberg Send response to journal: Re: Carefully Targeted Radon Reduction Strategies are More Appropriate	Dear Sirs, We were interested to read the paper by Gray et al.(1), who assessed the cost-effectiveness of domestic radon remediation programmes in England, using the “cost per QALY gained” measure of cost-effectiveness, a measure we have also adopted in our published work(2,3,4). Two of us were co-authors with Gray on the first paper on this topic, and our group has continued to study radon remediation programmes in Northamptonshire, UK, and published a number of papers on aspects of this topic, culminating in a major review of the influences on cost effectiveness in our series at the International Radiation Protection Association International Conference in Buenos Aires in October 2008(5). We have also studied, and published work on, the impact of changing the action level for existing houses(6), but, in contrast to Gray et al., we found that cost-effectiveness was optimal in our series in the range 200 to 300 Bq. m-3. Another strand of our work has concluded that there is an irreducible minimum radon level in houses studied after remediation, which we postulate is due to radon leaching from building materials. In our series this was 66.3 Bq. m-3, while Gray et al. note that the average domestic radon level across the UK is 21 Bq. m-3. The cause of the higher residual radon level in our series needs to be an area of further study, but possible causes include Northamptonshire being a high radon area, the design of the houses, or the choice of building materials used. In any case, the higher residual radon level is likely to be the source of the difference between our results and those of Gray et al. Given our results, we have concluded that for Northamptonshire, at least, it was not cost-effective to lower the current UK Action Level. Crucially, if our finding of a higher residual radon level is duplicated in other parts of the country, then this will mean that in these areas, too, it would not be cost-effective to lower the action level. Moreover, in our series 28 % (24/86) of houses had residual radon levels over 100 Bq. m-3. If an Action Level of 100 Bq. m-3 were applied these householders would fail to reduce radon levels further, no matter how much additional effort and money they would deploy. Gray et al. make much of the number of cancers occurring in the public in houses in the range 100 to 200 Bq. m-3 but it should be remembered that this is a small risk to a large number of people, and a large number of houses need to be remediated – again with the proviso that the radon level may not be reduced much if at all in some. For the few people living in houses with very high radon levels, (and 49,000 Bq. m-3 has been measured in an Irish house(7), with levels approaching this also found in Cornwall and Northamptonshire), it is a question of individual risk. Remediation in these cases results in an individual risk reduction of well over 95 %. This, together with the finding that fewer smokers remediate, which we first reported in a small scale survey in 2005(8), suggests to us that there is much value in careful targeting of remediation programmes of existing houses, and of smokers, to ensure that those most at risk take action. A further significant conclusion in the paper by Gray et al. was that basic radon precautions were cost-effective in new homes built throughout England, and that this policy should replace the current UK policy of targeting new homes in radon Affected Areas, such as Northamptonshire. One of their assumptions was that, on average, such precautions reduced radon levels by 50 %, a figure given by Naismith(9). Although not explicitly stated in the paper, this assumption means that some new houses will have radon levels above the current UK Action level of 200 Bq. m-3. We have previously confirmed this failure of basic radon precautions in our study of new homes built in Northamptonshire10 where, despite remediation measures, one house in our series had a radon level of 960 Bq. m-3. For this reason, we would contend that, as basic radon protection of new houses leaves some occupants at greater risk, these measures must be accompanied by a requirement to test radon levels in all new homes, and then remediate further those found above the Action Level, using sump and fan or other technology. This will, of course, increase the costs of such a programme, but will also increase the health benefits, and ensure that no individuals are at risk. It may, however, place the overall cost- effectiveness outside the NICE guidance, although the exact outcome will depend on the balance of costs and benefits arising from the programme of testing and additional remediation. Our study(10), which considered a much larger number of houses than Naismith(9), also showed a significant failure rate of the membranes used for such protection, of around 60 to 70 %. This failure rate is the proportion of new houses with radon levels above the action level relative to existing homes above the action level in the same area, and occurs despite the presence of radon protection in the new homes. Two Irish studies have found similar failure rates, with at least two homes having radon levels over 1300 Bq. m-3, again despite basic protection(11). We did not publish a value for the mean radon reduction in our series, but a re- analysis suggests that the reduction in our series was only 16 %, considerably lower than the value assumed by Gray et al. Whilst we concluded that the provision of basic radon protection in new homes in high-radon areas, such as Northamptonshire (3), is likely to be cost-effective, we suggest that the current failure rate of radon-proof membranes precludes this conclusion for a nationwide policy, even without the requirement to test radon levels. Our group has also analysed an alternative strategy for protecting new homes, namely to provide no protection in new properties, but require testing, and subsequent remediation only of those properties above the action level. This latter strategy was shown to be much more cost-effective than requiring membranes to be installed in the new homes (4). We are currently working on the assessment of a wider range of policy options for new homes. Our initial analysis, as yet unpublished, suggests that the proposed alternative above, as well as other alternatives, could be more cost-effective than current policy. Putting resources where they will yield substantial health benefits could, therefore, be a better way forward than requiring the nationwide use of radon remediation measures often in properties where, we can be fairly sure, they will have little or no beneficial effect on the health of residents. These challenging issues remain at the heart of the debate on how to construct a cost-effective policy that protects occupants of new and existing properties against the effects of radon. Yours sincerely, A.R. Denman, P.S. Phillips, T. Coskeran, C.J. Groves-Kirkby, R.G.M. Crockett, R. Tornberg References 1. Gray A, Read S, McGale P, Darby S. Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them. BMJ 2009;338;a3110. doi:10.1136/bmj.a3110 2. Coskeran T, Denman A, Phillips P, Gillmore G, Tornberg R. A new methodology for cost-effectiveness studies of domestic radon remediation programmes: Quality-adjusted life-years gained within Primary Care Trusts in Central England, Science of the Total Environment, 2006; 366 (1): 32- 46. 3. Coskeran T, Denman A, Phillips P, Tornberg R. The Cost- Effectiveness of Radon-proof Membranes in New Homes: A Case Study from Brixworth, Northamptonshire, UK; Health Policy; 2007; 8(2-3), 195-206. 4. Coskeran T, Denman A, Phillips P, Tornberg R. A Cost-effectiveness Analysis of Radon Protection Methods in Domestic Properties: A Comparative Case Study in Brixworth, Northamptonshire, UK. Journal of Environmental Radioactivity; 2006; 91(1-2),73-89. doi:10.1016/j.jenvrad.2006.08.005 5. Denman A, Groves-Kirkby C, Coskeran T, Phillips P, Crockett R, Allison C, Tornberg R. A Review of the Factors Affecting the Cost Effectiveness and Health Benefits of Domestic Radon Remediation Programmes; Full Paper in the Proceedings of the 12th International Congress of the International Radiation Protection Association, October 19 -24, 2008, Buenos Aires, Argentina (CD-Rom) 6. Denman A, Coskeran T, Phillips P, Crockett R, Tornberg R, Lowering The UK Domestic Radon Action Level To Prevent More Lung Cancers – Is It Cost Effective ? Journal of Radiological Protection, 2008; 28(1), 61-71 doi:10.1088/0952-4746/28/1/003 7. Organo C, Murphy P. The Castleisland Radon Survey-follow--up to the discovery of a house with extremely high radon concentrations in County Kerry (SW Ireland). J Radiol Prot. 2007; 27(3):275-85. 8. Denman A, Phillips P, Tornberg R, Groves-Kirkby C. Analysis of the Individual Health Benefits Accruing from a Domestic Radon Remediation Programme;. Journal of Environmental Radioactivity; 2005; 79(1), 7-23 9. Naismith SP. Durability of radon remedial actions. Radiation Protection Dosimetry 1997; 71(3):215-218. 10. Groves-Kirkby C, Woolridge A, Denman A, Phillips P, Crockett R, Tornberg R. Radon Mitigation in Domestic Properties and its Health Implications – A Comparison Between During-Construction and Post- Construction Remediation, Environment International,2006; 32(4), 435-443 doi: 10.1016/j.envint.2005.10.004. 11. Colgan P. Encouragement and enforcement - has the time come to legislate. Talk at Conference: Radon Risk - time for more effective action. London, U.K. 29-30 Jan, 2007. Full paper at www.rpii.ie/Download/IBC%20Presentation.pdf Competing interests: None declared