Home energy efficiency and radon related risk of lung cancer: modelling studyBMJ 2014; 348 doi: https://doi.org/10.1136/bmj.f7493 (Published 10 January 2014) Cite this as: BMJ 2014;348:f7493
- James Milner, lecturer1,
- Clive Shrubsole, research associate2,
- Payel Das, research associate2,
- Benjamin Jones, lecturer23,
- Ian Ridley, senior research fellow24,
- Zaid Chalabi, senior lecturer1,
- Ian Hamilton, lecturer5,
- Ben Armstrong, professor in epidemiological statistics1,
- Michael Davies, professor of building physics and the environment2,
- Paul Wilkinson, professor in environmental epidemiology1
- 1Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, UK
- 2Bartlett School of Graduate Studies, University College London, UK
- 3Department of Architecture and Built Environment, University of Nottingham, UK
- 4Royal Melbourne Institute of Technology, Melbourne, Victoria, Australia
- 5UCL Energy Institute, University College London, UK
- Correspondence to: P Wilkinson
- Accepted 6 December 2013
Objective To investigate the effect of reducing home ventilation as part of household energy efficiency measures on deaths from radon related lung cancer.
Design Modelling study.
Intervention Home energy efficiency interventions, motivated in part by targets for reducing greenhouse gases, which entail reduction in uncontrolled ventilation in keeping with good practice guidance.
Main outcome measures Modelled current and future distributions of indoor radon levels for the English housing stock and associated changes in life years due to lung cancer mortality, estimated using life tables.
Results Increasing the air tightness of dwellings (without compensatory purpose-provided ventilation) increased mean indoor radon concentrations by an estimated 56.6%, from 21.2 becquerels per cubic metre (Bq/m3) to 33.2 Bq/m3. After the lag in lung cancer onset, this would result in an additional annual burden of 4700 life years lost and (at peak) 278 deaths. The increases in radon levels for the millions of homes that would contribute most of the additional burden are below the threshold at which radon remediation measures are cost effective. Fitting extraction fans and trickle ventilators to restore ventilation will help offset the additional burden but only if the ventilation related energy efficiency gains are lost. Mechanical ventilation systems with heat recovery may lower radon levels and the risk of cancer while maintaining the advantage of energy efficiency for the most airtight dwellings but there is potential for a major adverse impact on health if such systems fail.
Conclusion Unless specific remediation is used, reducing the ventilation of dwellings will improve energy efficiency only at the expense of population wide adverse impact on indoor exposure to radon and risk of lung cancer. The implications of this and other consequences of changes to ventilation need to be carefully evaluated to ensure that the desirable health and environmental benefits of home energy efficiency are not compromised by avoidable negative impacts on indoor air quality.
Contributors: The text of this paper was drafted mainly by PW and JM, with contributions from all other authors. PW and JM are guarantors of the work. All authors participated in the design of the study and interpretation of the results. JM, ZC, and PW developed and performed the health impact modelling. CS, PD, BJ, IR, and MD developed and performed the radon modelling and energy calculations. IH analysed the stock data and matched the building models to the stock. BA provided guidance on interpretation of the health model results and sensitivity analysis. All researchers involved in the work had full access to all of the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.
Funding: The research leading to these results received funding from the European Union seventh framework programme FP7/2007-2013 under grant agreement No 265325 (Public health impacts in urban environments of greenhouse gas emissions reduction strategies, PURGE). The funders had no role in study design, in the collection, analysis, and interpretation of data, in the writing of the report, and in the decision to submit the paper for publication. All researchers involved in the work were independent of the funder.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: Not required.
Data sharing: No additional data available.
Transparency: The lead author affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been explained.
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