Health effects of radon exposure

2 June 2009

Radon - a naturally occurring gas - is the major source of human exposure to ionising radiation in the United Kingdom and is responsible for an estimated 1,100 lung cancer deaths a year; most of which occur in current or ex-smokers¹.

Following an in-depth review of the latest scientific evidence, the HPA's independent expert Advisory Group on Ionising Radiation has recommended that the Agency should place greater emphasis on reducing the UK average indoor radon concentration. The Advisory Group recommends a lowering of the radon Action Level - the point at which the Agency advises homeowners take steps to reduce indoor concentrations of radon - from 200 Bq m-³ to 100 Bq m-³ in areas known to have high concentrations of radon.

In addition, the Advisory Group also recommends that radon control measures in new buildings, currently required only in high radon areas, should be considered in most if not all of the UK.

Advisory Group chairman, Professor Bryn Bridges, OBE, said: "We have reviewed the risk of lung cancer from exposure to radon gas in the home using all sources of information. It now seems appropriate to move towards an approach that reduces the average exposure across the whole country.

 "A health economics analysis shows that several options could be cost effective. For example, cost benefit analysis shows that preventative measures such as a membrane under the floor in new homes would be justified throughout the entire country rather than just in specific areas as at present."

The Advisory Group indicates that the benefits of taking remedial action in existing homes are sensitive to a number of factors including the cost of identifying homes with relatively high radon concentrations.

In 2008, the Agency recommended that basic radon protective measures be installed in all new UK dwellings ².

The Health Protection Agency's Chief Executive, Justin McCracken, said: "Our Advisory Group's report is a valuable contribution to the growing scientific understanding of the health risks from radon in the home and as a result of the points they have raised we have today published a consultation document which considers all their recommendations. Once the consultation is completed, the Agency will present its recommendations to Government."

AGIR Report: Radon and Public Health.  Report of the Independent Advisory Group on Ionising Radiation.  Docs HPA 2009 http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoListNameDesc/Page/1199451989432?p=1199451989432

Health Protection Agency Consultation Document: HPA Advice to the Limitation of Human Exposure to Radon http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/Page/1204542909765?p=1204542909765

Press enquiries. Contact the CRCE Press Office at Chilton on 01235 822876/ 822745 or e mail chilton.pressoffice@hpa.org.uk

1 Because the risk from radon is proportional to the underlying risk of lung cancer, the great majority of deaths due to radon occur in smokers or ex-smokers.
2 The Board of the Health Protection Agency gave advice on radon protection measures in new homes on 21 May 2008. See Press releases at www.hpa.org.uk

Notes for Editors

• The Advisory Group has reviewed the risk of lung cancer from exposure to radon using epidemiological studies of residential exposures, up-to-date information from epidemiological studies of miners, calculations of radiation dose to different tissues, and laboratory studies on animals.  The data from all these sources is interpreted in the light of the general understanding of the biological, chemical and physical events that take place when ionising radiation interacts with the cellular components of the human body.
• In May 2008, the Board of the Health Protection Agency, having considered a paper from its Radiation Protection Division, recommended to Government that UK Building Regulations and Standards should be changed to ensure that all new property incorporates the basic materials and measures necessary to reduce indoor radon concentrations. This would also apply to new extensions and to any other changes to property where the Building Regulations and Standards apply.
• The Health Protection Agency recommendation for existing homes is that people living in areas where 1% or more of homes are above the current Action Level of 200 Bq m^–3 should measure the radon concentration in their home. If the concentration is found to be above the Action Level, householders are advised to install remedial measures. The government policy in England consists of targeting areas of the country where 5% or more of homes are above the Action Level, offering free radon measurements, and then encouraging householders to remediate at their own expense if the measurement is above the current Action Level of 200 Bq m^–3.
• Radon is a naturally occurring radioactive gas that seeps from the ground into all buildings to some extent.  Concentrations of radon inside buildings depend on a number of factors, including the local geology, the type of foundation, the positioning of service pipe work and internal ventilation levels.
• The Health Protection Agency currently recommends homeowners take steps to reduce indoor concentrations of radon when it is found to be above the radon Action Level, 200 becquerels per cubic metre. Radon preventative measures are required in new buildings in high radon areas.
• The government currently funds surveys of existing homes in defined high-radon areas of the country, which identify homes above the radon Action Level and encourage remediation of them. Such surveys would be more cost effective if the Action Level was 100 Bq m^–3 instead of 200 Bq  m^–3, since the costs of the surveys would be the same in either case, but if the Action Level was reduced, more homes would be remediated.
• The UK was one of the first countries in the world to introduce a radon control policy in 1987 by the then National Radiological Protection Board (now part of the Agency). The advice was revised in 1990. On the basis of limited evidence of the risk of lung cancer associated with radon at the time, the guidance suggested remediation of existing homes with high radon concentrations and preventative measures for new homes in some parts of the country.
  

Last reviewed: 2 June 2009