Website of the Department of Health

Radon gas

Indoor radon exposure is the single largest contributor to the radiation exposure of the UK population and is the most common cause of cancer from ionising radiation in the UK. Radon is the second most common cause of lung cancer in the UK after smoking. Radon is a colourless, odourless, radioactive gas that originates from natural uranium, which occurs in trace amounts in virtually all rocks and soils. Radon accumulates in buildings and levels can vary because the concentration depends on many factors including the underlying geology, building construction and lifestyle of the occupants.

Radon is thought to cause about 100 lung cancer deaths in non-smokers every year. Up to 2000 smokers and ex-smokers die each year because of exposure to radon who would not have died from smoking alone. It has been known for many years, originally from epidemiological studies on miners, but confirmed more recently from domestic studies, that high radon concentrations cause lung cancer.

The radon programme for England is currently based on a ‘find and fix’ strategy for homes above the UK Action Level by targeting measurements in higher risk areas and advising on remediation. The objective of the programme is to identify and reduce the high radiation doses received by individuals   However, with only a small percentage of houses being above the Action Level, the major burden of radon-attributable deaths are estimated to occur at much lower levels. To address these deaths it is necessary to reduce the general exposure of the population and this is the target of the recent advice from the Health Protection Agency (May 2008) on the desirability of incorporating radon protective measures in all new buildings.

Government radon policy responsibilities

In England, improvement of building regulation standards (for new buildings, extensions, conversions or refurbishments) rests with the Department for Communities and Local Government (DCLG), workplace issues, including schools rest with the Health and Safety Executive (HSE) but the school building policy issues rest with the Department for Children, Schools and Families (DCSF). The Department of Health (DH) leads on the Health Protection issues and acts as the central focus for other departments on radon gas.

On 1 April 2005, responsibility for the domestic radon roll-out programme in England was passed from the Department of Environment, Food and Rural Affairs (DEFRA) through DH to the Radiation Protection Division of the Health Protection Agency (HPA-RPD), with an annual ring-fenced funding.  This funding covers the find and fix programme, the new website and funding for the remediation of extremely high homes.  Devolved Administrations generally mirror English policies and contribute similar proportionate funds to HPA for each initiative.

The ‘find and fix’ programme

The basis of the radon programme in England for existing homes is to target the higher risk areas, where 5 per cent or more of the houses are estimated to be above the Action Level. Radon testing programmes are run in partnership with local authorities, with radon tests funded by HPA (free to the householder) and with considerable input from the primary care trust and the Building Research Establishment (BRE).

Registered social landlords such as local councils and housing associations are also involved and encouraged to extend the radon testing programmes to all their properties in Radon Affected Areas (that is where 1 per cent or more of homes are estimated to be above the Action Level). HPA-RPD informs householders or landlords by letter of the result of the radon test and whether it is near to or exceeds the Action Level. If so, remediation is advised and the householders are encouraged to attend special events to discuss remediation organised jointly by the HPA-RPD, the relevant local authority and BRE.

Measurements in workplaces (including schools) are paid for by employers or local authority. HPA-RPD has been asked to send all schools in Radon Affected Areas an advisory pack explaining the risks and how to obtain measurement support.  HSE and DCSF are fully supporting this initiative.

Higher-risk areas are indicated by recently improved maps produced jointly by HPA-RPD and the British Geological Survey, which use both geological and known local radon measurement data.  HPA uses the measurement datasets to inform users who contact them when they consider the map shows that their property may be at risk.

• UKradon website (opens new window)

Radon risk communication

Radon is not generally considered a hazard by the public, despite it being responsible for about half of the average annual ionising radiation exposure in the UK.  The new website and the schools programme aim to improve public understanding of the hazard caused by radon and raise the profile of the radon programme