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Home News centre National Press Releases 2010 Press Releases ›  HPA issues new advice on radon

HPA issues new advice on radon

8 July 2010

A new initiative to reduce concentrations of radon in UK homes has been launched by the Health Protection Agency.

Radon, a naturally occurring radioactive gas, is the biggest source of human exposure to ionising radiation in the UK and is responsible for an estimated 1,100 lung cancer deaths a year.

After reviewing the latest scientific evidence, as well as the costs and benefits of radon reduction measures, the HPA is retaining its Action Level of 200 becquerels per cubic metre (Bq m-3) – but introducing a new Target Level of 100 Bq m-3.

The Target Level has been introduced because research published since 1990 has given scientists a greater understanding of the risks to health of exposure to radon below 200 Bq m-3 and because HPA now has considerably more experience of the effectiveness of remediation measures.  Although low level exposures can still lead to lung cancer, the risks at these levels are low and can be reduced further by simple mitigation measures designed to increase underfloor ventilation.

Dr John Cooper, director of the HPA’s Centre for Radiation, Chemicals and Environmental Hazards, said: “We are retaining the Action Level of 200 Bq m-3 so that our efforts can be firmly focussed on those at greatest risk. However the new Target Level of 100 Bq m-3 will enable us to ensure people are aware that even below 200 Bq m-3 there are still risks to health and simple remediation measures can be taken to reduce these.

“The HPA recommends that people in homes where radon levels have been recorded between the two figures should think carefully about preventative action to protect their health.

“Together with our previous recommendations to Government on the inclusion of basic radon protective measures in all new buildings, the new advice is an appropriate practical response based on good scientific evidence of the risks of lung cancer from radon exposure.”

The HPA recommends that Target and Action Levels should be applied to other premises where occupancy by members of the public exceeds 2,000 hours per year and to all schools.

Radon measurement programmes are organised on the basis of predictions of the probability that homes and other buildings in different parts of the country will have radon concentrations exceeding the Action Level.

Householders can find out the likelihood that their home is above the Action Level at The HPA report: HPA Advice on the Limitation of Human Exposure to Radon, can be viewed here

To view indicative radon maps for England, Wales, Scotland and Northern Ireland, go to

For further information please contact the CRCE Press Office on 01235 822737/876/745.

Notes to editors

  • The new HPA report also recommends keeping the current system of designating Radon Affected Areas as those with a 1% or greater chance of exceeding the Action Level. Parts of the country with less than a 1% chance of exceeding the Action Level will now be referred to as Lower probability areas; the terms Intermediate and Higher probability will be applied to areas with 1 – 10% chance and at least a 10% chance of exceeding the Action Level. HPA recommends that householders in intermediate and higher probability radon areas should have measurements made of indoor radon concentration in their home.
  • The recommendations follow recent advice and improved evidence on the risks from radon issued by the International Commission on Radiological Protection (ICRP) and the World Health Organisation (WHO). The HPA’s independent Advisory Group on Ionising Radiation (AGIR) also recently issued recommendations about radon and public health and the HPA (NRPB prior to 2005) has published radon probability maps of all parts of the UK.
  • In May 2008, the Board of the Health Protection Agency recommended to Government that UK Building Regulations and Standards should be changed to ensure that all new property incorporates 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.
  • 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.
  • Radon preventative measures are currently required in new buildings in areas with elevated radon levels.
  • 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: 7 July 2010