HPA Advice on the Limitation of Human Exposures to Radon

Author(s):

HPA Radiation Protection Division

Summary:

HPA is considering revising its advice on limiting the exposure of the population to unduly high levels of radon and its short-lived decay products in buildings. This consultative document describes the suggested new advice which would replace the advice published in 1990 by the National Radiological Protection Board (which joined the Health Protection Agency in April 2005). There are six main reasons for going out for consultation on this topic now. First, there are new epidemiological data confirming the link between exposure to radon in the home and an increased risk of lung cancer. Second, since 1990 an increasing body of experience has been gained on remediation of radon in homes. Third, costeffectiveness analysis by the Advisory Group on Ionising Radiation (AGIR) suggests that a reduction in the radon Action Level could be cost-effective. Fourth, the analysis carried out by AGIR indicates that the majority of radon-related lung cancer deaths occur amongst the large percentage of the population exposed to modest radon levels. Fifth, international organisations such as WHO, ICRP, EU and IAEA have recently issued or are developing revised advice on radon. Sixth, there is increasing concern about the health risks from radon at UK Government level and in expert groups such as the Committee on the Medical Aspects of Radiation Exposure (COMARE).

The advice is mainly concerned about exposures of the public wherever they are and is intended to reduce the radiation exposure of those most at risk from high levels of radon and to lead over time to a reduction in the average exposure of the whole population to radon. The latter aim follows from the recognition that most radon-induced lung cancers occur among the main body of the population exposed to low or moderate levels of radon rather than the small proportion exposed to high levels. It should be noted that advice on the desirability of installing basic radon preventative measures in all new buildings, extensions, conversion and refurbishments and on testing the effectiveness of full preventative measures within one year of occupation has already been provided to Government by HPA. This Consultation mainly concerns the radon preventative measures in existing buildings: outdoors, long-term radon levels are low.

The key points for consultation include:

Whether the present system of a domestic radon Action Level of 200 Bq m^-3 and a threshold for radon Affected Areas where 1% of homes are estimated to be above the Action Level should be changed. Two alternatives are considered: a reduction of the Action Level to 100 Bq m^-3, with Affected Areas being defined as those estimated to have 5% or more of homes above the new Action Level, or a system in which the radon Action Level is 100 Bq m^-3, and areas of the country are defined as low, medium or high risk on the basis of the percentage of homes estimated to be above the new Action Level.

Whether the domestic radon Action Level should apply to buildings, such as schools and care homes, where members of the public could be exposed to radon for prolonged periods, as well as to dwellings.

Seven questions are posed in the document.

This consultation closed on 3 September 2009. The HPA will publish the outcome in due course. The consultation document remains available.

PDF download:

Hard copies will not be made available.

HPA Advice on the Limitation of Human Exposures to Radon (PDF, 150 KB)

Last reviewed: 26 January 2010