Dealing with radon emissions in respect of new development : evaluation of mapping and site investigation methods for targeting areas where new development may require radon protective measures

摘要

Radon gas comes from uranium that occurs naturally in the ground. The variation in radon levels betweenuddifferent parts of the country is mainly controlled by the underlying geology. Radon decays to formudradioactive particles that can enter the body by inhalation. Inhalation of the short-lived decay products ofudradon has been linked to an increase in the risk of developing cancers of the respiratory tract, especially of theudlungs, and is considered to cause approximately 5% of deaths from lung cancer in the UK. In order to limitudthe risk to individuals, the Government has adopted an Action Level for radon in dwellings of 200 becquerelsudper cubic metre (Bq m-3). The Government advises householders that, where the radon level exceeds theudAction Level, measures should be taken to reduce the concentration.udIn the early 1990s, administrative and policy responses to radon problems in new development had limitations inudthat:ud− new development was not adequately covered by existing responses in radon-prone areas which had not beenuddesignated as radon Affected Areas.ud− the mapping procedures used to identify those areas where protective measures were required in newuddwellings in some cases resulted in radon protection not being installed where required, and vice versa.ud− they did not adequately cover material change of use or non-domestic development, including workplacesudand certain residential institutions.ud− procedures were not in place to ensure that developers were made aware of requirements for protectiveudmeasures in new dwellings or of employers' responsibilities with regard to radon under the Health and Safety atudWork etc. Act 1974 and Ionising Radiations Regulations 1985 at the planning or pre-planning stage.ud− developers and future occupiers of buildings subject to material change of use (for example fromudagricultural or workplace to domestic use (e.g. barn conversions)) but not subject to Requirement C2 ofudSchedule 1 of Building Regulations 1991 were not necessarily made aware of the possible need forudprotective or remedial measures.udThese limitations have been addressed by the Department of the Environment, Transport and the Regionsud(DETR) research programme ‘Dealing with radon emissions in respect of new development’ which aimed toudidentify the circumstances, if any, where new development may be adversely affected by radon emissions and theudappropriate response to such problems. Fulfilment of these objectives will help to ensure that occupiers of newuddomestic and non-domestic developments will be adequately protected against the harmful affects of radon.udThe research programme, carried out by the British Geological Survey (BGS) working in collaboration with theudBuilding Research Establishment Ltd. (BRE), Land Use Consultants (LUC) and the National RadiologicaludProtection Board (NRPB).udThe report Dealing with radon emissions in new development: Summary report and recommended framework for planningudguidance (Appleton et al., 2000) explains the background to dealing with radon in new development. Itudhighlights where improvements to the responses could be made and identifies the available options for dealingudwith radon in new development, including their relative advantages and disadvantages. The report alsoudidentifies the potential role of the planning system and presents conclusions and recommendations on whichudoption(s) would be most appropriate and effective for ensuring that new development is protected againstudradon emissions.udThis report summarises an evaluation of mapping and site investigation methods currently available forudtargeting areas where new development may require radon protection. The report also describes the systemudadopted in revised guidance (BR211, 1999) to determine the level of protection needed in new dwellings anduddiscusses mapping and site investigation costs.