ARCHIVE: e-Digest Statistics about: Radioactivity
Figure 4 Radon Affected Areas in Northern Ireland
Radon-222 (222Rn) is a naturally occurring radioactive gas which comes out of the ground. In the open air, it is dispersed but it can accumulate in buildings. The gas decays into minute solid particles which, if breathed in, can be deposited on the surface of the lungs and increase the risk of lung cancer. Of the 34,000 UK deaths from lung cancer each year, around 5 per cent are attributable to radon, which is believed to be the second most important cause of the disease after smoking. A fuller account is given in a report published by NRPB in 2000 .
A national survey  by NRPB was published in 1988 and found the average indoor concentration of radon gas to be 20 Bq/m³. This level of radon, taken together with exposure elsewhere, leads to an average annual dose of 1.3 mSv. However, very much higher levels are found in some areas and, in 1990, the Government of the day accepted advice that any householder with radon concentrations above 200 Bq/m³ (the Action Level) should take remedial action to reduce radon levels in their homes . A measurement programme was started in 1987 to identify homes above the Action Level.
The first radon Affected Area was identified in Cornwall and Devon in 1990. Further Affected Areas were identified in Derbyshire, Northamptonshire and Somerset in 1992, in parts of Highland and Aberdeenshire in Scotland and the south-east corner of Northern Ireland in 1993, and in some parts of Wales in 1996. Also in 1996, radon Affected Areas in the remainder of England were identified  and a radon atlas of England was published . The atlas is based on 5 km squares of the Ordnance Survey National Grid and shows also major towns and administrative boundaries. The figure 2 'Radon Affected Areas in England' shows the estimated proportion of homes exceeding the Action Level in each 5 km grid square in England. The shaded areas of the figure are defined as radon Affected Areas.
A report for England, was published in early 1997 , summarising the results from some 300,000 measurements completed in England by the end of 1996, presented at county, local authority and postcode district level. NRPB published maps and results for Wales in 1998  and Northern Ireland in 1999 . In 2002, a new report was published bringing together and updating information on radon levels measured in homes in England and Wales . These are summarised by county and unitary authority for England in the table 'Radon results by metropolitan and rural county and by unitary authority'. The table 'Radon results by unitary authority' summarises results for Wales by unitary authority. Results for Northern Ireland are summarised by district council in the table 'Radon results by county or metropolitan area' . Figures 5 and 4 show the estimated proportion of homes exceeding the Action Level in each 5 km grid square in England and Wales and in Northern Ireland. The shaded areas of the figure are defined as radon Affected Areas. Key Fact shows the mean radon levels throughout the United Kingdom, as a whole.
- References, further reading and links to other resources:
-  Hughes, J S, National Radiological Protection Board (1999). Ionising Radiation Exposure of the UK Population: 1999 Review, NRPB-R311. TSO.
-  The Ionising Radiations Regulations 1999, Statutory Instrument 1999 No 3232. TSO.
-  National Radiological Protection Board, Faculty of Public Health Medicine, Chartered Institute of Environmental Health (2000). Health Risks from Radon..
-  Wrixon, A D, National Radiological Protection Board (1988). Natural Radiation Exposure in UK Dwellings, NRPB-R190. TSO.
-  National Radiological Protection Board (1990). Board Statement on Radon in Homes, Doc NRPB 1, No 1. TSO.
-  National Radiological Protection Board (1996). Radon Affected Areas: England and Wales, Doc NRPB 7, No 2.
-  Lomas, P R, National Radiological Protection Board (1996). Radon Atlas of England,. NRPB-R290. TSO.
-  Bradley, E J, National Radiological Protection Board (1997). Radon in dwellings in England: 1997 Review, NRPB-R293. TSO.
-  Lomas P R, National Radiological Protection Board (1998). Radon in dwellings in Wales: atlas and 1998 Review, NRPB-R303. TSO.
-  Green B M R, National Radiological Protection Board (1999). Radon in dwellings in Northern Ireland: atlas and 1998 Review, NRPB-R308. TSO.
-  Green, B M R National Radiological Protection Board (2002) Radon Atlas of England and Wales NRPB-W26
- Figure 5 Source: National Radiological Protection Board, This map has been published in the booklet "Health Risks from Radon".
- Internet Links:
- Frequently asked questions and answers relating to radon and buildings:
- Building Research Establishment Ltd (BRE) Radon help line: 01923 664707
- Background information
- Department for Environment Food and Rural Affairs (Defra): Radon
- National Radiological Protection Board (NRPB)
- National Radiological Protection Board
- http://www.hpa.org.uk/radiation/radon/index.htm This map is based on maps published in the Radon Atlas of England and Wales (NRPB-W26).
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Page last modified: 16 September 2003
Page published: 10 September 2003