In December 2022, the UK Health Security Agency (UKHSA) and British Geological Survey (BGS) published the first update to the UK radon risk maps in over 10 years.
The colour-coded maps show the likelihood of a building containing elevated levels of radon and are the product of years of new analysis and research, combining geological mapping with UKHSA’s database of in-home radon monitoring results.
There is a free-to-access interactive map available at www.ukradon.org, which is searchable by postcode and will indicate the predicted level of risk for any given UK address. This map is based on the worst case scenario for each 1km grid square of the UK, with a more precise result available for a small fee.
The colour scheme of the maps has also been updated, with all areas now shaded from cream to dark brown, with the darker the colour the greater the probability of finding high radon levels.
propertECO have carried out some informal analysis of the maps, comparing the previous version to the new to see how the risk estimates have changed in different parts of the country, and the impact overall.
By re-checking the radon risk band status for just under 1000 addresses for a national client, we determined that within this sample, 13% of addresses had moved from a <1% risk area (where testing is not required) to an area deemed to be a radon Affected Area (1-3% risk or greater). Conversely only 2% of properties were previously located within Affected Areas and had now been downgraded to <1% risk. We found that 5% of properties in Affected Areas had moved up at least one risk band, and that 2% had moved down, but still remained in an Affected Area. Overall, there was no change in risk classification for 78% of the addresses.
We noted that there had been significant shifts in the risk estimates in certain parts of the country. For example in certain parts of Kent the previous maps estimated a 1-3% probability of finding high levels of radon but the new maps have increased this to greater than 30% probability. Similarly, areas to the East and West of Leeds that were previously classified as having less than 1% probability have now increased to 5-10% probability, whilst the probability in the city centre itself has increased from 1-3% to 3-5%.
It is important to note that the actual risk from radon in these areas is not new; radon has always been produced in the ground and will continue to be emitted long after our lifetimes. What has changed is our knowledge on the geologies most likely to give rise to elevated radon concentrations in buildings, and the mapping technologies available to present this into a meaningful format.
The message ‘to test is best’ has always been promoted within the radon industry as no matter how sophisticated the mapping becomes, it remains based upon predictions and probability, rather than being able to provide a definitive answer as to whether any given building will be affected by harmful levels of radon. To measure the radon concentration in any given building, a radon test must be completed.
If you’d like to discuss how the updated map affects your home or business, please get in touch and we’d be happy to offer our advice.
