What is radon gas?
Radon is a naturally occurring, odourless radioactive gas which is a by-product produced when Uranium, within soil and rocks, decays. Radon is drawn up through the soil and if buildings are present it can be drawn inside them through a process called advection. Advection means where the gas moves from areas of high pressure to lower pressure.
Is radon gas harmful?
There is evidence to suggest that exposure to Radon Gas, over a prolonged period, may be linked to cases of lung cancer, with smokers being at a higher risk. It is likely that many victims were not aware of the risks of Radon and therefore no precautions were taken to protect their home or workplace. However, there are now techniques and products that can be used to prevent build-up of Radon within properties, so risks can be minimised.
Where is it found?
Radon levels are dependent on geographical location as certain rocks contain more uranium than others; igneous granite contains more uranium (10 – 20 parts per million) than other rocks so areas built upon granite are more likely to experience issues with Radon. Public Health England has advised that properties with basements are at risk of exposure to higher Radon levels as there is a higher surface area for the gas to permeate through.
How is radon measured?
Radon levels are measured in “becquerels” per cubic metre of air (Bq-m-3). The average level in UK homes is 20 Bq-m3. For levels below 100 Bq-m3, the overall risk is considered to be low and without need for remedial intervention. There is an action level of 200 Bq-m3 whereby remedial work is likely to be specified, which is likely to centre around improving ventilation and air movement to disperse Radon gases.
Is there radon in my property?
Radon levels are usually higher in basements, cellars and living spaces in contact with the ground. However, considerable radon concentration can also be found above the ground floor. Radon concentrations can vary considerably in areas throughout the country and also, from one building to another adjacent building.
Radon can only be effectively detected over a period of time (usually 3 months, although a shorter 10 day screening period may be applicable) using Radon detectors. The results have to be processed in a Health Protection Agency (HPA) approved laboratory. Where an existing cellar is to be converted into a living area, it is more effective to test levels after the conversion as the types of wall linings used during the conversion process will impact on the levels of Radon drawn into the property. It is also true to say that Radon levels within buildings tend to be significantly higher during the winter months, when buildings are generally less well ventilated.
If you are considering converting your basement then it is important that during the design process, the British Standard for below-ground waterproofing BS8102:2022 is considered, as this standard includes information on protection from Radon, where necessary.
If you are concerned that your property may be affected by Radon then please contact a qualified Surveyor, who can carry out the screening process and make suggestions for remedial work.