What is radon?
Radon is a gas that has no colour, odour or taste and comes from the natural radioactive breakdown of uranium in the ground.
You can be exposed to radon by two main sources:
- Radon in the air.
- Radon in private water supplies.
Radon can get into the air you breathe and into the water you drink. Radon is also found in small quantities in outdoor air.
Most of the radon in indoor air comes from soil underneath properties. As uranium breaks down, radon gas forms and seeps into the property. Radon from soil can get into any type of building – homes, workplaces and schools and build up to high levels in the air inside the building.
Radon gas can also dissolve and accumulate in water from underground sources (called ground water), such as wells, springs or boreholes. When water that contains radon is used for showering, washing dishes and cooking, radon gas escapes from the water and goes into the air.
It is similar to carbonated soda drinks where carbon dioxide is dissolved in the drink and is released when you open the bottle. Some radon also stays in the water.
Radon is not a concern in water that comes from lakes, rivers and reservoirs (called surface water), because the radon is released into the air before it ever arrives at your tap.
Why is radon a health concern?
Breathing radon in indoor air can cause lung cancer. Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe it. As they break down further, these particles release small bursts of energy. This can damage lung tissue and increase your chances of developing lung cancer over the course of your lifetime. People who smoke have an even greater risk. Not everyone exposed to high levels of radon will develop lung cancer. However, radon in indoor air is the second leading cause of lung cancer. About 2,500 deaths a year in the United Kingdom are caused by breathing radon in indoor air.
Only about 1 to 2% of radon in the air comes from drinking water. However, breathing radon released to air from tap water increases the risk of lung cancer over the course of your lifetime. Some radon stays in the water; drinking water containing radon also presents a risk of developing internal organ cancers, primarily stomach cancer. However, this risk is smaller than the risk of developing lung cancer from radon released to air from tap water.
Is there radon in my drinking water?
Not all drinking water contains radon. If your drinking water comes from a surface water source such as a river, lake or reservoir, most radon that might be in the water will be released into the air before reaching your water supplier or property. Radon is only a concern if your drinking water comes from underground, though not all water from underground sources contains radon.
I receive water from South West Water. Is there a problem?
There is no problem with radon in mains water supplied by South West Water. Nearly all South West Water’s water sources are upland surface water catchments and the few underground sources in use are regularly checked. No radon enters the mains distribution system.
What levels of radon in indoor air should I be concerned about?
The Government’s recommended action level for radon in air in domestic houses is 200 becquerels per cubic metre. This is the level at which it is suggested you ought to take some remediation action. For recorded levels of Radon within your postcode area.
In workplaces, employers have a duty to comply with the Ionising Radiation Regulations 1999 and here the compliance level is compulsory and fixed at 400 becquerels per cubic metre.
What levels of radon in drinking water should I be concerned about?
There is currently no UK or European Union standard for radon in drinking water. However, the European Union is considering a draft recommendation of the protection of the public against exposure to radon in water supplies. Because the way in which radon irradiates the body is quite different when it is swallowed in water than if it is inhaled in air, the action level for radon in water is not the same as for radon in air. It has been set so that the risk to a typical person drinking water with radon at this concentration is similar to the risk which would arise from breathing air which contained radon at the action level in homes of 200 becquerels per cubic metre.
The European Union draft recommendation is:
- For private water supplies that are part of a commercial or public activity (eg hotels or bed & breakfast) remedial action should always be taken when the radon concentration exceeds an action level of 1,000 becquerels per litre.
- For individual water supplies (no commercial or public activity) consideration should be given to taking remedial action when the radon concentration exceeds an action level of 1,000 becquerels per litre.
These levels have been adopted locally in the South West to deal with radon levels in water which have come to light following a pilot study in West Devon.
How do I test for radon?
Because radon in indoor air is the larger health concern, South Hams District Council recommend that you first test the air in your home for radon before testing for radon in your drinking water.
New homes built in the South Hams area since 1992 should be built radon resistant and have already had radon barriers installed as part of the construction process. However, following a recent survey it has been found that new homes can have elevated radon concentrations
South Hams District Council recommends you take action to reduce your home’s indoor radon levels if your radon test result is 200 becquerels per cubic metre or higher.
Advice on testing for radon can be found in the publication "Radon – You Can Test for It" published by the Department of the Environment, Transport and the Regions and available from South Hams District Council.
How do I test for radon in water?
If you obtain your water from South West Water, there is no need for a test to be carried out – the water will be free of radon.
If your water comes from a private surface water source, most radon that may be in the water will be released to the air before it makes its way to your tap and there is no need to test for radon. If your private water supply source comes from a ground water source, ie a borehole, well or spring, then you may need to have your supply tested.
The analysis of radon and uranium, when undertaken as part of further sampling, costs a further £85.00
How do I remove radon from the air in my home?
There are a number of ways of reducing radon in air, most of them simple and relatively inexpensive. The short guide "Radon – a Guide to Reducing Levels in your Home" published by the Department of the Environment, Transport and the Regions is available from South Hams District Council, contains the relevant information.
How do I treat radon in drinking water?
If testing your private water supply shows that you have high levels of radon in your drinking water and you are concerned about it, there are a number of things you can do to improve the water. The most effective treatment you can apply is to remove radon from the water before it enters your home. This is called point of entry treatment. There are two types of point of entry devices that remove radon from water.
- Granular activated carbon (gac) filters which use activated carbon to remove the radon and;
- aeration devices which bubble air through the water and carry radon gas out into the atmosphere through an exhaust.
GAC filters tend to cost less than aeration devices, however, radioactivity collects on the filter which may cause a handling hazard and require special disposal methods for the filter.
How do I get more information about radon?
Contact South Hams District Council’s Environmental Health Section : 01803 861234
Further Information
