Radon is a natural radioactive gas. You cannot see, hear, feel or taste it. It comes from the minute amounts of uranium that occur naturally in all rocks and soils. Radon is present in all parts of the UK, although the gas disperses outdoors so levels are generally very low.
We all breathe it in throughout our lives - for most UK residents, radon accounts for half of their total annual radiation dosage.
However, geological conditions in certain areas can lead to higher than average levels. Some of the highest radon levels have been found in the southwest, but levels well above average have been found in some other parts of the UK. Exposure to particularly high levels of radon may increase the risk of developing lung cancer.
The HPA has advised that indoor radon above an Action Level of 200 becquerels per cubic metre (Bq m-3) should be reduced. Most homes in the UK have fairly low radon levels, with an average of about 20 Bq m-3. The HPA conducts radon surveys for government departments, local councils, other organisations, and private householders.
Small radon detectors can be sent directly to householders by post, and returned at the end of a three month period. Radon causes invisible damage to the plastic inside the detector. This damage can be measured and used to calculate the radon level. The householder is sent the result by letter.
The most effective way to deal with radon is to fit a 'radon sump' to a property to vent the gas into the atmosphere. A sump has a pipe connecting a space under a solid floor to the outside. A small electric fan in the pipe continually sucks the radon from under the house and expels it harmlessly to the atmosphere. Modern sumps are often constructed from outside the house so there is no disruption inside.
For more information about radon, the risks it presents and how you can protect your home, see the list of frequently asked questions.
The HPA also produces a free radon information pack which gives basic information about radon and describes how to obtain a radon measurement.
To request a pack, please email your name, address and postcode to firstname.lastname@example.org or leave your name, address and postcode on the HPA free radon answerphone (0800 614529).
Information is also available about radon in the workplace.