Radon

What is Radon ?

Radon is a colourless, odourless radioactive gas. It comes from the radioactive decay of radium, which in turn comes from the radioactive decay of uranium which is found in small quantities in all soils and rocks, although the amount varies from place to place. It is particularly prevalent in granite and limestone areas but not exclusively so. Radon levels vary not only between different parts of the country but even between neighbouring buildings.

Radon in the soil and rocks mixes with air and rises to the surface where it is quickly diluted in the atmosphere. Concentrations in the open air are very low. However radon that enters enclosed spaces, such as buildings, can reach relatively high concentrations in some circumstances.

What is the Problem ?

When radon decays it forms tiny radioactive particles which may be breathed into the lungs. Radiation from these particles can cause lung cancer which may take many years to develop. In addition, smoking and exposure to radon are known to work together to greatly increase the risk of developing lung cancer.

How Does Radon Enter a Building ?

The floors and walls of dwellings contain many small cracks and gaps formed during and after construction. Radon from the ground is drawn into the building through these cracks and gaps because the atmospheric pressure inside the building is usually slightly lower than the pressure in the underlying soil. This small pressure difference is caused by the stack (or chimney) effect of heat in the building and by the effects of wind.

Where is Radon a Problem ?

The principal areas of the country in which radon is a problem are the granite areas of Cornwall and Devon, and the limestone areas of Derbyshire, Northamptonshire, North Oxfordshire, Lincolnshire, and Somerset, however there are many other areas in England and Wales affected by radon. 

When is Radon a Problem ?

For the purpose of considering risk in the home the Health Protection Agency Radon Protection Division formerly the National Radiological Protection Board has advised the Government that the level of 200 Bq/m3 should be considered the Action Level. If the radon level in your home is close to or above the Action Level you should take action to reduce the level, ideally to well below the action level.

How can you Protect against Radon ?

Further information can be found using guidance set out in BRE's Guidance Booklet.

* Contact Melton Building Control for further advice.