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Check if your Property or Building may be Affected By Radon Gas

Across the UK, there are several regions of the country affected by radon gas.

Type your location by town or postcode into the search bar below and click ‘Show Radon Data’

The information is from the interactive map from, the radon website based on data from UK Health Security Agency (formerly PHE).

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Radon gas is measured in preferred radon level measurement unit (Becquerels per cubic meter, Bq/m3.) UK Health Security Agency (UKHSA). (formerly PHE) has published this map (to the right) showing where high levels are more likely.

The darker the colour the greater the chance of a higher level. The chance is less than one home in a hundred in the white areas and greater than one in three in the darkest areas.

UK map of radon gas

Every building contains radon but the levels are usually low. The chances of a higher level depend on the type of ground. UK Health Security Agency (UKHSA). (formerly PHE) has published a map showing where high levels are more likely. The darker the colour the greater the chance of a higher level. The chance is less than one home in a hundred in the white areas and greater than one in three in the darkest areas.


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Radon - risks to your health

You can visit their website and enter your postcode to establish your risk. The risks to your health from radon: High levels of radon can cause lung cancer, particularly for smokers and ex-smokers. Radon produces tiny radioactive particles in the air we breathe. Radiation from these particles damages our lung tissue, and over a long period may cause lung cancer.


The higher the level and the longer the period of exposure, the greater the risk will be.


Radon Action Level and Target Level

Indoor radon often varies from building to building within the same area. The Target Level (100 bqm3) and Action Level (200 bqm3) are important averages in assessing concentrations and ideal outcomes.


How to reduce radon levels: The ground is the main source of radon. The aim of our remedial work is to reduce radon levels in your home as low as possible. There are several methods that can reduce high radon levels in homes such as installing a radon sump or introducing positive pressure (PIV unit).


What is Radon?
Radon is a naturally occurring gas. It is a colourless, odourless radioactive gas and is formed by the radioactive decay of the small amounts of uranium that occur naturally in all rocks and soils and can be found in our homes.

Radon Gas poses a risk to health and Radon Protection UK provides protection to both new and existing buildings.

Where will we find Radon?
Radon is everywhere; formed from the uranium in all rocks and soils. Outdoors everywhere and indoors in many areas the radon levels are low and the risk to health is small. The darker the colour on the radon maps, the greater the chance of a high radon level in a building. However not all buildings, even in the darkest areas, have high levels. These maps produced by UKHSA give an indication of the areas that are more likely to see increased levels in radon but the only way to be sure, is to test.

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Radon gas image

How does Radon effect our health?
Radon produces a radioactive dust in the air we breathe and radioactive elements decay and emit radiation. The radioactive elements formed by the decay of radon can be inhaled and enter our lungs. Inside the lungs, these elements continue to decay and emit radiation, most importantly alpha particles. The dust is trapped in our air ways and these are absorbed by the nearby lung tissues and cause localised damage. Testing is the only way to be sure of accurate radon levels within a property.

The evidence Radon is harmful:
Studies in many countries have shown that increased exposure to radon increases your risk of lung cancer. In the UK 1100 deaths occur each year from lung cancer that has been causes by radon. It is now widely accepted that radon gas exposure is the second highest cause of Lung cancer after smoking.

What is our exposure to radiation?
We are all exposed to radiation from natural and man-made sources. Just 20 Bq m-3 (the average radon level in UK homes) gives us half our exposure to radiation from all sources. Higher radon levels give higher exposures: that is why it is important to find out the levels in your home and carry out a radon test

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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.

How is Radon measured?

The amount of radon is measured in becquerels per cubic metre of air (Bq m-3). The average level in UK homes is 20 Bq m-3. For levels below 100 Bq m-3, your individual risk remains relatively low and not a cause for concern. However, the risk increases as the radon level increases.

How does radon enter a building
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radon symbol

What is the Radon Action level In The Home?
UK Health Security Agency (UKHSA). (formerly PHE) recommends that Radon levels should be reduced in homes where the average is more than 200 becquerels per metre cubed (200 Bq m-3). This recommendation has been endorsed by the Government. This Action Level refers to the annual average concentration in a home. Therefore, on a typical domestic property, radon measurements are carried out with two detectors (One in a bedroom and one in the living room). Measurements are monitored over three months to average out short-term fluctuations. Larger homes may require more than two detectors. Although the guidance recommends monitoring over a three month period, there may be instances where a short term test may be necessary perhaps if buying a property. Shorter term tests are also available from Radon Protection UK Shop.

What is the Target Level?
The Target Level of 100 Bq m-3 is the ideal outcome for remediation works in existing buildings and protective measures in new buildings. If the result of a radon assessment is between the Target and Action Levels, action to reduce the level should be seriously considered, especially if there is a smoker or ex-smoker in the home.


If a radon level in any part of a workplace exceeds 300 Becquerels per cubic metre (Bq m-3) as an annual average, the Regulations covering ionising radiations apply. The employer is then obliged to take action. Radon measurement reports from UKHSA include advice to guide employers on the actions they can take to protect staff.

Radon levels can vary over time. This is usually because of changes to the construction of the building or alterations to heating and ventilation which can be caused by a change in use. For this reason, radon should remain in your routine reviews of risk assessments. Consider any changes and assess whether or not the test needs to be repeated. If a radon reduction system has been installed to reduce high levels, those systems may also fail over time and radon levels should be checked annually.

Radon In The Workplace

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