FAQ

Radon is a naturally occurring radioactive gas. It is produced when small amounts of Uranium in rocks and soil break down. You cannot see, smell or taste it, which is why testing matters.

Outdoors, Radon normally disperses and is not much of an issue. Indoors, especially in ground-floor rooms, basements, cellars and poorly ventilated buildings, it can build up.

Yes, it is. Breathing Radon decay products over years can increase the risk of lung cancer. Radon is the second leading cause of lung cancer after smoking, claiming over 1,100 lung cancer deaths each year in the UK. The risk is higher for ex-smokers and significantly higher for current smokers.

Radon usually enters from the ground through tiny gaps and pathways, such as:

• cracks in concrete floors
• gaps around pipes and service entries
• joints between floors and walls
• suspended timber floors
• construction joints
• basements, cellars and rooms partly below ground
• cavities and voids beneath the property

Radon problems are often worse in lower rooms and in winter, when homes are heated and ventilation patterns change. It is also why two neighbouring houses can have different results. Geology matters, but so do foundations, floor type, ventilation, and building alterations.

Radon risk varies heavily by local geology. In the UK, higher-radon areas include much of Cornwall and Devon, as well as parts of Somerset and Dorset. You can use the UK radon map for an address-specific Radon search. Radon Affected Areas are places where there is a 1% chance or more of a home being at or above the UK domestic Action Level of 200 Bq/m³.

For homes, the key numbers are:

Below 100 Bq/m³ – Generally treated as relatively low risk
100 Bq/m³ – UKHSA Target Level, a sensible aim after remediation
200 Bq/m³ – UK Domestic Action Level
Above 200 Bq/m³ – UKHSA recommends reducing the level

For workplaces, the key number is different – 300 Bq/m³ annual average. Ionising Radiations Regulations apply where Radon is above that level, and employers must take action to restrict exposures.

You can easily test for Radon with a Short Term (10 Days) or a Long Term (90 Days) Radon Detector Kit. To find out more, you can read our in-depth blog on Radon Testing.

Yes, especially if the property is in a Radon Affected Area, has a cellar or basement, is built into a slope, or has lower-ground living space. Home surveys are becoming more aware of the risk from Radon. As such, they will now indicate whether the property is in a Radon Affected Area and will ask if a Radon measurement has been conducted.

Regardless of the location, properties with a basement should have a Radon test carried out, as high levels can be found in basements due to their being underground.

If you are using passive detectors for Long Term Measurement, you can measure at any time of year. The results will be seasonally adjusted to provide an estimate of annual concentration. We recommend that the measurement period avoid times when the building is unoccupied or not used to its usual occupancy levels.

You can complete a Short Term Test (typically 10 days) using passive detectors. These will give an indication of Radon levels, but will not give a good estimate of annual average concentration. Radon levels vary by the hour, day and season, so the results from a short-term measurement will very much depend on when you measure. If you measure on a hot summer’s day when the windows are open and heating is off, the results will be very different to a winter measurement when windows are closed and heating may be on.

Yes. A new-build can still have elevated Radon levels, even if protective measures were installed.

New builds in higher-risk areas may require Radon protective measures, such as membranes, barriers, sumps or ventilated sub-floor systems. BRE’s Guidance on protective measures for new buildings covers Radon protective measures for new buildings, extensions, conversions and refurbishments across England, Wales, Scotland, and Northern Ireland.

If you are looking at buying a home, we would recommend asking your legal team about a Radon Bond. This enables a small percentage of the sale price to be held back for a period of time to enable Radon measurements to be made. The funds can also be used for any required remediation.

For private homes, the homeowner is generally responsible for testing and remedial work.

For landlords, Radon can fall under general duties to provide safe accommodation, especially if the property is in a Radon Affected Area or has rooms below ground. Specific obligations can depend on the tenancy type, property use, and any local authority involvement.

For employers, the position is clearer. Under the Management of Health and Safety at Work Regulations 1999, employers must manage Radon as part of health and safety law where it is a hazard. Ionising Radiations Regulations also apply.

Employers who carry out work involving ionising radiation are required to consult a Radiation Protection Advisor, or RPA. Further guidance on when an RPA must be consulted is set out in Schedule 4 of the Ionising Radiations Regulations.

Paul Jarvis is a certified Radiation Protection Advisor and Chartered Radiation Protection Professional with over 20 years’ experience across Health Physics, Radiological Protection, and Nuclear Safety. His career spans nuclear licensed sites, defence, and nuclear power, alongside consultancy work both in the UK and internationally.

At Jarvis Nuclear, we supply passive Radon Testing Kits for both short and long-term monitoring. These are analysed by an accredited laboratory, and once the results are available, we can advise on whether any further action may be required.

For homes and businesses across Cornwall, Devon, Somerset, and Dorset, we can provide guidance on whether radon remediation should be considered. Although we do not carry out remediation work ourselves, we can signpost you to organisations that do.

We also assist businesses and educational settings in these areas with risk assessments where Radon levels exceed the workplace Action Level.

In addition, we can act as Radiation Protection Advisors and provide tailored Radon awareness and Radiation Protection Supervisor training courses to meet your specific needs.

From our base in Plymouth, our Radiation Protection Advisors cover all of Cornwall, Devon, Somerset, and Dorset. If you require any Radiation Protection & Radon Awareness services in these areas, please call us on 07587 167711 or email us by filling in our contact form.

We offer Radiation Protection Supervisor (RPS) training, as well as general Radiation Awareness training. We can provide bespoke courses specific to your niche. All our courses include an assessment, and successful participants are issued an official RPS training certificate. We can also help your organisation in the development and review of RPS portfolios.