What is radon gas?
Radon forms during the natural decay of uranium in the ground. It has no colour or smell, so sight and smell cannot establish whether indoor levels are elevated. A radon detector measures what people cannot sense directly.
For Radon Map Check's UK audience, the practical distinction is between the presence of radon and its concentration. The gas occurs naturally; a suitable test is needed to assess a particular building.
Source: UKradon: what is radon?
How does radon enter buildings?
Radon from the ground can enter through gaps and openings in a building's lower structure. Indoor concentration depends on both the ground and the building, including ventilation. Different buildings in the same area may therefore give different results.
Radon Map Check's postcode walkthrough cannot model these building conditions. Ground-floor, basement and underground spaces require appropriate consideration under official guidance.
Sources: UKradon maps and limitations; radon reduction methods.
Why does indoor radon matter?
Exposure to radon increases the risk of lung cancer. Smoking and radon exposure together increase the risk further. A postcode or a map colour cannot diagnose illness or quantify an individual's medical risk.
Use UKradon's health-risk guidance for the public-health context. Discuss personal health concerns with a qualified health professional. Radon Map Check provides educational information, not medical advice.
Should I use a map or a test?
Use both for their different purposes: a map helps identify area potential, while a test provides evidence about indoor radon. A lower-potential area does not rule out an elevated result in an individual home.
- Start with the official UK map or address-search service.
- Follow home-testing guidance where appropriate.
- Use the test provider's report and Action Level guidance to choose the next step.
Does this guidance cover Scotland?
The UK-focused explanations apply to the distinction between mapping and measurement. Use UKradon's current mapping and relevant national guidance for a Scottish property. Radon Map Check does not publish a Scotland-specific postcode dataset or a separate Ireland service.
Common radon questions
Can a smoke or carbon monoxide alarm detect radon?
No. Radon testing requires a detector designed for radon. Check the intended use of any device and follow official measurement guidance.
Can I tell the level from how my house feels?
No. Radon cannot be seen or smelled. Use a suitable measurement, rather than symptoms or how a room feels, to establish an indoor radon result.