Radon Statistics UK: The Definitive Guide (2026)

The Silent Killer: 1,100 Lung Cancer Deaths Every Year

Radon is colourless, odourless, and tasteless. You cannot see it, smell it, or taste it — and for most of its victims, exposure goes completely undetected until it is too late. Every year in the UK, radon is attributed to 1,100 lung cancer deaths — making it the second leading cause of lung cancer after smoking. For smokers living or working in high-radon areas, the risks are multiplicative and severe.

Every building contains radon. It seeps up from the decay of naturally occurring uranium in rocks and soils, accumulates in the lower floors of buildings, and is inhaled with each breath. The issue is not whether radon is present — it always is — but whether its concentration has risen to a level that poses significant health risk.

Key Facts & Figures (Overview)

Highest-Risk Areas in the UK

Radon levels are determined primarily by underlying geology. Granite and limestone rocks contain higher levels of uranium and therefore produce more radon. The counties and regions with the most elevated radon concentrations in the UK are:

Cornwall — The highest-risk area in the UK. Granite bedrock throughout much of the county produces significant radon gas. Over 30% of properties in some areas exceed the action level.

Devon — Particularly Dartmoor and surrounding granite areas. Elevated radon levels broadly across the county, with particularly high concentrations on granite outcrops.

Derbyshire — The Peak District's limestone geology produces significant radon concentrations, including in the Derbyshire Dales area. Derbyshire Dales is a designated radon affected area.

Somerset — The Mendip Hills and parts of Somerset show elevated radon concentrations, primarily from limestone and uranium-bearing geology.

Northamptonshire — Parts of Northamptonshire show substantially increased radon levels, identified in HSE guidance as one of the significantly affected county areas.

Grampian and Highlands (Scotland) — Granite geology in Aberdeen and the Grampian region results in elevated radon levels. Parts of the Scottish Highlands are also affected.

Outside these primary areas, elevated radon levels have been found in pockets across other areas — including parts of Northumberland, Cumbria, Yorkshire Dales, parts of Oxfordshire, and Lincolnshire. Radon can occur at high levels in buildings anywhere in the UK, including in areas not shaded in the affected areas map. The only way to know whether a specific property has elevated radon is to test it.

How Radon Causes Lung Cancer

Radon-222 is a radioactive gas produced by the decay of uranium-238 in rocks and soils. It rises from the ground and accumulates in buildings — particularly in basements, ground floor rooms, and confined spaces. Once inhaled, radon decays further into radioactive particles (radon daughters or progeny). These particles attach to the lung tissue and emit alpha radiation directly into lung cells. Over years of exposure, this radiation damage accumulates and can initiate cancer.

Outdoors, radon dilutes rapidly in the atmosphere and presents no significant health risk. The problem is entirely a function of indoor accumulation — buildings acting as traps for a gas that would otherwise disperse harmlessly.

Employer Obligations

Radon in the workplace is a significant occupational health risk — in office environments in affected areas, radon can be the largest occupational health risk of all. Employer obligations are clear and specific:

Health and Safety at Work Act 1974 and Management of Health and Safety at Work Regulations 1999 require employers to assess and manage all significant workplace risks — including radon. In radon affected areas, risk assessment must include radon measurement in ground floor (and basement) rooms.

Ionising Radiations Regulations 1999 (IRR99): If workplace radon exceeds 400 Bq/m³, the Regulations come into force and employers are required to take formal action to reduce exposure, designate the area as a radiation area, and manage workers as radiation workers. If the level exceeds 1,000 Bq/m³, additional obligations apply.

For all below-ground workplaces — regardless of geographic location or whether the surface is in a radon affected area — radon measurements are required. Underground spaces, basements, and occupied below-ground areas can accumulate radon from surrounding soil even in areas not otherwise flagged as high risk.

The UKHSA's UKradon website (www.ukradon.org) allows employers to check whether their premises are in a radon affected area and to order workplace measurement packs.

Remediation

Where radon levels exceed action levels, remediation is typically straightforward and cost-effective. The most effective solution for most buildings is a sump and pump system — a small hole is made in the concrete floor, a pipe installed, and a low-power fan draws radon from under the floor and vents it to the outside air before it can enter the building. This typically reduces radon levels by 80–90% and costs between £500 and £2,500 to install.

Simpler measures — improving underfloor ventilation, sealing gaps in floors and service penetrations, and improving general building ventilation — may suffice in lower-risk buildings.

Written by CPD Experts

This guide was produced by the team at Online CPD Academy, a UK provider of CPD-accredited online training courses. Our health and safety, risk assessment, and ionising radiation awareness training supports employers in radon-affected areas in meeting their obligations under IRR 1999 and the HASAWA 1974.

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