Why Radon is the Biggest Risk

⚙️ Why Radon is the Biggest Risk

Of all background radiation sources, radon gas deserves special attention because it is both the largest source and because its mechanism of harm is particularly well understood.

Radon-222 is produced by the radioactive decay chain of uranium-238, which is present in many types of rock (especially granite) and in soil. Radon is a gas, which means it can seep up through cracks and pores in the ground and enter buildings — particularly basements and ground floors with poor ventilation.

When radon decays, it emits alpha particles (helium nuclei, highly ionising). When radon is inhaled and decays inside the lungs, these alpha particles are absorbed completely by the sensitive lung tissue, depositing all their energy and causing significant cell damage. Long-term exposure to high radon levels is linked to increased risk of lung cancer.

The risk is highest in areas with granite geology (Cornwall, Devon, parts of Scotland). Remedies include improving ventilation, sealing floors, and installing radon sumps. The UK government has identified "Radon Affected Areas" where testing and mitigation are recommended.