The radiation doses received from radon by recreational cavers using caves in the mendip hills, UK

Raised radon gas levels are known to exist in mines and Show Caves, and in the United Kingdomthe Ionising Radiations Regulations 1985 require the employer to take action to reduce radonlevels by improving ventilation or restricting access, because significant radiation doses can bereceived by workers.In the Mendip Hills, where the underlying rock gives rise to raised radon levels in domesticdwellings, there are a number of cave systems with unrestricted access to recreational cavers;including youth groups.