INTERNATIONAL COMPARISON OF CAVE RADON CONCENTRATIONS IDENTIFYING THEPOTENTIAL ALPHA-RADIATION RISKS TO BRITISH CAVE USERS

Elevated concentrations of Rn-222 have been recorded in many limestone caves throughout the world. As prolonged exposure to high radon conce ntrations has been linked to cancer and tumors, particularly of the lu ng (National Academy of Science 1988; Eatough and Henshaw 1990), a nat ional survey of radon in British caves was undertaken. Passive radon d etectors were exposed at 250 sites in 47 caves over four 7-d sampling periods. Mean concentrations ranging from 454-8,868 Bq m-3 were record ed. In one system, in the Peak District, radon concentrations of 155,0 00 Bq m-3 were recorded. The results indicate that the potential radia tion dose from a single 4-h trip could exceed the national average ann ual background radiation dose (for the UK) from radon of 1.25 mSv.