A RECONNAISSANCE SURVEY OF RADON IN SHOW CAVES IN IRELAND

摘要

A reconnaissance survey of radon gas concentrations and radon decay product concentrations in three Irish show caves was undertaken in Spring 1993. The caves, which are open to the public, are located in carboniferous limestone regions in western and southern Ireland. Area monitoring of underground radon concentrations was conducted using passive CR-39 alpha track detectors positioned at sampling locations spatially distributed along the tourist routes. Continuous radon gas measurements and decay product concentration measurements were carried out at several of these locations. Radon gas concentrations ranged from 488 to 11 285 Bq/m~3 with significant variations both within and between cave systems. The equilibrium factor, F, ranged from 0.12 to 0.71 and varied within and between caves. Estimated effective doses to tour guides ranged from 2.0 to 7.4 mSv with tourists receiving doses from 3 to 12 μSv per visit. Through individual dose assesment of guides in one of the cave systems, area monitoring was shown to give a reasonable estimate of the doses that tour guides are likely to receive.