Estimation of radon risk exposure in selected underground workplaces in the Sudetes (southern Poland)

The risk of exposure to increased ionizing radiation from radon was assessed for two groups of people who spend time, either for work (employees serving these visitors, mainly guides) or leisure (members of the public – visitors), in underground tourist facilities: Bear Cave in Kletno, the Gold Mine complex in Złoty Stok and the Underground Educational Tourist Route in the Old Uranium Mine in Kletno. These facilities had been chosen due to their location within the Sudetes, the most radon–prone area in Poland, and because of continuous radon activity concentration measurements conducted there since May 2008 to the end of January 2012. The selected facilities also meet the criteria for a radiation hazard workplace set by Polish law.The annual limit of the effective ionizing radiation dose allowed for employees in Poland, which is 20 mSv/year, is exceeded for guides working in all the facilities. Also, according to Polish radiological protection regulations, their working conditions qualify them as exposed workers of category A or B. After a month's work, guides receive the annual effective radiation dose allowed for category B workers (>1 mSv/year) and after a few months – an annual effective radiation dose allowed for people employed in category A conditions (>6 mSv/year). Members of the public spending no longer than one hour inside each facility are at risk of receiving small effective radiation doses, ranging from 0.001 to 0.2 mSv/h.