1. T. Kovács 1, J. Somlai 1, A. Kopek 2, G. Szeiler 1, G. Pomázi, Z. Sas 3, 1 University of Pannonia, Institute of Radiochemistry and Radioecology, Veszprém (Hungary) 2 Balaton Uplands National Park, Csopak (Hungary) 3 Mecsek-ÖKO Zrt, Pécs (Hungary) 4 Social Organization for Radioecological Cleanliness, Veszprém (Hungary) RADIATION DOSE ORIGINATING FROM RADON AND RADON PROGENY EFFECTING WORKERS IN THE SHOW CAVE OF TAPOLCA (HUNGARY)

2. Entrance of the show cave and the lounge

3. The show cave of Tapolca

5. 16/2000. (VI. 8.) EüM Personal dosimetry is required (inspite of the sources are terrestrial radioisotopes) in the case of the following workplaces: 26.1. Spas, caves (therapy and show caves), underground mines, other underground workplaces

6. Radon reference level for workplaces: ICRP 65 (1993): 500-1500 Bq/m 3 ICRP 103 (2007):max. 1500 Bq/m 3 ICRP (2009):max. 1000 Bq/m 3 WHO (2009):max. 1000 Bq/m 3 Hungary:max. 1000 Bq/m 3

7. Radon measurements between 12/03/2003 – 02/10/2003.

8. Average radon activity concentration (kBq/m 3 ) 12/03/2003 – 02/10/2003. Annual average >1000 Bq/m 3 Aeration is not allowed Hazardous radiation workplace Dosimetry required

9. Annual radon activity concentration in the cave and the lounge

10. Monthly average radon activity concentration in the cave and the lounge (2006 – 2011)

11. Outdoor temperature dependency of radon concentration Cave Lounge

12. Outdoor air pressure dependency of radon concentration Cave Lounge

13. Annual effective dose of workers

14. Thank you for your kind attention!