Radon in thermal waters and radon risk in chosen thermal water spas in V countries - preliminary results Karol Holý, Pavol Blahušiak, Dominik Grządziel, Tibor Kovács, Krzysztof Kozak, Jadwiga Mazur, Monika Műllerová, Erika Nagy, Martin Neznal, Matej Neznal, Amin Shahrokhi XXXVIth DAYS of RADIATION PROTECTION 10.11. -1-11-01
Rn research in thermal spas The territory of V countries is rich in thermal springs. Some boreholes reach a depth of 000 m and temperatures of water up to 70 C. Rn concentrations in some thermal waters can exceed 1000 Bq/l, however this concentration is not constant. Slovakia has about 0 spa areas, which use thermal water. Balneotherapy workplaces have higher indoor radon activity concentration (RAC). Guide values of RAC in the air of thermal spas (Government Ordinance no. 35/006) RAC defined by legislation RAC/year Investigative value of RAC 00 Bq.m -3 Guide value of radon to implement the actions 1000 Bq.m -3 Annual effective dose for some spa workers exceeds 1 msv / year, which is in accordance with applicable laws of V countries sufficient condition for the regular dosimetric control. These workers may be classified as radiation workers of category B or category A if it exceeds annual effective dose of 6 msv / year. (Government Ordinance no. 35/006) Radiation protection of staff working with geothermal water is very actual. 5.1.013 Council Directive 013/59 / Euratom - imposes an obligation to deal with the increased RAC and create action plans for radon in individual countries 1.11.01
Project V: participants Radon in thermal waters and radon risk in chosen thermal water spas in V countries - project of International Visegrad fund No.: 1303 - long tradition in use of thermal baths - monitoring of radon variations in waters and thermal spas RADON v.o.s., Praha, Czech Republic (CZ) The Henryk Niewodniczanski Institute of Nuclear Physics of Polish Academy of Sciences, Kraków, Poland (PL) Social Organisation for Radioecological Cleanliness, Veszprém, Hungary (H) Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, Comenius University, Bratislava, Slovakia (SK) 1.11.01 3
Aims Observation of radon concentration in thermal waters and air of thermal spas (indoor radon) Radon variations analysis Development of measuring methods for radon in thermal waters Assessment of annual effective doses from radon for emloyees, patients and users of thermal spas Enhancement of radon concentration monitoring and protection of spa employees - harmonization and elaboration of common measuring protocols - scientific support of national action plans for radon under the new European regulations 1.11.01
Locations chosen V thermal spas - measurements are carried out in 11 spas of V countries: CZ - 1 HU - 3 PL - 3 SK - - detectors are placed in rooms with large amounts of thermal water and in the rooms for the personal of spa - 1 3 months exposure of detectors - ownerships of the spas are currently private and spa directors have enabled us to measure only if they remain anonymous baths are marked with the identification number only 1.11.01 5
Measuring methods for Rn in thermal water Two methods of measurement were used: - ionization chamber (AlphaGUARD with AquaKIT) - liquid scintillation method Czech group uses emanometric method, in which the radon from the sample is transported to the pre-evacuated Lucas chamber with a volume of 600 ml. Hungarian group uses method, in which a sample of water is bubbled by nitrogen for a period of strip radon from water into scintilation chamber Slovak laboratory uses the vacuum emanometric method using Lucas chamber with a volume of 15 ml. Sampling: 1l glass bottle simply dipped into water or water flown in by a plastic funnel (tap water) 1.11.01 6
RAC [Bq.l -1 ] RAC [Bq.l -1 ] RAC [Bq.l -1 ] RAC comparison in thermal waters (Teplice, ČR, 5.-7..01) 80 1 Bethoven Spa Pravřídlo 60 0 3 0 00 - average 380 360 30 30 300 80 60 0 0 00 1 3 Group 10 115 110 105 100 95 90 85 80 75 70 65 60 55 50 Stone Spa pool 1 3 Group 1 3 - average 380 1 Stone Spa tap water 360 30 3 30 300 - average 80 60 0 0 00 180 160 10 10 1 3 Group 1.11.01 7
RAC [kbq.m -3 ] Conclusion relative deviations were found up to 0 % between laboratories (the largest in thermal water source Pravřídlo ), there could be problems with sampling laboratory measured systematically lower RAC values. It may be associated with: - detector calibration - with time elapsing between sampling and measurement Thermal water source: "Pravřídlo", Bethoven, sampling from the underground reservoir below water level, FEBRUARY 6, 01 0 0 1 00 380 360 30 3 30 300 80 60 0 0 5..01 6..01 7..01 8..01 9..01 10..01 11..01 1..01 Date of measurement it turns out that reproducible measurements of radon in water is not a trivial matter it would be useful to carry out a mutual measurement again 1.11.01 8
Thermal waters (Slovakia) - RAC 0 18 16 1 - very low RAC - slightly higher RAC - increased RAC - high RAC 1 N 10 8 6 0 below 0 0-50 51-00 over 00 RAC water [Bq.l -1 ] 1.11.01 9
RAC [Bq.l -1 ] Variability of the chosen thermal water source 180 average 170 160 150 10 130 10 110 100 90 3..01 3.5.01 3.6.01 3.7.01 3.8.01 3.9.01 Date of sampling 1.11.01 10
Indoor radon measurement with track detectors - comparison of three types of track detectors (English, Hungarian, Czech) - 1 3 months exposition of detectors NRPB (National Radiological Protection Board) - CR 39 plastic film placed inside antistatic holder Raduet (Radosys) - CR 39 plastic film - track detectors, which are able to measure at once Rn and 0 Rn RAMARN (SÚJBO Kamenná) - Kodak LR 115 film is located at the bottom of the diffusion chamber 1.11.01 11
Number of the rooms in spas Number of the rooms in spas Number of the rooms in spas Number of the rooms in spas RAMARN results of the first exposure 6 5 3 1 0 0-50 Czech Republic 50-00 00-00 00-1000 > 1000 RAC RamaRn [Bq.m -3 ] 1 13 1 11 10 9 8 7 6 5 3 1 0 0-50 50-00 00-00 00-1000 RAC RamaRn [Bq.m -3 ] > 1000 Poland 6 Hungary 1 11 10 Slovakia 5 9 8 7 6 3 5 3 1 1 0 0-50 50-00 00-00 00-1000 RAC RamaRn [Bq.m -3 ] > 1000 0 0-50 50-00 00-00 00-1000 RAC RamaRn [Bq.m -3 ] > 1000 1.11.01 1
Number of the rooms in spas Results of the first exposure RAMARN exposure from March till June 01 0 18 16 1 1 10 8 6 0 0-50 50-00 00-00 00-1000 > 1000 RAC RamaRn [Bq.m -3 ] Czech Republic Poland Hungary Slovakia 1.11.01 13
RAC [Bq.m -3 ] RAC [Bq.m -3 ] Detectors - comparison (Slovakia) RamaRN-s average A RN [Bq.m -3 ] difference [Bq.m -3 ] 1. exposure. exposure [Bq.m -3 ] < 00 169 ± 53 158 ± 0 11 00-1000 57 ± 113 70 ± 68 77 > 1000 7183 ± 903 560 ± 73 63 300 air temperature: 5 C 75 humidity : 75-80% 50 5 00 175 13000 1000 11000 10000 9000 8000 air temperature: 36 C humidity : 99% 150 7000 15 100 75 50 5 6000 5000 000 3000 000 1000 0 RamaRn Raduet NRPB 0 RamaRn Raduet NRPB 1.11.01 1
Slovak extrems - yet RAC - thermal waters 8 sources with RAC more than 100 Bq.l -1 1 source with RAC more than 00 Bq.l -1 RAC indoor radon + seasonal decrease 3 places with RAC between 00 1000 Bq.m -3 3 places with RAC more than 1000 Bq.m -3 : (1050 ± 1500)Bq.m -3 (6770 ± 330)Bq.m -3 decreases (8100 ± 1000)Bq.m -3 (5850 ± 370)Bq.m -3 (100 ± 10)Bq.m -3 (1060 ± 10)Bq.m -3 1.11.01 15
Conclusions We expect the acquisition of data on seasonal variations of radon in the spa facilities We will obtain information about the variability of radon in thermal waters. Data about radon variability in thermal waters are not available yet. There will be recommended repetition to improve methods of measurement of RAC in waters Conclusions will be made from the use of integral detectors for measuring radon in the air of spa facilities The results will be provided to leadership of the spas in order to decrease efective dose from radon Details for concretization of action plans 1.11.01 16
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