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Sakoda A, Ishimori Y, Jin Q, Iimoto T. Improved data analysis techniques for calculating more accurate radon and thoron exhalation rates from building interior solid walls. Appl Radiat Isot 2024; 207:111180. [PMID: 38452662 DOI: 10.1016/j.apradiso.2024.111180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/12/2023] [Accepted: 01/03/2024] [Indexed: 03/09/2024]
Abstract
The impacts of mathematical models and associated parameters on radon (222Rn) and thoron (220Rn) exhalation rates based on in-situ testing at building interior solid walls were demonstrated to improve data analysis techniques. The results showed that the heterogeneity of their activity concentrations within the measurement system was more significant for thoron than radon. The diurnal variation in indoor radon should be considered for better data quality. In conclusion, a model should be appropriately made and selected under the purposes and accuracy requirements of the exhalation test.
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Affiliation(s)
- Akihiro Sakoda
- Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan.
| | - Yuu Ishimori
- Safety and Quality Assurance Management Office, Head Office of Tsuruga Decommissioning Demonstration, Japan Atomic Energy Agency, 65-20 Kizaki, Tsuruga-shi, Fukui, 914-8585, Japan
| | - Qianhao Jin
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa campus, Chiba, 277-8561, Japan
| | - Takeshi Iimoto
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa campus, Chiba, 277-8561, Japan
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Singh KP, Chandra S, Panwar P, Joshi A, Prasad G, Gusain GS, Ramola RC. Measurement of radon concentration in soil gas and radon exhalation rate from soil samples along and across the Main Central Thrust of Garhwal Himalaya, India. Environ Geochem Health 2023; 45:8771-8786. [PMID: 37752290 DOI: 10.1007/s10653-023-01758-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/12/2023] [Indexed: 09/28/2023]
Abstract
The present study focuses on measuring radon concentrations in soil gas at various depths, radon exhalation rate (surface and mass) from soil samples, and gamma dose rate along and across the Main Central Thrust of Garhwal Himalaya, India. Radon concentration in soil gas, surface, and mass exhalation rates was measured using a portable SMART radon monitor (RnDuo). Furthermore, the gamma dose rate was measured using a pocket radiation monitor. The soil gas radon concentration varied from 15 ± 4 to 579 ± 82 Bq m-3 at a depth of 25 cm, 10 ± 2 to 533 ± 75 Bq m-3 at a depth of 30 cm, and 9 ± 1 to 680 ± 95 Bq m-3 at a depth of 35 cm. The surface and mass exhalation rates were found 3 ± 0.7 to 98 ± 3 Bq m-2 h-1 (with AM ± SD = 36 ± 28 Bq m-2 h-1) and 1 ± 0.2 to 95 ± 2 mBq kg-1 h-1 (with AM ± SD = 30 ± 22 mBq kg-1 h-1), respectively. The gamma dose rate for the present study area varies from 0.11 ± 0.05 to 0.28 ± 0.05 µSv h-1 with a mean value of 0.17 ± 0.05 µSv h-1. The correlation analysis between the exhalation rates (mass and surface) and radon concentration of soil gas at various depths was carried out in the current study.
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Affiliation(s)
- Krishna Pal Singh
- Department of Physics, P.N.G. Govt. P.G. College, Ramnagar, Nainital, 244715, India.
| | - Subhash Chandra
- Department of Physics, P.N.G. Govt. P.G. College, Ramnagar, Nainital, 244715, India
| | - Pooja Panwar
- Department of Applied Science and Engineering, Tula's Institute, Dehradun, Uttarakhand, 248197, India
| | - Abhishek Joshi
- Department of Physics, HNB Garhwal University, BadshahiThaul Campus, Tehri Garhwal, 249199, India
| | - Ganesh Prasad
- Department of Physics, B.L.J. Govt. P.G. College, Purola, Uttarkashi, 249185, India
| | - G S Gusain
- Department of Physics, Govt. P.G. College, New Tehri, Tehri Garhwal, 249001, India
| | - R C Ramola
- Department of Physics, HNB Garhwal University, BadshahiThaul Campus, Tehri Garhwal, 249199, India
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Rani S, Kundu RS, Garg VK, Singh B, Panghal A, Dilbaghi N. Radon and thoron exhalation rate in the soil of Western Haryana, India. Environ Monit Assess 2023; 195:523. [PMID: 36988758 DOI: 10.1007/s10661-023-11046-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 02/21/2023] [Indexed: 06/19/2023]
Abstract
This study reports the exhalation rates of radon and thoron from surface soil collected from 60 rural sites of district Hisar, Haryana, India. The exhalation rates of Rn222 (radon) and Rn220 (thoron) were measured by portable SMART RnDuo (AQTEK SYSTEMS) using a mass accumulation chamber which was equipped with a scintillation material-coated cell. Dose rates due to natural gamma radiations ranged from 0.526 to 1.139 mSv y-1. The Rn222 mass exhalation rate in soil samples varied from 0.14 to 94.65 mBq kg-1 h-1. Thoron surface exhalation rates ranged from 46.42 to 619.88 Bq m-2 h-1. This study gives an idea about the differences in Rn222 and Rn220 exhalation at different locations which may be due to variations in geological features of the locations and characteristics of the topsoil. The findings show that usage of study area soil as building material is safe.
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Affiliation(s)
- Shakuntala Rani
- Department of Physics, Guru Jambheshwar University of Science and Technology, Hisar, India
| | - Rajender Singh Kundu
- Department of Physics, Guru Jambheshwar University of Science and Technology, Hisar, India
| | - Vinod Kumar Garg
- Department of Environmental Science and Technology, Central University of Punjab, Bathinda, India.
| | - Balvinder Singh
- Department of Physics, Guru Jambheshwar University of Science and Technology, Hisar, India
- Centre for Radioecology, Guru Jambheshwar University of Science and Technology, Hisar, India
| | - Amanjeet Panghal
- Department of Physics, Guru Jambheshwar University of Science and Technology, Hisar, India
| | - Neeraj Dilbaghi
- Centre for Radioecology, Guru Jambheshwar University of Science and Technology, Hisar, India
- Department of Bio & Nano Technology, Guru Jambheshwar University of Science and Technology, Hisar, India
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de With G, Kovács T, Csordás A, Tschiersch J, Yang J, Sadler SW, Meisenberg O. Intercomparison on the measurement of the thoron exhalation rate from building materials. J Environ Radioact 2021; 228:106510. [PMID: 33341753 DOI: 10.1016/j.jenvrad.2020.106510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 12/01/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Thoron (220Rn) exhalation from building materials has become increasingly recognized as a potential source for radiation exposure in dwellings. However, contrary to radon (222Rn), limited information on thoron exposure is available. As a result no harmonized test procedures for determining thoron exhalation from building materials are available at present. This study is a first interlaboratory comparison of different test methods to determine the thoron exhalation and a pre-step to a harmonized standard. The purpose of this study is to compare the experimental findings from a set of three building materials that are tested, and to identify future challenges in the development of a harmonized standard.
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Affiliation(s)
- G de With
- Nuclear Research and Consultancy Group (NRG), Utrechtseweg 310, NL-6800 ES, Arnhem, the Netherlands.
| | - T Kovács
- Institute of Radiochemistry and Radioecology, University of Pannonia, 8200, Veszprem, Hungary
| | - A Csordás
- Institute of Radiochemistry and Radioecology, University of Pannonia, 8200, Veszprem, Hungary
| | - J Tschiersch
- Helmholtz Zentrum München GmbH, Former Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - J Yang
- Helmholtz Zentrum München GmbH, Former Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany; Peking University, State Key Laboratory of Nuclear Physics and Technology, 100871, Beijing, China
| | - S W Sadler
- Durridge UK Ltd. Sheffield Technology Parks, Arundel St, Sheffield, S1 2NS, UK; Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK
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Kanse SD, Sahoo BK, Gaware JJ, Sapra BK. A novel method based on 220Rn (thoron) exhalation rate of indoor surfaces for robust estimates of 220Rn concentration and equilibrium factor to compute inhalation dose. Chemosphere 2021; 267:128908. [PMID: 33213880 DOI: 10.1016/j.chemosphere.2020.128908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 11/01/2020] [Accepted: 11/05/2020] [Indexed: 06/11/2023]
Abstract
The research into 220Rn (thoron) has generated an increasing interest in recent times due to the realisation of its radiological importance in many indoor environments. Though it is assumed that the contribution of 220Rn, per se, to the inhalation dose is negligible in comparison with that of its decay products, this may not be always true. Correct estimation of inhalation dose due to thoron requires a reliable method to measure the concentration of both 220Rn and its decay products in indoor air. However, due to its very short half-life (55.6 s) 220Rn shows large variation in its indoor activity concentration. This makes it difficult to have a robust value of 220Rn concentration which can be considered representative of a house, thus making the dose estimation unreliable. This issue has been addressed in the present study by developing a novel method that utilises the 220Rn exhalation rate from indoor surfaces as the basis for estimation of average 220Rn concentration in indoor air. The 220Rn concentration estimated in this manner can be converted to decay products concentration using a suitable equilibrium factor and finally the inhalation dose using appropriate dose conversion factors. A wall mounting accumulator setup has been developed for easy in-situ measurement of 220Rn exhalation from room surfaces. The method has been validated through comprehensive measurements in 25 dwellings in two different regions of India. The developed method is very good for large scale field surveys because of fast and easy applicability.
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Affiliation(s)
- S D Kanse
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400094, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India.
| | - B K Sahoo
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400094, India
| | - J J Gaware
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400094, India
| | - B K Sapra
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400094, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India
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Frutos-Puerto S, Pinilla-Gil E, Andrade E, Reis M, Madruga MJ, Miró Rodríguez C. Radon and thoron exhalation rate, emanation factor and radioactivity risks of building materials of the Iberian Peninsula. PeerJ 2020; 8:e10331. [PMID: 33240648 PMCID: PMC7666814 DOI: 10.7717/peerj.10331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/19/2020] [Indexed: 11/20/2022] Open
Abstract
Radon (222Rn) and thoron (220Rn) are radioactive gases emanating from geological materials. Inhalation of these gases is closely related to an increase in the probability of lung cancer if the levels are high. The majority of studies focus on radon, and the thoron is normally ignored because of its short half-life (55.6 s). However, thoron decay products can also cause a significant increase in dose. In buildings with high radon levels, the main mechanism for entry of radon is pressure-driven flow of soil gas through cracks in the floor. Both radon and thoron can also be released from building materials to the indoor atmosphere. In this work, we study the radon and thoron exhalation and emanation properties of an extended variety of common building materials manufactured in the Iberian Peninsula (Portugal and Spain) but exported and used in all countries of the world. Radon and thoron emission from samples collected in the closed chamber was measured by an active method that uses a continuous radon/thoron monitor. The correlations between exhalation rates of these gases and their parent nuclide exhalation (radium/thorium) concentrations were examined. Finally, indoor radon and thoron and the annual effective dose were calculated from radon/thoron concentrations in the closed chamber. Zircon is the material with the highest concentration values of 226Ra and 232Th and the exhalation and emanation rates. Also in the case of zircon and some granites, the annual effective dose was higher than the annual exposure limit for the general public of 1 mSv y−1, recommended by the European regulations.
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Affiliation(s)
| | - Eduardo Pinilla-Gil
- Department of Analytical Chemistry, University of Extremadura, Badajoz, Spain
| | - Eva Andrade
- Laboratorio de Proteçao e Segurança Radiológica, Universidade de Lisboa, Lisboa, Portugal.,Centro de Ciencias e Tecnologias Nucleares, Bobadela, Portugal
| | - Mário Reis
- Laboratorio de Proteçao e Segurança Radiológica, Universidade de Lisboa, Lisboa, Portugal.,Centro de Ciencias e Tecnologias Nucleares, Bobadela, Portugal
| | - María José Madruga
- Laboratorio de Proteçao e Segurança Radiológica, Universidade de Lisboa, Lisboa, Portugal.,Centro de Ciencias e Tecnologias Nucleares, Bobadela, Portugal
| | - Conrado Miró Rodríguez
- Centro de Ciencias e Tecnologias Nucleares, Bobadela, Portugal.,Department of Applied Physics, University of Extremadura, Cáceres, Spain
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Yang J, Busen H, Scherb H, Hürkamp K, Guo Q, Tschiersch J. Modeling of radon exhalation from soil influenced by environmental parameters. Sci Total Environ 2019; 656:1304-1311. [PMID: 30625659 DOI: 10.1016/j.scitotenv.2018.11.464] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/08/2018] [Accepted: 11/30/2018] [Indexed: 06/09/2023]
Abstract
Atmospheric radioactive noble gas radon (Rn-222) originates from soil gas exhaled in the atmospheric surface layer. Radon exhalation rates from soil as well as corresponding meteorological and soil parameters were recorded for two subsequent years. Based on long-term field data, a statistical regression model for the radon exhalation and the most important influencing parameters soil water content, temperature of soil and air, air pressure and autocorrelation of the exhalation rate was established. The fitting result showed that the multivariate model can explain up to 61% of the variation of the exhalation rate. First, the exhalation rate increases up to 80 Bq m-2 h-1 with increasing soil water content. Later, at water content >10%, increasing soil wetness suppressed the exhalation rate: at values higher than 24% to approximately one third. The air temperature had a distinct positive effect while the soil temperature had a strong negative effect on the exhalation rate, indicating their different influencing-mechanisms on the exhalation. The air pressure was negligible. The lagged values of radon exhalation had to be included in the model, as the variable shows strong autocorrelation.
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Affiliation(s)
- Jinmin Yang
- Helmholtz Zentrum München, Institute of Radiation Protection, 85764 Neuherberg, Germany; State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China.
| | - Hannah Busen
- Helmholtz Zentrum München, Institute of Computational Biology, 85764 Neuherberg, Germany.
| | - Hagen Scherb
- Helmholtz Zentrum München, Institute of Computational Biology, 85764 Neuherberg, Germany
| | - Kerstin Hürkamp
- Helmholtz Zentrum München, Institute of Radiation Protection, 85764 Neuherberg, Germany.
| | - Qiuju Guo
- State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing, China.
| | - Jochen Tschiersch
- Helmholtz Zentrum München, Institute of Radiation Protection, 85764 Neuherberg, Germany.
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López-Coto I, Mas JL, Vargas A, Bolívar JP. Studying radon exhalation rates variability from phosphogypsum piles in the SW of Spain. J Hazard Mater 2014; 280:464-471. [PMID: 25194815 DOI: 10.1016/j.jhazmat.2014.07.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/15/2014] [Accepted: 07/07/2014] [Indexed: 06/03/2023]
Abstract
Nearly 1.0 × 10(8) tonnes of phosphogypsum were accumulated during last 50 years on a 1,200 ha disposal site near Huelva town (SW of Spain). Previous measurements of exhalation rates offered very variable values, in such a way that a worst case scenario could not be established. Here, new experimental data coupled to numerical simulations show that increasing the moisture contents or the temperature reduces the exhalation rate whilst increasing the radon potential or porosity has the contrary effect. Once the relative effects are compared, it can be drawn that the most relevant parameters controlling the exhalation rate are radon potential (product of emanation factor by (226)Ra concentration) and moisture saturation of PG. From wastes management point of view, it can be concluded that piling up the waste increasing the height instead of the surface allows the reduction of the exhalation rate. Furthermore, a proposed cover here is expected to allow exhalation rates reductions up to 95%. We established that the worst case scenario corresponds to a situation of extremely dry winter. Under these conditions, the radon exhalation rate (0.508 Bqm(-2)s(-1)) would be below though close to the upper limit established by U.S.E.P.A. for inactive phopsphogypsum piles (0.722 Bqm(-2)s(-1)).
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Affiliation(s)
- I López-Coto
- Dpto. Física Aplicada, Facultad CC. Experimentales, University of Huelva, Campus de El Carmen s/n, 21007 Huelva, Spain.
| | - J L Mas
- Dpto. Física Aplicada I. Escuela Politécnica Superior, University of Sevilla, C/Virgen de Africa 7, 41012 Sevilla, Spain
| | - A Vargas
- Universitat Politècnica de Catalunya, Instituto de Técnicas Energéticas, Campus Sud Edificio ETSEIB, Planta 0, Pabellón C, Av. Diagonal 647, 08028 Barcelona, Spain
| | - J P Bolívar
- Dpto. Física Aplicada, Facultad CC. Experimentales, University of Huelva, Campus de El Carmen s/n, 21007 Huelva, Spain
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