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Ye Y, Shang S, Zhang Y. Theoretical model for calculating and adjusting radon activity concentration in ventilation networks of uranium mines considering pressure drop effect. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 276:107440. [PMID: 38669858 DOI: 10.1016/j.jenvrad.2024.107440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/30/2024] [Accepted: 04/20/2024] [Indexed: 04/28/2024]
Abstract
The radiation dose of workers in underground uranium mines mainly comes from radon and radon progeny. To ensure a healthy and safe work environment, it is necessary and urgent to optimize the design of ventilation systems. As such, based on the simplified radon diffusion-advection migration model of the rocks, this paper proposes 1) two methods for determining the radon exhalation rate modified by pressure drop, 2) three methods for calculating radon activity concentration of single-branch, and 3) the novel adjustment algorithm and solving procedures for calculating and adjusting the radon activity concentration in ventilation networks by modifying the radon exhalation rate, demonstrated on a specific ventilation network in a simulated underground uranium mine with calculation and analysis via MATLAB. The results show that 1) the radon exhalation rate of different branches can be modified by their pressure drop, and 2) the proposed method can be used to reveal the influences of different ventilation methods and fan pressures on the radon activity concentration in the ventilation network and the radon release rate to the atmosphere.
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Affiliation(s)
- Yongjun Ye
- School of Resources Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China; Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, Hunan, 421001, China
| | - Shanwei Shang
- School of Resources Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China
| | - Yingpeng Zhang
- School of Resources Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China
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2
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Li H, Li F, Wang S. Measurement and characteristics of radon flow in an extremely arid region based on a closed-system earth-air model. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 356:120675. [PMID: 38493642 DOI: 10.1016/j.jenvman.2024.120675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/02/2024] [Accepted: 03/13/2024] [Indexed: 03/19/2024]
Abstract
Radon (222Rn) is a radioactive gas that occurs naturally in the soil and is harmful to the environment and health. However, the measuring the amount of radon flowing is challenging. This study reveals the mechanism responsible for radon transportation and concentration variation, the main driving forces acting, and the key factors operating in the vadose zone. In this study, two separate holes were used to monitor the amount of earth-air and radon flowing in and out of the soil in the extremely arid region in China where the Mogao Grottoes are located. Using a closed-system model, the quantity, characteristics, and regularity of the flow of earth-air and radon were thus determined on daily and yearly timescales. The same patterns of variation in earth-air flow and radon concentration were found at the two sites, both depending on the variation in the atmospheric pressure (AP). When the AP decreases, earth-air flows out from the soil with a high radon concentration. Conversely, when the AP increases, earth-air enters into the soil with a low radon concentration. Thus, radon is continuously emitted from the soil. The concentration of radon in the earth-air is proportional to the rate of flow of earth-air and therefore increases as the AP decreases. The radon emission also varies with the seasonal variation in temperature and AP, which is high in summer and low in winter. On a daily timescale, the radon varies in a bimodal manner. Therefore, the net amount of radon emitted from the soil is positively correlated with the amplitude of the AP fluctuation, temperature, soil porosity, and thickness of the vadose zone. The atmospheric pumping is the main driving force responsible for the radon emission. However, the surface closure, landform, cracks, faults, grain size, pore structure, soil adsorption, basal uranium/radium, salts, wind, lunar cycle, latitude and altitude have important effects on the number of radon emission. As such, it provides a scientific basis for the effective utilization of radon and prevention of its emission from soil.
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Affiliation(s)
- Hongshou Li
- The Dunhuang Grottoes Monitoring Center of Dunhuang Academy, Dunhuang, 736200, Gansu, China.
| | - Fei Li
- The Dunhuang Grottoes Monitoring Center of Dunhuang Academy, Dunhuang, 736200, Gansu, China
| | - Shunren Wang
- The Dunhuang Grottoes Monitoring Center of Dunhuang Academy, Dunhuang, 736200, Gansu, China; Gansu Mogao Grottoes Cultural Heritage Conservation and Design Consulting Co., Ltd, China
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3
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Muhammad A, Danbatta SJ, Muhammad IY, Nasidi II. Exploring soil radon (Rn) concentrations and their connection to geological and meteorological factors. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:565-578. [PMID: 38012488 DOI: 10.1007/s11356-023-31237-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 11/21/2023] [Indexed: 11/29/2023]
Abstract
The relationship between soil radon and meteorological parameters in a region can provide insight into natural processes occurring between the lithosphere and the atmosphere. Understanding this relationship can help models establish more realistic results, rather than depending on theoretical consequences. Radon variation can be complicated to model due to the various physical variables which can affect it, posing a limitation in atmospheric studies. To predict Rn variation from meteorological parameters, a hybrid mod el called multiANN, which is a combination of multi-regression and artificial neural network (ANN) models, is established. The model was trained with 70% of the data and tested on the remaining 30%, and its robustness was tested using the Monte-Carlo method. The regions with low performance are identified and possibly related to seismic events. This model can be a good candidate for predicting Rn concentrations from meteorological parameters and establishing the lower boundary conditions in seismo-ionospheric coupling models.
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Affiliation(s)
- Ahmad Muhammad
- Department of Physics and Material Science, College of Arts and Sciences, Qatar University, P. O. Box 2713, Doha, Qatar
| | - Salim Jibrin Danbatta
- Software Engineering Department, Faculty of Engineering and Natural Sciences, Uskudar University, PK: 34662, Istanbul, Turkey.
| | - Ibrahim Yahaya Muhammad
- Theoretical and Computational Physics (TCP) Group, Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Ibrahim Isah Nasidi
- Department of Physics, Faculty of Science, Fırat University, TR-23119, Elazig, Turkey
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Dicu T, Cucoş A, Botoş M, Burghele B, Florică Ş, Baciu C, Ştefan B, Bălc R. Exploring statistical and machine learning techniques to identify factors influencing indoor radon concentration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167024. [PMID: 37709073 DOI: 10.1016/j.scitotenv.2023.167024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/10/2023] [Indexed: 09/16/2023]
Abstract
Radon is a radioactive gas with a carcinogenic effect. The malign effect on human health is, however, mostly influenced by the level of exposure. Dangerous exposure occurs predominantly indoors where the level of indoor radon concentration (IRC) is, in its turn, influenced by several factors. The current study aims to investigate the combined effects of geology, pedology, and house characteristics on the IRC based on 3132 passive radon measurements conducted in Romania. Several techniques for evaluating the impact of predictors on the dependent variable were used, from univariate statistics to artificial neural network and random forest regressor (RFR). The RFR model outperformed the other investigated models in terms of R2 (0.14) and RMSE (0.83) for the radon concentration, as a dependent continuous variable. Using IRC discretized into two classes, based on the median (115 Bq/m3), an AUC-ROC value of 0.61 was obtained for logistic regression and 0.62 for the random forest classifier. The presence of cellar beneath the investigated room, the construction period, the height above the sea level or the floor type are the main predictors determined by the models used.
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Affiliation(s)
- T Dicu
- "Constantin Cosma" Radon Laboratory (LiRaCC), Faculty of Environmental Science and Engineering, "Babeş-Bolyai" University, Fântânele Street, no. 30, Cluj-Napoca, Romania
| | - A Cucoş
- "Constantin Cosma" Radon Laboratory (LiRaCC), Faculty of Environmental Science and Engineering, "Babeş-Bolyai" University, Fântânele Street, no. 30, Cluj-Napoca, Romania.
| | - M Botoş
- Faculty of Civil Engineering, Technical University of Cluj-Napoca, C. Daicoviciu Street, no. 15, Cluj-Napoca, Romania
| | - B Burghele
- SC Radon Action SRL, Str. Mărginaşă 51, 400371 Cluj-Napoca, Romania
| | - Ş Florică
- "Constantin Cosma" Radon Laboratory (LiRaCC), Faculty of Environmental Science and Engineering, "Babeş-Bolyai" University, Fântânele Street, no. 30, Cluj-Napoca, Romania
| | - C Baciu
- "Constantin Cosma" Radon Laboratory (LiRaCC), Faculty of Environmental Science and Engineering, "Babeş-Bolyai" University, Fântânele Street, no. 30, Cluj-Napoca, Romania
| | - B Ştefan
- "Constantin Cosma" Radon Laboratory (LiRaCC), Faculty of Environmental Science and Engineering, "Babeş-Bolyai" University, Fântânele Street, no. 30, Cluj-Napoca, Romania
| | - R Bălc
- "Constantin Cosma" Radon Laboratory (LiRaCC), Faculty of Environmental Science and Engineering, "Babeş-Bolyai" University, Fântânele Street, no. 30, Cluj-Napoca, Romania
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5
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Voltattorni N, Gasparini A, Galli G. The Analysis of 222Rn and 220Rn Natural Radioactivity for Local Hazard Estimation: The Case Study of Cerveteri (Central Italy). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6420. [PMID: 37510652 PMCID: PMC10378882 DOI: 10.3390/ijerph20146420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/18/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023]
Abstract
Radon (222Rn) is the second most common cause of lung cancer after smoking. As radon poses a significant risk to human health, radon-affected areas should be identified to ensure people's awareness of risk and remediation. The primary goal of this research was to investigate the local natural radioactivity (in soils, groundwater, and indoors) because of the presence of tuff outcrops (from middle-lower Pleistocene volcanic activity) that naturally produce radioactive gas radon at Cerveteri (Rome, Central Italy). The results of the radon survey highlighted moderate (>16,000 Bq/m3) but localized anomalies in soils in correspondence with a funerary site pertaining to the Etruscan Necropolis of Cerveteri, which extends over a volcanic rock plateau. Indoor radon measurements were performed at several tuff-made dwellings, and the results showed medium-low (<200 Bq/m3) values of indoor radon except for some cases exceeding the reference level (>300 Bq/m3) recommended by the 2013/59 Euratom Directive. Although no clinical data exist regarding the health effects of thoron (220Rn) on humans, the study of 220Rn average activity concentration in the soil gas survey reveals new insights for the interpretation of radon sources that can affect dwellings, even taking into account the considerable difference in the half-lives of 222Rn and 220Rn.
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Affiliation(s)
- Nunzia Voltattorni
- Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy
| | - Andrea Gasparini
- Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy
| | - Gianfranco Galli
- Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy
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Fijałkowska-Lichwa L, Przylibski TA. Radon ( 222Rn) as a tracer in natural ventilation efficiency assessment in underground workings - an example of "St John Mine" tourist complex in Krobica (the Sudetes, SW Poland). JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 265:107225. [PMID: 37354863 DOI: 10.1016/j.jenvrad.2023.107225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/14/2023] [Accepted: 06/18/2023] [Indexed: 06/26/2023]
Abstract
The authors characterize the use of 222Rn as an effective tracer of natural ventilation of an underground site where air circulates within a whole system of workings and ventilation intensity (the number of air exchanges in the space) is determined by atmospheric factors. A radon-related database containing results of measurements conducted at various intervals and at different stages of site accessibility was compiled. During 8 months of the calendar year 222Rn activity concentration exceeds the mean annual reference value established by Polish law (300 Bq/m3). These months correspond to periods with low intensity of natural ventilation of the workings and reduced efficiency of air exchange between the site and the atmosphere. They occur in autumn - in the second half of September, in October and November, and in May in spring, and persist for 7 to even 14 days. During these periods, the time spent inside the facility which is considered safe in terms of radiation protection is limited to an average of 6-8 h a day, i.e. from 6 a.m. to 6 p.m. in October, from 11 a.m. to 6 p.m. in November and from 11 a.m. to 5 p.m. in May. The length of a safe stay in the facility is determined by atmospheric factors, mainly the air and ground temperature. The concentrations of other gases in the atmosphere inside the facility comply with Polish mining regulations.
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Affiliation(s)
- Lidia Fijałkowska-Lichwa
- Wrocław University of Science and Technology, Faculty of Civil Engineering, Wybrzeże S. Wyspiańskiego 27, 27-50-370, Wrocław, Poland.
| | - Tadeusz A Przylibski
- Wrocław University of Science and Technology, Faculty of Geoengineering, Mining and Geology, Laboratory of Geology and Planetary Sciences, Wybrzeże S. Wyspiańskiego 27, 50-370, Wrocław, Poland.
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7
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Hahn EJ, Haneberg WC, Stanifer SR, Rademacher K, Backus J, Rayens MK. Geologic, seasonal, and atmospheric predictors of indoor home radon values. ENVIRONMENTAL RESEARCH, HEALTH : ERH 2023; 1:025011. [PMID: 37701077 PMCID: PMC10496436 DOI: 10.1088/2752-5309/acdcb3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Exposure to tobacco smoke and radon cause lung cancer. Radioactive decay of naturally occurring uranium in bedrock produces radon. Seasonality, bedrock type, age of home, and topography have been associated with indoor radon, but the research is mixed. The study objective was to examine the relationships of geologic (soil radon and bedrock) and seasonal (warm and cold times of the year) factors with indoor home radon values in citizen scientists' homes over time, controlling for atmospheric conditions, topography, age of home, and home exposure to tobacco smoke. We collected and analyzed indoor radon values, soil radon gas concentrations, and dwelling- and county-level geologic and atmospheric conditions on 66 properties in four rural counties during two seasons: (1) summer 2021 (n = 53); and (2) winter/spring 2022 (n = 52). Citizen scientists measured indoor radon using Airthings radon sensors, and outdoor temperature and rainfall. Geologists obtained soil radon measurements using RAD7 instruments at two locations (near the dwelling and farther away) at each dwelling, testing for associations of indoor radon values with soil values, bedrock type, topography, and atmospheric conditions. Bedrock type, near soil radon levels, home age, and barometric pressure were associated with indoor radon. Dwellings built on carbonate bedrock had indoor radon values that were 2.8 pCi/L (103.6 Bq m-3) higher, on average, compared to homes built on siliclastic rock. Homes with higher near soil radon and those built <40 ago were more likely to have indoor radon ⩾4.0 pCi/L (148 Bq m-3). With higher atmospheric barometric pressure during testing, observed indoor radon values were lower. Seasonality and topography were not associated with indoor radon level. Understanding relationships among bedrock type, soil radon, and indoor radon exposure allows the development of practical predictive models that may support pre-construction forecasting of indoor radon potential based on geologic factors.
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Affiliation(s)
- Ellen J Hahn
- BREATHE, College of Nursing, University of Kentucky, Lexington, KY, United States of America
| | - William C Haneberg
- Kentucky Geological Survey, University of Kentucky, Lexington, KY, United States of America
| | - Stacy R Stanifer
- BREATHE, College of Nursing, University of Kentucky, Lexington, KY, United States of America
| | - Kathy Rademacher
- BREATHE, College of Nursing, University of Kentucky, Lexington, KY, United States of America
| | - Jason Backus
- Kentucky Geological Survey, University of Kentucky, Lexington, KY, United States of America
| | - Mary Kay Rayens
- BREATHE, College of Nursing, University of Kentucky, Lexington, KY, United States of America
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Salazar‐Carballo PA, López‐Pérez M, Martín‐González ME, Hernández‐Suarez F, Martín‐Luis MC. Radon Dynamics and Effective Dose Estimation in a Touristic Volcanic Cave: La Cueva del Viento, Tenerife (Canary Islands, Spain). GEOHEALTH 2023; 7:e2022GH000704. [PMID: 36789206 PMCID: PMC9911345 DOI: 10.1029/2022gh000704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 05/06/2023]
Abstract
La Cueva del Viento is a volcanic lava tube located in Tenerife Island (Canary Islands, Spain). Its touristic section, 180 m long, receives more than 28,200 visitants each year. According to the European and Spanish legislation, a radon monitoring program is required to minimize the radon exposition of workers, tourists, and cavers. In this work, we studied the radon concentration dynamics in the touristic section of the cave for ca. 1 year, using both passive and active radon detectors. Pluviometry and external air temperature played an important role in the seasonal and daily variations of indoor radon concentrations. Daily fluctuations during the dry season were analyzed using time series (Box-Jenkins methodology) and frequency analysis (Fourier and Wavelet transforms) methods. The experimental radon time-series was well-fitted using a seasonal autoregressive integrated moving average model: Seasonal Auto-Regressive Integrated Moving Average (2,0,1) (2,1,0)24, and its value, in a short-time window (ca. 1 week) was conveniently forecasted. Finally, this work revealed that the annual effective doses received, during the observation period (1 year), by the touristic guides and visitors was ca. 2 mSv/yr and 4 μSv/hr, respectively. We concluded that the touristic exploitation of La Cueva del Viento is safe for both tourists and guides. However, based on our results, La Cueva del Viento had to be classified as a "Monitoring zone" and a regular monitoring program should be implemented.
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Affiliation(s)
- Pedro A. Salazar‐Carballo
- Departamento de Medicina Física y FarmacologíaFacultad de Ciencias de la SaludUniversidad de La LagunaSan Cristóbal de La LagunaSpain
- Laboratorio de Física Médica y Radioactividad AmbientalSEGAIUniversidad de La LagunaSan Cristóbal de La LagunaSpain
| | - María López‐Pérez
- Laboratorio de Física Médica y Radioactividad AmbientalSEGAIUniversidad de La LagunaSan Cristóbal de La LagunaSpain
| | | | - Francisco Hernández‐Suarez
- Laboratorio de Física Médica y Radioactividad AmbientalSEGAIUniversidad de La LagunaSan Cristóbal de La LagunaSpain
| | - M. Candelaria Martín‐Luis
- Departamento de Biología Animal, Edafología y GeologíaFacultad de CienciasUniversidad de La LagunaSan Cristóbal de La LagunaSpain
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A continuous radon monitoring system for integration into the climate change observation network. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07894-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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10
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Cui Y, Feng S, Chen P, Ye Y, Wu Y, Li C, Yang R, Wang H. Heat-air-moisture coupled model for radon migration in a porous media. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:32659-32669. [PMID: 32514919 DOI: 10.1007/s11356-020-09374-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Radon is one of the main causes of environmental pollution and lung cancer. The precipitation of radon from porous media is affected by the coupling of heat and moisture, which has not been considered in the existing knowledge. We present a model for predicting radon migration in porous media. This model combines the heat-air-moisture (HAM) coupling model of porous media with a radon migration model to establish three-dimensional partial differential equations for steady-state radon migration under HAM coupling conditions. The finite element method (FEM) was used to obtain a numerical solution. Experimental verification showed that the model had high calculation accuracy; the calculated maximum relative error did not exceed 15%. The results of the model were compared with the results of a conventional model that does consider the coupling of heat and humidity; the results showed significant differences in the radon concentrations and radon flux distribution curves for the two models. The newly developed model revealed that there is a significant coupling effect between migration and the distribution of the temperature field, the humidity field, and radon flux in unsaturated porous media. The radon exhalation rate on the surface of porous media increases linearly with the increase of permeability. The exhalation rate decreased exponentially with the increase in relative humidity. When the trend of the temperature gradient was consistent with the concentration gradient, the radon exhalation rate decreased linearly with the increase in temperature gradient. We establish a new model to study the radon migration in porous media under the coupling of heat and moisture. The model provides a theoretical basis for an effective and accurate analysis of the impact of radon exhalation on the environment.
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Affiliation(s)
- Yu Cui
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
| | - Shengyang Feng
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China.
- Hunan Province Engineering Technology Research Center of Uranium Tailings Treatment, Hengyang, 421001, China.
| | - Puxin Chen
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
- Hunan Province Engineering Research Center of Radioactive Control Technology in Uranium Mining and Metallurgy, Hengyang, 421001, China
| | - Yongjun Ye
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
| | - Yurong Wu
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
| | - Ce Li
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
| | - Rong Yang
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
| | - Hong Wang
- School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
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11
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Fuente M, Rábago D, Goggins J, Fuente I, Sainz C, Foley M. Radon mitigation by soil depressurisation case study: Radon concentration and pressure field extension monitoring in a pilot house in Spain. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 695:133746. [PMID: 31416037 DOI: 10.1016/j.scitotenv.2019.133746] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/14/2019] [Accepted: 08/01/2019] [Indexed: 05/22/2023]
Abstract
A one-year monitoring study was conducted in a pilot house with extremely high radon levels to investigate the ability and efficiency of radon mitigation by soil depressurisation (SD) both active and passive. The study included monitoring of radon concentration, pressure field extension (PFE) under the slab and some atmospheric parameters for different testing phases. Periods in which the house remained closed to foster radon accumulation were alternated with phases of active and passive soil depressurisation under different conditions. The behaviour of the radon concentration in the pilot house was analysed along with the influence of atmospheric variables, significant correlations were found for the radon concentration with atmospheric pressure, outdoor temperature and wind. From the PFE analysis it was proven that the pressure drop with distance from the suction point of the SD system is proportional to the depressurisation generated. A behaviour law was found for the permeability characterisation of the house based on the active SD performance and also, the relationship between wind velocity and extraction airflow during passive SD operation by means of a rotating cowl was obtained. Radon reductions in excess of 85% were achieved for the different testing phases in all cases. Finally, from the results it was postulated that a fan power of 20 W is sufficient to ensure radon reductions over 85% for dwellings with similar aggregate layer and soil permeability.
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Affiliation(s)
- Marta Fuente
- School of Physics, National University of Ireland Galway, Ireland; Civil Engineering, School of Engineering, National University of Ireland Galway, Ireland; MaREI Centre for Marine, Climate and Energy, Ryan Institute, National University of Ireland Galway, Ireland.
| | | | - Jamie Goggins
- Civil Engineering, School of Engineering, National University of Ireland Galway, Ireland; MaREI Centre for Marine, Climate and Energy, Ryan Institute, National University of Ireland Galway, Ireland
| | | | | | - Mark Foley
- School of Physics, National University of Ireland Galway, Ireland.
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12
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Przylibski TA, Kaczorowski M, Fijałkowska-Lichwa L, Kasza D, Zdunek R, Wronowski R. Testing of 222Rn application for recognizing tectonic events observed on water-tube tiltmeters in underground Geodynamic Laboratory of Space Research Centre at Książ (the Sudetes, SW Poland). Appl Radiat Isot 2019; 163:108967. [PMID: 32561034 DOI: 10.1016/j.apradiso.2019.108967] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 10/17/2019] [Accepted: 10/27/2019] [Indexed: 10/25/2022]
Abstract
Research on relationships between variation in 222Rn activity concentration and tectonic events recorded using the instruments of the Geodynamic Laboratory of SRC PAS at Książ (the Sudetes, SW Poland) had been conducted since 2014. The performed analyses of variation have demonstrated the spatial character of changes in 222Rn activity concentration. Their time-course is comparable in all parts of the underground laboratory. This means that gas exchange between the lithosphere and the atmosphere occurs not only through fault zones but also through all surfaces of the underground workings: the floors, the sidewalls and the roofs. Further, some relationships between 222Rn activity concentration and tectonic activity of the orogen have been demonstrated with the use of Pearson's linear correlation coefficient. The comparison between temporal distribution (times series) of radon activity concentration and water-tube tiltmeters (WTs) demonstrated that radon data have regular oscillations which can be approximated using the sine function with a 12 month cycle (seasonal changes) and amplitude in the range of 1000-1500 Bq/m3. To compare the collected radon signal data and tectonic activity, we used linear function as the simplest method of trend assessment. Pearson's correlation coefficient r cannot be accepted as appropriate for assessing the interdependencies between variables because they do not have a normal distribution, and the relationship between them is not linear. It was noted that each series of data, namely radon activity concentration and tectonic activity determine the series of deviations above and below the trend function. Because of the non-fulfillment of the above assumptions, we used nonparametric equivalents such as Spearman's rank correlation coefficient rs and Kendall's tau. The obtained results showed that the value of the rs coefficient ranges from 0.38 to even 0.43. The best relationship at the level of rs = 0.43 was determined between the radon activity concentration recorded by detector no. 3 and the tectonic activity of the rock mass registered on the WT-2 channel. Similar at the rs level of 0.37-0.38 between detector no. 5 and 4 and the WT-2 channel. A bit higher than rs = 0.39 between detector no. 3 and the WT-2 channel. In each case, these were positive correlations. The obtained Spearman's rs coefficients indicate the correlation between 222Rn activity concentration and tectonic activity of the rock mass. The t-statistic, which analyzes the significance of Spearman's coefficient rs is a descriptive measure of the accuracy of regression matching to empirical data. It takes values in the range of percentage and provides informations about which part of the total variability of the radon activity concentration (Y) observed in the sample has been explained (determined) by regression in relation to tectonic activity of the rock mass (X). In our case, approximately f 40% to more than 50% of the radon activity concentration (Y) was explained by regression in relation to the tectonic activity of the rock mass. We obtained similar results with the use of Kendall's tau coefficient. Precise description of the character of this relationship requires further, more detailed analyses, such as comparing characteristics of the distributions based on trend variation like Monte Carlo simulation, Multivariate Adaptive Regression Splines or neural networks.
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Affiliation(s)
- Tadeusz Andrzej Przylibski
- Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, Wroclaw, 50-370, Poland
| | - Marek Kaczorowski
- Space Research Centre, Polish Academy of Sciences, Bartycka 18A, Warsaw, 00-716, Poland
| | - Lidia Fijałkowska-Lichwa
- Faculty of Civil Engineering, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, Wroclaw, 50-370, Poland
| | - Damian Kasza
- Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, Wroclaw, 50-370, Poland.
| | - Ryszard Zdunek
- Space Research Centre, Polish Academy of Sciences, Bartycka 18A, Warsaw, 00-716, Poland
| | - Roman Wronowski
- Space Research Centre, Polish Academy of Sciences, Bartycka 18A, Warsaw, 00-716, Poland
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The Importance of Checking Indoor Air Quality in Underground Historic Buildings Intended for Tourist Use. SUSTAINABILITY 2019. [DOI: 10.3390/su11030689] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article demonstrates the importance of quantifying the air quality with radon gas level as indicator in any heritage building, especially those intended for the use of people. The tourist activity or historical guide represents a typology where people spend a certain time, that is to say, in no case do they spend the same amount of hours as in their homes or jobs. Different gases that may be present in the environment must be controlled. The Séneca Square shelter, in Alicante, is a very important place for the history of the city during the Spanish Civil War that has recently been rehabilitated for exposure to people. The source of most radon gas inside a building is the ground. Many countries, including Spain, in which the building regulations, regarding the accumulation of radon gas, do not specify in their technical codes, the maximum dose that a building can sustain so that it is not harmful to people, or, the measures required to correct excessive accumulation. The possible existence of radon is verified in any underground building, regardless of the characteristics of the soil (whether granitic or not), the importance of defining and unifying the regulations that specify the different levels of radon in any architectural constructions is evident. Most of the scientific agencies in the field of medicine and health, consider that radon gas is a very harmful element for people. This element in its gaseous state is radioactive and it is present in almost all soils in which buildings are implanted, with granitic types of soil presenting higher levels of radon gas. Non-granitic soils have traditionally been considered to have very low radon levels. However, this work, providing the results of the research carried out in the underground air raid shelter in Seneca Square in Alicante (Spain), demonstrates the relevant presence of radon in non-granitic soils. This research addresses the constructive typology of the underground building and the radon presence in its interior obtained using rigorous measurement techniques.
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14
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Diurnal and Semidiurnal Cyclicity of Radon (222Rn) in Groundwater, Giardino Spring, Central Apennines, Italy. WATER 2018. [DOI: 10.3390/w10091276] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Understanding natural variations of Rn (222Rn) concentrations is the fundamental prerequisite of using this radioactive gas as a tracer, or even precursor, of natural processes, including earthquakes. In this work, Rn concentrations in groundwater were continuously measured over a seven-month period, during 2017, in the Giardino Spring, Italy, together with groundwater levels in a nearby well installed into a fractured regional aquifer. Data were processed to reduce noise, and then analyzed to produce the Fourier spectra of Rn concentrations and groundwater levels. These spectra were compared with the spectrum of tidal forces. Results showed that diurnal and semidiurnal cycles of Rn concentrations, and filtered oscillations of groundwater levels, in the nearby well, are correlated with solar and luni-solar components of tidal forces, and suggested no correlation with the principal lunar components. Therefore, influencing factors linked to solar cycles, such as daily oscillations of temperature and atmospheric pressure, and related rock deformations, may have played a role in Rn concentrations and groundwater levels. An open question remains regarding the correlation, which is documented elsewhere, of Rn concentrations and groundwater levels with the lunar components of the solid Earth tides.
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Smetanová I, Steinitz G, Holý K. MULTI-YEAR MONITORING OF RADON IN BOREHOLES AT THE MODRA GEOPHYSICAL OBSERVATORY, SLOVAKIA. RADIATION PROTECTION DOSIMETRY 2017; 177:134-139. [PMID: 29036501 DOI: 10.1093/rpd/ncx160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Long-term radon monitoring was performed in two boreholes, at a depth of 13 m in the 40 m deep V-2 borehole (August 2003-September 2005), and at 3 m depth in the 10 m deep V-3 borehole (August 2003-April 2008). Diurnal, multi-day and annual variations in radon time-series were observed. Daily average of radon activity in V-2 borehole was significantly higher and ranged from 6.5 to 383.7 kBq/m3, while in V-3 borehole only between 1.2 and 139.4 kBq/m3. The seasonal pattern was more pronounced in V-3 time series, with the maximum occurring from October to March. Multi-day variations (2-10 days) were registered in V-2 and V-3 mostly simultaneously, with higher discrepancy in spring and summer periods, when radon activity in V-3 borehole was low. Diurnal radon variations with two maxima and two minima per day were registered in both boreholes. The influence of meteorological parameters on radon concentrations was investigated. The overall impression is that seasonal variation in radon in V-3 borehole seems to be connected with the temperature variation. Multi-day variations of radon in both boreholes coincided with the atmospheric pressure changes. An increase in radon activity was observed in V-3 borehole after the rainfall in spring and summer seasons.
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Affiliation(s)
- I Smetanová
- Earth Science Institute, Slovak Academy of Sciences, Dúbravská cesta 9, 845 28 Bratislava, Slovakia
| | - G Steinitz
- Geological Survey of Israel, 30 Malkhe Israel Street, Jerusalem 95501, Israel
| | - K Holý
- Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina, 842 48 Bratislava, Slovakia
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Abstract
AbstractThis paper presents selected issues related to the use of 222Rn in therapeutic treatments. Radon is a radioactive element whose usage in medicine for more than 100 years is based on the radiation hormesis theory. However, owing to the radioactive character of this element and the fact that its alpha-radioactive decay is the source of other radionuclides, its therapeutic application has been raising serious doubts. The author points to potential sources and carriers of radon in the environment that could supply radon for use in a variety of therapies. Except for centuries-long tradition of using radon groundwaters, and later also the air in caves and underground workings, the author would also like to focus on soil air, which is still underestimated as a source of radon. The text presents different methods of obtaining this radioactive gas from groundwaters, the air in caves, mining galleries and soil air, and it presents new possibilities in this field. The author also discusses problems related to the transportation and storage of radon obtained from the environment.Within radon-prone areas, it is often necessary to de-radon groundwaters that are intended for human consumption and household usage. Also, dry radon wells are used to prevent radon migration from the ground into residential buildings. The author proposes using radon released from radon groundwaters and amassed in dry radon wells for radonotherapy treatments. Thanks to this, it is possible to reduce the cost of radiological protection of people within radon-prone areas while still exploiting the 222Rn obtained for a variety of therapies.With regard to the ongoing and still unsettled dispute concerning the beneficial or detrimental impact of radon on the human organism, the author puts special emphasis on the necessity of strictly monitoring both the activity concentration of 222Rn in media used for therapeutic treatments and of its radioactive decay products. Monitoring should be also extended to the environments in which such treatments are delivered (inhalatoriums, baths, saunas, showers, pools and other facilities), as well as to the patients – during and after the radonotherapy treatments. It is also essential to monitor the dose of radon and its daughters that is received by persons undergoing radon therapy. This should facilitate the assessment of the effectiveness of these treatments, which may contribute to a fuller understanding of the mechanisms of radon impact, and ionizing radiation in general, on the human organism. This will make it easier to ultimately confirm or reject the radiation hormesis theory. It is also essential to monitor the effective dose that is received by medical and technical staff employed to deliver the radonotherapy treatments.
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Affiliation(s)
- Tadeusz Andrzej Przylibski
- Division of Geology and Mineral Waters, Faculty of Geoengineering, Mining and Geology, Wrocław University of Technology, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland
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17
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Fijałkowska-Lichwa L, Przylibski TA. First radon measurements and occupational exposure assessments in underground geodynamic laboratory the Polish Academy of Sciences Space Research Centre in Książ Castle (SW Poland). JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 165:253-269. [PMID: 27814500 DOI: 10.1016/j.jenvrad.2016.10.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/15/2016] [Accepted: 10/17/2016] [Indexed: 06/06/2023]
Abstract
The article presents the results of the first radon activity concentration measurements conducted continuously between 17th May 2014 and 16th May 2015 in the underground geodynamic laboratory of the Polish Academy of Sciences Space Research Centre in Książ. The data were registered with the use of three Polish semiconductor SRDN-3 detectors located the closest (SRDN-3 No. 6) to and the furthest (SRDN-3 No. 3) from the facility entrance, and in the fault zone (SRDN-3 No. 4). The study was conducted to characterize the radon behaviour and check it possibility to use with reference to long- and short-term variations of radon activity concentration observed in sedimentary rocks strongly fractured and intersected by systems of multiple faults, for integrated comparative assessments of changes in local orogen kinetics. The values of radon activity concentration in the underground geodynamic laboratory of the Polish Academy of Sciences (PAN) Space Research Centre in Książ undergo changes of a distinctly seasonal character. The highest values of radon activity concentration are recorded from late spring (May/June) to early autumn (October), and the lowest - from November to April. Radon activity concentrations varied depending on the location of measurement points. Between late spring and autumn they ranged from 800 Bq·m-3 to 1200 Bq·m-3, and even 3200 Bq·m-3 in the fault zone. Between November and April, values of radon activity concentration are lower, ranging from 500 Bq·m-3 to 1000 Bq·m-3 and 2700 Bq·m-3 in the fault zone. The values of radon activity concentration recorded in the studied facility did not undergo short-term changes in either the whole annual measuring cycle or any of its months. Effective doses received by people staying in the underground laboratory range from 0.001 mSv/h to 0.012 mSv/h. The mean annual effective dose, depending on the measurement site, equals 1 or is slightly higher than 10 mSv/year, while the maximum dose exceeds 20 mSv/year. The estimated annual effective doses are comparable to the standard value of 20 mSv/year defined by Polish law for people employed in the conditions of radiation exposure. They are also in the range of annual effective dose value (8 mSv/year) recommended in workplaces by International Commission on Radiation Protection.
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Affiliation(s)
- Lidia Fijałkowska-Lichwa
- Wrocław University of Science and Technology, Faculty of Civil Engineering, Division of Geotechnics, Hydrotechnics, Underground Construction and Hydrological Engineering, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Tadeusz A Przylibski
- Wrocław University of Science and Technology, Faculty of Geoengineering, Mining and Geology, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland.
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