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Benà E, Ciotoli G, Petermann E, Bossew P, Ruggiero L, Verdi L, Huber P, Mori F, Mazzoli C, Sassi R. A new perspective in radon risk assessment: Mapping the geological hazard as a first step to define the collective radon risk exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169569. [PMID: 38157905 DOI: 10.1016/j.scitotenv.2023.169569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024]
Abstract
Radon is a radioactive gas and a major source of ionizing radiation exposure for humans. Consequently, it can pose serious health threats when it accumulates in confined environments. In Europe, recent legislation has been adopted to address radon exposure in dwellings; this law establishes national reference levels and guidelines for defining Radon Priority Areas (RPAs). This study focuses on mapping the Geogenic Radon Potential (GRP) as a foundation for identifying RPAs and, consequently, assessing radon risk in indoor environments. Here, GRP is proposed as a hazard indicator, indicating the potential for radon to enter buildings from geological sources. Various approaches, including multivariate geospatial analysis and the application of artificial intelligence algorithms, have been utilised to generate continuous spatial maps of GRP based on point measurements. In this study, we employed a robust multivariate machine learning algorithm (Random Forest) to create the GRP map of the central sector of the Pusteria Valley, incorporating other variables from census tracts such as land use as a vulnerability factor, and population as an exposure factor to create the risk map. The Pusteria Valley in northern Italy was chosen as the pilot site due to its well-known geological, structural, and geochemical features. The results indicate that high Rn risk areas are associated with high GRP values, as well as residential areas and high population density. Starting with the GRP map (e.g., Rn hazard), a new geological-based definition of the RPAs is proposed as fundamental tool for mapping Collective Radon Risk Areas in line with the main objective of European regulations, which is to differentiate them from Individual Risk Areas.
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Affiliation(s)
- Eleonora Benà
- Dipartimento di Geoscienze, Università di Padova, Padova, Italy.
| | - Giancarlo Ciotoli
- Istituto di Geologia Ambientale e Geoingegneria (IGAG), Consiglio Nazionale delle Ricerche (CNR), Roma, Italy; Istituto Nazionale di Geofisica e Vulcanologia (INGV), Roma, Italy
| | - Eric Petermann
- Federal Office for Radiation Protection (BfS), Section Radon and NORM, Berlin, Germany
| | - Peter Bossew
- Federal Office for Radiation Protection (BfS), Section Radon and NORM, Berlin, Germany
| | - Livio Ruggiero
- Istituto Superiore per la Ricerca e la Protezione Ambientale (ISPRA), Roma, Italy
| | - Luca Verdi
- Provincia Autonoma di Bolzano, Laboratorio analisi aria e radioprotezione, Bolzano, Italy
| | - Paul Huber
- Azienda Sanitaria dell'Alto Adige, Bressanone, Italy
| | - Federico Mori
- Istituto di Geologia Ambientale e Geoingegneria (IGAG), Consiglio Nazionale delle Ricerche (CNR), Roma, Italy
| | - Claudio Mazzoli
- Dipartimento di Geoscienze, Università di Padova, Padova, Italy
| | - Raffaele Sassi
- Dipartimento di Geoscienze, Università di Padova, Padova, Italy
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Benkovitz A, Zafrir H, Reuveni Y. The dynamics of Rn-222 cyclic flow within the shallow geological subsurface media as a daily temporal variated source for exhalation into the air. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169244. [PMID: 38072272 DOI: 10.1016/j.scitotenv.2023.169244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/03/2023] [Accepted: 12/07/2023] [Indexed: 12/18/2023]
Abstract
Extensive research on the dynamics of radon gas (Rn-222) originating from the radioactive decay of radium (Ra-226) in geological subsurface media, sheds light on its periodic release into the atmosphere. Radon is a product of the uranium-238 decay chain found within rock and soil grains. While only a fraction of the generated radon escapes (emanates) into porous spaces due to nuclear recoil, it serves as the source for subsurface gas flows and for cyclic exhalation into the soil-atmosphere interface. Ongoing study of radon movement in shallow and deep subsoil, and its emergence at the surface, reveals complete semi-diurnal, diurnal, and seasonal gas flow cycles in the subsoil. Complementary emissions occur nocturnally as radon is released into the atmosphere. Moreover, two natural driving forces govern complex semi-diurnal and diurnal flows below and above the surface. Subsurface gas movement in porous media exhibits nonlinear behavior influenced by surface temperature gradients, resulting in downward flow to depths of up to 100 m. This flow exhibits daily periodicity with depth-dependent time delays, correlating with the diurnal surface temperature cycle. Additionally, pore gas transport into and out of open boreholes responds linearly to semi-diurnal barometric pressure changes, known as barometric pumping. Beyond subsurface phenomena, Europe and Australia increasingly employ nocturnal radon measurements to study atmospheric stability and air quality, assuming that variations in local stationary near-surface radon concentrations reflect atmospheric mixing processes. Recognizing mechanisms governing radon's temporal changes within geological subsurface media highlights the need for continuous underground radon monitoring to validate variations in daily radon exhalation to the surface. On the other hand, monitoring radon at considerable depths minimizes climatic contributions and enhances the ability to discern non-periodic pre-seismic radon signals, independent of atmospheric compulsion. This research offers potential insights into seismic precursors and the complex interplay between subsurface geodynamics and atmospheric conditions.
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Affiliation(s)
| | - Hovav Zafrir
- Faculty of Engineering, Bar-Ilan University, Ramat Gan 5290002, Israel; Geological Survey of Israel, Jerusalem 9692100, Israel
| | - Yuval Reuveni
- Department of Physics, Ariel University, Ariel 4070000, Israel; Eastern R&D Center, Ariel 4070000, Israel; School of Sustainability, Reichman University, Herzliya 4610101, Israel.
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Paasche H, Wang Y, Chand Baranwal V, Brönner M. Computation of a probabilistic uranium concentration map of Norway: A digital expert elicitation approach employing random forests and artificial neural networks. Heliyon 2023; 9:e21791. [PMID: 38027730 PMCID: PMC10660982 DOI: 10.1016/j.heliyon.2023.e21791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/27/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
We compute the first probabilistic uranium concentration map of Norway. Such a map can support mineral exploration, geochemical mapping, or the assessment of the health risk to the human population. We employ multiple non-linear regression to fill the information gaps in sparse airborne and ground-borne uranium data sets. We mimic an expert elicitation by employing Random Forests and Multi-layer Perceptrons as digital agents equally qualified to find regression models. In addition to the regression, we use supervised classification to produce conservative and alarmistic classified maps outlining regions with different potential for the local occurrence of uranium concentration extremes. Embedding the introduced digital expert elicitation in a Monte Carlo approach we compute an ensemble of plausible uranium concentrations maps of Norway discretely quantifying the uncertainty resulting from the choice of the regression algorithm and the chosen parametrization of the used regression algorithms. We introduce digitated glyphs to visually integrate all computed maps and their associated uncertainties in a loss-free manner to fully communicate our probabilistic results to map perceivers. A strong correlation between mapped geology and uranium concentration is found, which could be used to optimize future sparse uranium concentration sampling to lower extrapolation components in future map updates.
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Affiliation(s)
- Hendrik Paasche
- UFZ – Helmholtz Centre for Environmental Research GmbH, Department Monitoring and Exploration Technologies, Permoserstr. 15, 04318 Leipzig, Germany
- Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, 7040 Trondheim, Norway
| | - Ying Wang
- Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, 7040 Trondheim, Norway
| | - Vikas Chand Baranwal
- Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, 7040 Trondheim, Norway
| | - Marco Brönner
- Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, 7040 Trondheim, Norway
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Chaudhury D, Sen U, Biswas S, Shenoy P S, Bose B. Assessment of Threshold Dose of Thoron Inhalation and Its Biological Effects by Mimicking the Radiation Doses in Monazite Placer Deposits Corresponding to the Normal, Medium and Very High Natural Background Radiation Areas. Biol Trace Elem Res 2023; 201:2927-2941. [PMID: 36048359 DOI: 10.1007/s12011-022-03398-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 08/14/2022] [Indexed: 11/02/2022]
Abstract
The dose contributed from thoron (220Rn) and its progeny has been neglected in the dose assessment because of its short half-life (t1/2 = 55.6 s) and generally low concentrations. Recently, concentrations of 220Rn gas and its progeny were found to be pronounced in the traditional residential dwellings in China, on beaches of India and in other countries. Accordingly, we investigated the biological effects of thoron (220Rn) decay products in various mouse organs, succeeding inhalation of thoron gas in BALB/c mouse. We investigated the biological effects upon thoron inhalation on mouse organs with a focus on oxidative stress. These mice were divided into (4 random groups): sham inhalation, thoron inhalation for 1, 4 and 10 days. Various tissues (lung, liver and kidney) were then collected after the time points and subjected to various biochemical analyses. Immediately after inhalation, mouse tissues were excised for gamma spectrometry and 72 h post inhalation for biochemical assays. The gamma spectrometry counts and its subsequent calculation of the equivalent dose showed varied distribution in the lung, liver and kidney. Our results suggest that acute thoron inhalation showed a differential effect on the antioxidant function and exerted pathophysiological alterations via oxidative stress in organs at a higher dose. These findings suggested that thoron inhalation could alter the redox state in organs; however, its characteristics were dependent on the total redox system of the organs as well as the thoron concentration and inhalation time.
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Affiliation(s)
- Debajit Chaudhury
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Derlakatte, Mangalore, Karnataka, 575018, India
| | - Utsav Sen
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Derlakatte, Mangalore, Karnataka, 575018, India
| | - Siddhartha Biswas
- Department of Onco-Pathology, Yenepoya Medical College, Yenepoya (Deemed to be University), University Road, Derlakatte, Mangalore, Karnataka, 575018, India
| | - Sudheer Shenoy P
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Derlakatte, Mangalore, Karnataka, 575018, India.
| | - Bipasha Bose
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Derlakatte, Mangalore, Karnataka, 575018, India.
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Soldati G, Ciaccio MG, Piersanti A, Cannelli V, Galli G. Active Monitoring of Residential Radon in Rome: A Pilot Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:13917. [PMID: 36360796 PMCID: PMC9656804 DOI: 10.3390/ijerph192113917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
We present an overview of the potential of active monitoring techniques to investigate the many factors affecting the concentration of radon in houses. We conducted two experiments measuring radon concentration in 25 apartments in Rome and suburban areas for two weeks and in three apartments in the historic center for several months. The reference levels of 300 and 100 Bq/m3 are overcome in 17% and 60% of the cases, respectively, and these percentages rise to 20% and 76% for average overnight radon (more relevant for residents' exposure). Active detectors allowed us to identify seasonal radon fluctuations, dependent on indoor-to-outdoor temperature, and how radon travels from the ground to upper floors. High levels of radon are not limited to the lowest floors when the use of heating and ventilation produces massive convection of air. Lifestyle habits also reflect in the different values of gas concentration measured on different floors of the same building or in distinct rooms of the same apartment, which cannot be ascribed to the characteristics of the premises. However, the finding that high residential radon levels tend to concentrate in the historic center proves the influence of factors such as building age, construction materials, and geogenic radon.
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Janik M. Environmental Radioactivity Monitoring and Measurements: Radon and Thoron. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159276. [PMID: 35954633 PMCID: PMC9367878 DOI: 10.3390/ijerph19159276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/16/2022]
Affiliation(s)
- Miroslaw Janik
- National Institutes for Quantum Science and Technology, National Institute of Radiological Sciences, Inage, Chiba 263-8555, Japan
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Gini Method Application: Indoor Radon Survey in Kpong, Ghana. ATMOSPHERE 2022. [DOI: 10.3390/atmos13081179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study, the indoor radon concentrations map, starting from a sparse measurements survey, was realized with the Gini index method. This method was applied on a real dataset coming from indoor radon measurements carried out in Kpong, Ghana. The Gini coefficient variogram is shown to be a good estimator of the inhomogeneity degree of radon concentration because it allows for better constraining of the critical distance below which the radon geological source can be considered as uniform. The indoor radon measurements were performed in 96 dwellings in Kpong, Ghana. The data showed that 84% of the residences monitored had radon levels below 100 Bqm−3, versus 16% having levels above the World Health Organization’s (WHO) suggested reference range (100 Bqm−3). The survey indicated that the average indoor radon concentration (IRC) was 55 ± 36 Bqm−3. The concentrations range from 4–176 Bqm−3. The mean value 55 Bqm−3 is 38% higher than the world’s average IRC of 40 Bqm−3 (UNSCEAR, 1993).
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