1
|
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.
Collapse
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
| |
Collapse
|
2
|
Dardac M, Elío J, Aghdam MM, Banríon M, Crowley Q. Application of airborne geophysical survey data in a logistic regression model to improve the predictive power of geogenic radon maps. A case study in Castleisland, County Kerry, Ireland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 894:164965. [PMID: 37343860 DOI: 10.1016/j.scitotenv.2023.164965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 06/23/2023]
Abstract
In this study, a novel methodology was investigated to improve the spatial resolution and predictive power of geogenic radon maps. The data inputs comprise indoor radon measurements and seven geogenic factors including geological data (i.e. bedrock and Quaternary geology, aquifer type and soil permeability) and airborne geophysical parameters (i.e. magnetic field strength, gamma-ray radiation and electromagnetic resistivity). The methodology was tested in Castleisland southwest Ireland, a radon-prone area identified based on the results of previous indoor radon surveys. The developed model was capable of justifying almost 75 % of the variation in geogenic radon potential. It was found that the attributes with the greatest statistical significance were equivalent uranium content (EqU) and soil permeability. A new radon potential map was produced at a higher spatial resolution compared with the original map, which did not include geophysical parameter data. In the final step, the activity of radon in soil gas was measured at 87 sites, and the correlation between the observed soil gas radon and geophysical properties was evaluated. The results indicate that any model using only geophysical data cannot accurately predict soil radon activity and that geological information should be integrated to achieve a successful prediction model. Furthermore, we found that EqU is a better indicator for predicting indoor radon potential than the measured soil radon concentrations.
Collapse
Affiliation(s)
- Mirela Dardac
- Geology, School of Natural Sciences, Trinity College Dublin, Ireland.
| | - Javier Elío
- Western Norway University of Applied Sciences, Bergen, Norway
| | - Mirsina M Aghdam
- Geology, School of Natural Sciences, Trinity College Dublin, Ireland.
| | - Méabh Banríon
- Geology, School of Natural Sciences, Trinity College Dublin, Ireland.
| | - Quentin Crowley
- Geology, School of Natural Sciences, Trinity College Dublin, Ireland.
| |
Collapse
|
3
|
Mousavi Aghdam M, Crowley Q, Rocha C, Dentoni V, Da Pelo S, Long S, Savatier M. A Study of Natural Radioactivity Levels and Radon/Thoron Release Potential of Bedrock and Soil in Southeastern Ireland. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18052709. [PMID: 33800209 PMCID: PMC7967442 DOI: 10.3390/ijerph18052709] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/28/2022]
Abstract
Radon (222Rn) and thoron (220Rn) account for almost two-thirds of the annual average radiation dose received by the Irish population. A detailed study of natural radioactivity levels and radon and thoron exhalation rates was carried out in a legislatively designated “high radon” area, as based on existing indoor radon measurements. Indoor radon concentrations, airborne radiometric data and stream sediment geochemistry were collated, and a set of soil samples were taken from the study area. The exhalation rates of radon (E222Rn) and thoron (E220Rn) for collected samples were determined in the laboratory. The resultant data were classified based on geological and soil type parameters. Geological boundaries were found to be robust classifiers for radon exhalation rates and radon-related variables, whilst soil type classification better differentiates thoron exhalation rates and correlated variables. Linear models were developed to predict the radon and thoron exhalation rates of the study area. Distribution maps of radon and thoron exhalation rates (range: E222Rn [0.15–1.84] and E220Rn [475–3029] Bq m−2 h−1) and annual effective dose (with a mean value of 0.84 mSv y−1) are presented. For some parts of the study area, the calculated annual effective dose exceeds the recommended level of 1 mSv y−1, illustrating a significant radiation risk. Airborne radiometric data were found to be a powerful and fast tool for the prediction of geogenic radon and thoron risk. This robust method can be used for other areas where airborne radiometric data are available.
Collapse
Affiliation(s)
- Mirsina Mousavi Aghdam
- Department of Civil and Environmental Engineering and Architecture, University of Cagliari, 09123 Cagliari, Italy;
- Department of Geology, School of Natural Sciences, Trinity College, D02PN40 Dublin, Ireland;
- Correspondence:
| | - Quentin Crowley
- Department of Geology, School of Natural Sciences, Trinity College, D02PN40 Dublin, Ireland;
| | - Carlos Rocha
- Biogeochemistry Research Group, School of Natural Sciences, Trinity College, D02PN40 Dublin, Ireland; (C.R.); (M.S.)
| | - Valentina Dentoni
- Department of Civil and Environmental Engineering and Architecture, University of Cagliari, 09123 Cagliari, Italy;
| | - Stefania Da Pelo
- Department of Chemical and Geological Sciences, University of Cagliari, 09042 Cagliari, Italy;
| | - Stephanie Long
- Environmental Protection Agency of Ireland, D14YR62 Dublin, Ireland;
| | - Maxime Savatier
- Biogeochemistry Research Group, School of Natural Sciences, Trinity College, D02PN40 Dublin, Ireland; (C.R.); (M.S.)
| |
Collapse
|
4
|
Long-Term Measurements of Radon and Thoron Exhalation Rates from the Ground Using the Vertical Distributions of Their Activity Concentrations. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041489. [PMID: 33557427 PMCID: PMC7915545 DOI: 10.3390/ijerph18041489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 11/16/2022]
Abstract
A long-term measurement technique of radon exhalation rate was previously developed using a passive type radon and thoron discriminative monitor and a ventilated type accumulation chamber. In the present study, this technique was applied to evaluate the thoron exhalation rate as well, and long-term measurements of radon and thoron exhalation rates were conducted for four years in Gifu Prefecture. The ventilated type accumulation chamber (0.8 × 0.8 × 1.0 m3) with an open bottom was embedded 15 cm into the ground. The vertical distributions of radon and thoron activity concentrations from the ground were obtained using passive type radon-thoron discriminative monitors (RADUETs). The RADUETs were placed at 1, 3, 10, 30, and 80 cm above the ground inside the accumulation chamber. The measurements were conducted from autumn 2014 to autumn 2018. These long-term results were found to be in good agreement with the values obtained by another methodology. The radon exhalation rates from the ground showed a clearly seasonal variation. Similar to findings of previous studies, radon exhalation rates from summer to autumn were relatively higher than those from winter to spring. In contrast, thoron exhalation rates were not found to show seasonal variation.
Collapse
|
5
|
Continuous radon monitoring during seven years of volcanic unrest at Campi Flegrei caldera (Italy). Sci Rep 2020; 10:9551. [PMID: 32533027 PMCID: PMC7293226 DOI: 10.1038/s41598-020-66590-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/13/2020] [Indexed: 02/01/2023] Open
Abstract
This is a seven-year study (1/7/2011-31/12/2017) of radon monitoring at two sites of Campi Flegrei caldera (Neaples, Southern Italy) that in the last 70 years experienced repeated phases of volcanic unrest. The sites are equipped with devices for radon detection, based on the spectrometry analysis of the α-particles of radon daughters. A hybrid method, as combination of three known methods, is applied for the identification of residuals (anomalies) and trends of the time series of Radon. The results are compared with the following indicators of current caldera unrest: the tremor caused by the major fumarolic vent registered by a seismic station; the cumulative of background seismicity; the maximum vertical deformation acquired by GPS networks during the current phase of uplift; the temperature-pressure of the hydrothermal system estimated based on gas geo-indicators. The comparisons show strong correlation among independent signals and suggest that the extension of the area affected by current Campi Flegrei crisis is larger than the area of seismicity and of intense hydrothermal activity from which the radon stations are 1–4 km away. These results represent an absolute novelty in the study of a such calderic area and mark a significant step forward in the use and interpretation of the radon signal.
Collapse
|
6
|
Daniela G, Carloni S, Voltaggio M, Di Lisa GA. PRE-ANTHROPIC AND PRESENT OUTDOOR GAMMA EQUIVALENT DOSE RATE OF THE HISTORIC CENTER OF ROME (ITALY). RADIATION PROTECTION DOSIMETRY 2019; 187:518-534. [PMID: 31702770 DOI: 10.1093/rpd/ncz247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 07/15/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
The outdoor gamma background of the historic center of Rome was studied by in situ measurements and average values of the outcropping geological formations. The survey resulted in two maps of dose equivalent rate, related to pre-anthropic and present conditions. Presently, the average of the dose equivalent rate from outdoor gamma-ray field is equal to 0.31 μSv h-1, corresponding to an outdoor annual effective dose equivalent of 0.548 mSv a-1 and to an outdoor excess lifetime cancer risk [International Commission on Radiological Protection (ICRP). Recommendations of the ICRP, 21, 1/3, Publication 60, 1990] of 2.56 × 10-3. The originary radioactivity was enhanced by anthropic action up to a level of health risk comparable to that one deriving by fine particulate matter. The assessment of the evolution and dispersion of the outdoor gamma background offers a new perspective to study the urban architectural evolution. Such a mapping allows us to individuate mitigation actions and neighborhoods in which the monitoring of illicit trafficking of radioactive material can be efficiently tested.
Collapse
Affiliation(s)
- Guglietta Daniela
- Institute of Environmental Geology and Geoengineering (IGAG-CNR), Area della Ricerca Roma 1, Strada Provinciale 35d, km 0.700, Montelibretti, 00010, RM, Italy
| | - Serena Carloni
- Institute of Environmental Geology and Geoengineering (IGAG-CNR), Area della Ricerca Roma 1, Strada Provinciale 35d, km 0.700, Montelibretti, 00010, RM, Italy
| | - Mario Voltaggio
- Institute of Environmental Geology and Geoengineering (IGAG-CNR), Area della Ricerca Roma 1, Strada Provinciale 35d, km 0.700, Montelibretti, 00010, RM, Italy
| | | |
Collapse
|