RESUMEN
We investigated the effect of air purifier for reducing the indoor radon exposure by continuously measuring the radon (Rn), attached radon decay products (DaRn) and unattached radon decay products (DuRn). The results showed that the air purifier can effectively reduce the concentration of DaRn and DuRn except Rn. The results showed that the air purifier can be a helpful supplement to the existing radon mitigation methods.
Asunto(s)
Filtros de Aire , Contaminantes Radiactivos del Aire/aislamiento & purificación , Contaminación del Aire Interior/análisis , Hijas del Radón/aislamiento & purificación , Radón/aislamiento & purificación , Humanos , Monitoreo de Radiación/métodosRESUMEN
Radon gas has been declared a human carcinogen by the United States Environmental Protection Agency (USEPA) and the International Agency for Research on Cancer (IARC). Several studies carried out in Spain highlighted the high radon concentrations in several regions, with Galicia (northwestern Spain) being one of the regions with the highest radon concentrations. The objective of this work was to create a safe and low-cost radon monitoring and alert system, based on open source technologies. To achieve this objective, the system uses devices, a collection of sensors with a processing unit and a communication module, and a backend, responsible for managing all the information, predicting radon levels and issuing alerts using open source technologies. Security is one of the largest challenges for the internet of things, and it is utterly important in the current scenario, given that high radon concentrations pose a health risk. For this reason, this work focuses on securing the entire end-to-end communication path to avoid data forging. The results of this work indicate that the development of a low-cost, yet secured, radon monitoring system is feasible, allowing one to create a network of sensors that can help mitigate the health hazards that high radon concentrations pose.
Asunto(s)
Exposición a Riesgos Ambientales , Monitoreo del Ambiente , Radón/aislamiento & purificación , Contaminación del Aire Interior/prevención & control , Humanos , Radón/toxicidad , Factores de Riesgo , España , Estados UnidosRESUMEN
Objective: To explore whether there is a possible problem regarding indoor radon concentration surpassing the new European Directive 2013/59/Euratom threshold in Spanish workplaces. We also aim to find out whether radon concentration might be associated with certain characteristics of workplaces. Method: We performed a cross-sectional study to measure indoor radon concentrations in Spanish workplaces including five different sectors (education, public administration, the health sector, the tourist sector and the private sector). To be measured, the workplace should be occupied permanently by at least one worker. Alpha-track type radon detectors were placed for at least three months and read at the Galician Radon Laboratory at the University of Santiago de Compostela. A descriptive analysis was performed on radon distribution by sector, building characteristics and number of workers affected. Results: We faced enormous difficulties in finding volunteers for this study. Galicia and Madrid had the highest number of measurements. Of a total of 248 measurements, 27% had concentrations above 300 Bq/m3. Median radon concentration was 251 Bq/m3 in Galicia, followed by Madrid, with 61.5 Bq/m3. Forty-six percent of the workplaces measured in Galicia had radon concentrations higher than 300 Bq/m3 followed by 10.6% in Madrid. Nineteen percent of all workers were exposed to more than 300 Bq/m3 and 6.3% were exposed to radon concentrations higher than 500 Bq/m3. Conclusion: Indoor radon exposure might be a relevant problem in Spanish workplaces and the number of affected workers could be high. The prevalence of workers exposed to high radon concentrations probably depends on the geographical area
Objetivo: Explorar si podría existir un problema en cuanto a la concentración de radón en los puestos de trabajo en España por superación del umbral propuesto por la nueva Directiva Europea 2013/59/Euratom. También se pretende conocer si la concentración de radón puede estar asociada a las características de los puestos de trabajo. Método: Estudio transversal en seis regiones y diferentes sectores (educación, administración pública, sanitario, turístico y privado). El puesto de trabajo medido debía ser ocupado de manera permanente por al menos un trabajador. Los detectores de radón de tipo alfa-track estuvieron colocados al menos 3 meses y fueron revelados en el Laboratorio de Radón de Galicia, de la Universidad de Santiago de Compostela. Se realizó un análisis descriptivo de la concentración de radón por sector, por características de los edificios y por número de trabajadores afectados. Resultados: Hubo dificultades para encontrar voluntarios para este estudio. Galicia y Madrid tuvieron el mayor número de mediciones. Se midieron 248 lugares de trabajo, con el 27% por encima de los 300 Bq/m3. La concentración mediana fue de 251 Bq/m3 en Galicia, seguida de Madrid con 61,5 Bq/m3. El 46% de los puestos de trabajo en Galicia tenían concentraciones mayores de 300 Bq/m3, y el 10,6% en Madrid. El 19% de los trabajadores estuvieron expuestos a más de 300 Bq/m3 y el 6,3% a más de 500 Bq/m3. Conclusión: La exposición a radón podría ser un problema de salud relevante en los lugares de trabajo en España. El número de trabajadores expuestos parece elevado. La prevalencia de trabajadores afectados depende del área geográfica
Asunto(s)
Humanos , Radón/aislamiento & purificación , Contaminantes Radiactivos del Aire/análisis , Contaminación del Aire Interior/análisis , Contaminantes Ocupacionales del Aire/análisis , Neoplasias Pulmonares/epidemiología , Contaminación Radiactiva del Aire/análisis , Estudios Transversales , España/epidemiología , Monitoreo de Radiación/métodosRESUMEN
BACKGROUND: The waterborne or airborne radon causes carcinogenesis in the human bodies due to the continuous decay of α- and ß- particles. The health risks related to radioactive radon instigate to develop an advanced technology for its removal from the environment. There are two standard techniques, such as aeration and activated carbon filtration, available for its removal. However, both of them face different technological drawbacks resulting in the processes either inefficient or inappropriate for the purpose. CONCLUSION: There are several technologies utilizing either algae or microorganisms that could be useful in the bioremediation of radon. Some of the algae and microorganisms are examined and found to be tolerated and decontaminated various ionization radiations like α-, ß-, and γ- radiations. In a US patent, the microalgae Coccomyxa actinabiotis isolated from a nuclear facility showed the properties of bioremediation towards radionuclides. They overcome the physiological stress in the extreme environment for their growth due to the evolution under the prolonged influence of high energy radiation. Further, they are stimulated by the process of cloning, genetic transformations and adaptations for the purpose of enhancing the tolerance and decontamination power. Therefore, biotechnological researches have lots of prospects to remove radon from the water environment using algae and microorganisms.
Asunto(s)
Biodegradación Ambiental , Radón/metabolismo , Contaminantes Químicos del Agua/metabolismo , Adsorción , Archaea/crecimiento & desarrollo , Archaea/metabolismo , Carbón Orgánico/química , Chlorophyta/crecimiento & desarrollo , Chlorophyta/metabolismo , Agua Dulce/química , Patentes como Asunto , Radón/química , Radón/aislamiento & purificación , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodosRESUMEN
Tank waters from 13 Community Groundwater Systems (CGS) showed average radon reduction rate of 26.5% (varying from -17.9% to 63.3%). When applying the reduction rate of 26.5% to the nationwide CGS, the percentage of CGS having radon level above 100Bq/L decreases from 28.8% to 22.0%. The natural radon reduction method would be applied to the CGS having radon level slightly exceeding guideline of WHO, as an alternative for aeration or GAC.
Asunto(s)
Radón/análisis , Contaminantes Radiactivos del Agua/análisis , Agua Subterránea/análisis , Humanos , Monitoreo de Radiación , Radón/aislamiento & purificación , República de Corea , Contaminantes Radiactivos del Agua/aislamiento & purificación , Purificación del Agua , Abastecimiento de AguaRESUMEN
Available radon mitigation results were gathered for 85 houses mainly by installing sub-slab depressurization systems (SSDS) with two types of discharge and fan locations: Above ground level discharge with the fan located in the basement (AGL) or above roof line discharge with the fan located in the attic (ARL). A comparative analysis was made of mitigation efficiency and of exhaust icing. Results show that both SSDS scenarios reduced radon levels similarly. The results of SSDS with AGL show that a sealed radon fan having proper fittings and sealed piping was able to reduce the radon to acceptable levels, and that these installations were less subject to obstructive icing of the exhaust in cold climates.
Asunto(s)
Contaminantes Radiactivos del Aire/aislamiento & purificación , Contaminación del Aire Interior/prevención & control , Contaminación Radiactiva del Aire/prevención & control , Clima Frío , Radón/aislamiento & purificación , Canadá , Vivienda , Humanos , Presión , Monitoreo de RadiaciónRESUMEN
The primary objective of this study was to investigate the temporal variability between basement winter short-term (7 to 10 d) and basement annual radon measurements. Other objectives were to test the short-term measurement's diagnostic performance at two reference levels and to evaluate its ability to predict annual average basement radon concentrations. Electret ion chamber (short-term) and alpha track (annual) radon measurements were obtained by trained personnel in Iowa residences. Overall, the geometric mean of the short-term radon concentrations (199 Bq m) was slightly greater than the geometric mean of the annual radon concentrations (181 Bq m). Short-term tests correctly predicted annual radon concentrations to be above the 148 Bq m action level 88% of the time and above a 74 Bq m level 98% of the time. The short-term and annual radon concentrations were strongly correlated (r = 0.87, p < 0.0001). The foundation wall material of the basement was the only significant factor to have an impact on the absolute difference between the short-term and annual measurements. The findings from this study provide evidence of a substantially lower likelihood of obtaining a false negative result from a single short-term test in a region with high indoor radon potential when the reference level is lowered to 74 Bq m.
Asunto(s)
Vivienda , Monitoreo de Radiación/métodos , Radón/análisis , Estaciones del Año , Adulto , Anciano , Toma de Decisiones , Restauración y Remediación Ambiental , Femenino , Humanos , Modelos Lineales , Persona de Mediana Edad , Control de Calidad , Radón/aislamiento & purificación , Factores de TiempoRESUMEN
A study to determine the long term effectiveness of commonly used radon remedial methods over a 15 year period is discussed. The overall failure rate for remediation systems was 63%, with roughly equal rates for passive and active type systems. The fans used in active systems performed better than expected, with many of them exceeding manufacturers' stated life spans by several years. The study found that all types of remedial measure can last more than ten years, but also found examples for all measures that failed in less than five years. This supports HPA advice that homes should be retested every 5-10 years. It was also noted that householders found it difficult to detect failures in passive systems. The need for a follow-up study is discussed, in light of likely changes in building practices and materials during the last twenty years.
Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Contaminación del Aire Interior/prevención & control , Monitoreo del Ambiente/estadística & datos numéricos , Restauración y Remediación Ambiental/estadística & datos numéricos , Vivienda/estadística & datos numéricos , Protección Radiológica/estadística & datos numéricos , Radón/aislamiento & purificación , Contaminación del Aire Interior/estadística & datos numéricos , Vivienda/tendencias , Estudios Longitudinales , Dosis de Radiación , Radiometría/estadística & datos numéricos , Radiometría/tendencias , Reino UnidoRESUMEN
Activity of (226)Ra in radium daughter products free solution was determined by 4πα liquid scintillation counting (LSC) method, where the detection efficiency of radium decay is practically equal to 1. The sources were prepared from solution with known (226)Ra mass concentration, from which, immediately before LS counting, (222)Rn and its daughter nuclides were removed by solvent extraction. LS counting results were corrected practically only for a <0.6% loss of radium from measured sample and for the ingrowth of (222)Rn and (218)Po concentrations in the sample after the separation was completed. The combined relative standard uncertainty was estimated to be lower than 0.34%.
Asunto(s)
Extracción Líquido-Líquido/métodos , Polonio/aislamiento & purificación , Radio (Elemento)/análisis , Radio (Elemento)/normas , Radón/aislamiento & purificación , Conteo por Cintilación/métodos , Conteo por Cintilación/normas , República Checa , Polonio/análisis , Dosis de Radiación , Radón/análisisRESUMEN
The recent interest for measuring (220)Rn activity in air and the following development of the corresponding measurement techniques require the improvement of standards for the calibration and characterization of the measurement devices. Due to the short half-life of the (220)Rn, the adopted techniques for the production of (222)Rn sources are not always reliable. In this paper a methodology for realizing a thoron known activity starting from a (232)Th source will be presented and discussed.
Asunto(s)
Radiometría/métodos , Radiometría/normas , Radón/análisis , Radón/aislamiento & purificación , Torio/análisis , Torio/aislamiento & purificación , Calibración , Italia , Dosis de Radiación , Valores de ReferenciaRESUMEN
In Ireland radon is a significant public health issue and is linked to 150-200 lung cancer deaths each year. Irish National Radon Policy aims to reduce individual risk by identifying and remediating buildings with high radon concentrations and also to reduce collective dose through radon prevention as required by revised building regulations. Achievements to date are significant and include the completion of the National Radon Survey, the testing of every school in Ireland, the on-going testing of social housing, collaboration between the public health and radiation protection authorities and the inclusion of radon in inspections of workplaces. However, this work now needs to be drawn together centrally to comprehensively address the radon problem. The RPII and the relevant central governing department, the Department of Environment, Heritage and Local Government are currently working to constitute a group of key experts from relevant public authorities to drive the development of a National Radon Control Strategy.
Asunto(s)
Contaminación Radiactiva del Aire/prevención & control , Exposición a Riesgos Ambientales/legislación & jurisprudencia , Programas Nacionales de Salud , Protección Radiológica/legislación & jurisprudencia , Radón/aislamiento & purificación , Exposición a Riesgos Ambientales/prevención & control , Humanos , IrlandaRESUMEN
Deposition-based (222)Rn and (220)Rn progeny sensors act as unique, passive tools for determining the long time-averaged progeny deposition fluxes in the environment. The use of these deposition sensors as progeny concentration monitors was demonstrated in typical indoor environments as conceptually superior alternatives to gas-based indirect monitoring methods. In the present work, the dependency of these deposition monitors on various environmental parameters is minimized by capping the deposition sensor with a suitable wire mesh. These wire-mesh capped deposition sensors measure the coarse fraction deposition flux, which is less dependent on the change in environmental parameters like ventilation rate and turbulence. The calibration of these wire-mesh capped coarse fraction progeny sensors was carried out by laboratory controlled experiments. These sensors were deployed both in indoor and in occupational environments having widely different ventilation rates. The obtained coarse fraction deposition velocities were fairly constant in these environments, which further confirmed that the signal on the wire-mesh capped sensors show the least dependency on the change in environmental parameters. This technique has the potential to serve as a passive particle sizer in the general context of nanoparticles using progeny species as surrogates. On the whole, there exists a strong case for developing a passive system that responds only to coarse fraction for providing alternative tools for dosimetry and environmental fine particle research.
Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Contaminación del Aire Interior/estadística & datos numéricos , Monitoreo de Radiación/instrumentación , Radón/análisis , Movimientos del Aire , Contaminantes Radiactivos del Aire/aislamiento & purificación , Cinética , Monitoreo de Radiación/métodos , Radón/aislamiento & purificación , Estadística como AsuntoRESUMEN
Radon in indoor air is often measured using canisters of activated charcoal that function by adsorbing radon gas. The use of a diffusion barrier charcoal canister (DBCC) minimizes the effects of environmental humidity and extends the useful exposure time by several days. Many DBCC protocols model charcoal canisters as simple integrating detectors, which introduces errors due to the fact that radon uptake changes over the exposure period. Errors are compensated for by calculating a calibration factor that is nonlinear with respect to exposure time. This study involves the development and testing of an equilibrium-based model and corresponding measurement protocol that treats the charcoal canisters as a system coming into equilibrium with the surrounding radon environment. This model applies to both constant and temporally varying radon concentration situations, which was essential, as efforts are currently underway using a temporally varying radon chamber. It was found that the DBCCs equilibrate following the relationship E = (1 - e) where E is a measure of how close the DBCC is to equilibrium, t is exposure time, and q is the equilibration constant. This equilibration constant was empirically determined to be 0.019 h. The proposed model was tested in a blind test as well as compared with the currently accepted U.S. Environmental Protection Agency (U.S. EPA) model. Comparisons between the two methods showed a slight decrease in measurement error when using the equilibrium-based method as compared to the U.S. EPA method.
Asunto(s)
Contaminación del Aire Interior/análisis , Carbón Orgánico/química , Modelos Químicos , Monitoreo de Radiación/instrumentación , Radón/análisis , Radón/aislamiento & purificación , Ultrafiltración/instrumentación , Absorción , Simulación por Computador , Análisis de Falla de Equipo , Dosis de Radiación , Radón/química , Ultrafiltración/métodosRESUMEN
Ways of using different decision-aiding techniques for optimizing and evaluating radon remedial measures have been studied on a large set of data obtained from the remediation of 32 houses that had an original indoor radon level above 1000 Bq/m(3). Detailed information about radon concentrations before and after remediation, type of remedial measures and installation and operation costs were used as the input parameters for a comparison of costs and for determining the efficiencies, for a cost-benefit analysis and a cost-effectiveness analysis, in order to find out whether these criteria and techniques provide sufficient and relevant information for improving and optimizing remediation. Our study confirmed that the installation costs of remediation do not depend on the original indoor radon level, but on the technical state of the building. In addition, the study reveals that the efficiency of remediation does not depend on the installation costs. Cost-benefit analysis and cost-effectiveness analysis lead to the conclusion that remedial measures reducing the indoor radon concentration from values above 1000 Bq/m(3) are always acceptable and reasonable. On the other hand, these techniques can neither help the designer to choose the proper remedial measure nor provide information resulting in improved remediation.
Asunto(s)
Análisis Costo-Beneficio , Restauración y Remediación Ambiental/métodos , Radón/aislamiento & purificaciónRESUMEN
In view of environmental concern, sorption of radium on natural bentonite mineral (Aleppo, Syria) was investigated using a batch-type method. Data were expressed in terms of distribution coefficients. An attempt to increase the selectivity of bentonite for radium was made by preparing M-derivatives. Loss of mineral crystallinity in acidic media and the formation of a new phase, such as BaCO3, in Ba-derivative were evidenced by XRD characterizations. Of the cationic forms, Na-bentonite showed the highest affinity. Mechanisms of radium uptake were studied using M-derivatives and simulated radium solutions. The obtained results indicated that surface sorption/surface ion exchange were the predominant processes. The distinct sorption behaviour observed with the Ba-form was, possibly, a reflection of radium coprecipitation with barium carbonate. The competing order of macro components, likely present in waste streams, was investigated by studying different concentrations of the corresponding salt media. Sodium was found to be the weakest inhibitor. The performance of natural bentonite and the most selective forms, i.e. Ba- and Na-derivatives, to sorb radium from actual oil co-produced waters, collected form Der Ezzor Petroleum Company (DEZPC), was studied. This showed the influential effect ofpH compared with other parameters.
Asunto(s)
Bentonita/química , Residuos Industriales/prevención & control , Radón/aislamiento & purificación , Ultrafiltración/métodos , Contaminantes Radiactivos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Absorción , SiriaRESUMEN
In support of the implementation of the new Canadian radon guideline, a comprehensive review of radon mitigation techniques used in countries around the world was undertaken, with particular emphasis on North America and Europe that have climates and construction techniques similar to Canada. The results of this review are presented here as an aid to administrators of radon control programmes, companies offering radon testing and mitigation services and other concerned parties, both in Canada and elsewhere, who are facing issues of implementing a radon control strategy. A wide variety of radon mitigation strategies have been employed worldwide and all have achieved some success in reducing radon concentrations. Generally, active mitigation techniques involving physical alterations to a house (e.g. sub-slab depressurisation) are more effective in achieving a sustained and substantial radon reduction than passive techniques (e.g. improved ventilation or sealing of cracks). To a large extent, the choice of an optimal mitigation strategy will depend on the building type, soil conditions and climate. Radon levels should be measured at periodic intervals after remediation, perhaps once every 5 y, to ensure that concentrations continue to remain at acceptable levels.
Asunto(s)
Contaminantes Radiactivos del Aire/aislamiento & purificación , Materiales de Construcción , Exposición a Riesgos Ambientales/prevención & control , Protección Radiológica/instrumentación , Radón/aislamiento & purificación , Reología/métodos , Ultrafiltración/métodos , Diseño de Equipo , Protección Radiológica/métodosRESUMEN
Field measurements were conducted to assess the effects of an air cleaner on radon mitigation in a dwelling with a high radon concentration in Okinawa, Japan. The measurements included indoor radon concentration, individual radon progeny concentration, equilibrium equivalent concentration of radon (EECRn), unattached fraction, and size distribution of aerosol-attached radon progeny. These measurements were conducted in a 74 m(3) room with/without the use of an air cleaner. The results showed that the mean radon concentration during the measurement was quite high (301 Bq m(-3)). The operation of air cleaner decreased the radon progeny activity concentration, EECRn and equilibrium factor by 33%, 57% and 71%, respectively, whereas the unattached fraction increased by 174%. In addition, the activity concentration of attached radon progeny in the accumulation mode (50-2000 nm) was obviously deceased by 42%, when the air cleaner was operated. According to dosimetric calculations, the operation of air cleaner reduced the effective dose due to radon progeny by about 50%.
Asunto(s)
Aire Acondicionado/métodos , Contaminación del Aire Interior/prevención & control , Radón/aislamiento & purificación , Contaminantes Radiactivos del Aire , Vivienda , Japón , Dosis de RadiaciónRESUMEN
Radon concentration levels in a two-storey detached single-family dwelling in Northamptonshire, UK, were monitored continuously throughout a 5-week period during which active sub-slab depressurisation remediation measures were installed. Remediation of the property was accomplished successfully, with both the mean radon levels and the diurnal variability greatly reduced both upstairs and downstairs. Following remediation, upstairs and downstairs radon concentrations were 33% and 18% of their pre-remediation values respectively: the mean downstairs radon concentration was lower than that upstairs, with pre- and post-remediation values of the upstairs/downstairs concentration ratio, R(U/D), of 0.81 and 1.51 respectively. Cross-correlation between upstairs and downstairs radon concentration time-series indicates a time-lag of the order of 1 h or less, suggesting that diffusion of soil-derived radon from downstairs to upstairs either occurs within that time frame or forms a relatively insignificant contribution to the upstairs radon level. Cross-correlation between radon concentration time-series and the corresponding time-series for local atmospheric parameters demonstrated correlation between radon concentrations and internal/external pressure difference prior to remediation; this correlation disappears following remediation. Overall, these observations provide further evidence that radon concentration levels within a dwelling are not necessarily wholly determined by the effects of soil-gas advection, and further support the suggestion that, depending on the precise content of the building materials, upstairs radon levels, in particular, may be dominated by radon exhalation from the walls of the dwelling, especially in areas of low soil-gas radon.
Asunto(s)
Contaminantes Radiactivos del Aire/aislamiento & purificación , Contaminantes Radiactivos del Aire/toxicidad , Restauración y Remediación Ambiental/métodos , Radón/aislamiento & purificación , Radón/toxicidad , Contaminantes Radiactivos del Aire/análisis , Presión , Radón/análisis , Reino UnidoRESUMEN
This paper describes a new device and a method to determine the radon diffusion coefficient in damp-proof membranes developed in the Czech Republic. The main advantage of the device is that it enables tests to be carried out in all the known measuring modes used throughout Europe. Two recently developed computer programs are presented for the numerical modelling of the time-dependent radon transport through damp-proof membranes. According to this method, the radon diffusion coefficient is derived from the process of fitting the numerical solution to the measured curve of radon concentration in a receiver container. Numerical simulation and measured data are also compared. Reasons for disagreements between different methods and specific configurations of the measuring device are also discussed.
Asunto(s)
Análisis de Falla de Equipo/métodos , Membranas Artificiales , Protección Radiológica/instrumentación , Radiometría/métodos , Radón/química , Radón/aislamiento & purificación , República Checa , Difusión , Diseño de Equipo , Dosis de RadiaciónRESUMEN
The present paper shows methods to suppress radon emanation from artificial porous materials such as phosphorous fertiliser or diatomaceous earth with a small amount of radium. The basic concept of suppression is making the radon emanation mechanism 'null', which comes from the fact that recoil is the main mechanism of radon emanation at room temperature. Nullifying may be done through removal of water in the pore volume by heating and through removal of pores by melting or filling with sulphur. These radon emanation suppression methods were tried for phosphorous fertiliser and diatomaceous earth with a small amount of radium. The melting method was the most effective of all. Sustainability of these methods was also studied. The melting method was the most sustainable. The heating method was also sustainable for diatomaceous earth in spite of a long-term immersion in water.