Bibliografia
Informes de la construcción,
01/2022, Letnik:
74, Številka:
568
Journal Article
Recenzirano
Odprti dostop
Este gas aparece en la naturaleza por la desintegración espontanea del radio, elemento que está presente en buena parte de la corteza terrestre. Esta monografía está dedicada principalmente al ...desarrollo técnico de la misma, considerada de mayor efectividad, pero también de mayor complejidad en su diseño y cálculo. Se fundamenta en la generación de un campo de presiones negativo en la interfase entre el terreno y la solera o forjado, con el fin de facilitar el transporte del gas hacia el punto o puntos de extracción, atenuando así el flujo advectivo hacia el interior del edificio. En el sector, es conocida la dificultad que entraña la aplicación en edificios ya construidos, básicamente por el desconocimiento de buena parte de los aspectos constructivos ocultos como cimentaciones, juntas, fisuras, permeabilidades de terreno, sustratos bajo la solera, etc. La técnica de despresurización bajo solera es muy sensible a todos estos aspectos y, sin un conocimiento de ellos y de los fundamentos de la técnica, es fácil fallar en su aplicación y no lograr las reducciones esperadas. Se explica su fundamento científico-técnico, las bases de su diseño y cálculo, las variantes en su aplicación y las técnicas de diagnóstico que ayudan a lograr una mayor efectividad. Este trabajo se basa en los conocimientos adquiridos en el desarrollo de varios proyectos de investigación: * RADON FLOW- Estudio de agregados y solados porosos como propuestas correctoras de radón en edificios basadas en técnicas de despresurización (PID2019-109898RB-I00). * RADON CERO-Optimización de soluciones constructivas frente a la inmisión de gas radón en edificios y desarrollo de metodologías de diseño de soluciones (n.º Ref. También se ha utilizado material preveniente de resultados de contratos de investigación donde se han puesto en práctica técnicas desarrolladas en los proyectos citados.
Among the physical pollutants affecting indoor air, the radioactive gas radon may turn out to be the most hazardous. Health effects related to radon exposure have been investigated for several ...decades, providing major scientific evidence to conclude that chronic exposures can cause lung cancer. Additionally, an association with other diseases, such as leukemia and cancers of the extra-thoracic airways, has been advanced. The implementation of a strategy to reduce the exposure of the population and minimize the health risk, according to the European Directive 59/2013/Euratom on ionizing radiations, is a new challenge in public health management. Starting from an understanding of the general state-of-the-art, a critical analysis of existing approaches has been conducted, identifying strengths and weaknesses. Then, a strategy for assessing the radon exposure of the general population, in a new comprehensive way, is proposed. It identifies three main areas of intervention and provides a list of hazard indicators and operative solutions to control human exposure. The strategy has been conceived to provide a supporting tool to authorities in the introduction of effective measures to assess population health risks due to radon exposure.
Persönliches
Bauingenieurin Lamia Messari‐Becker in den Club of Rome berufen
Aktuell
DIBt ist Behörde für Schutz vor Radioaktivität in Bauprodukten
BfS‐Broschüre zu Radon‐Messungen an Arbeitsplätzen
...Neues Merkblatt „Mikrobiologischer Bewuchs auf Fassaden – Algen und Pilze”
BBSR ruft Netzwerk Nachhaltige Unterrichtsgebäude ins Leben
Schullüftung mit „Weltraumtechnik fürs Klassenzimmer”
ift‐Richtlinie FE‐16/2 Einsatzempfehlungen für Fenster in Schulbauten
Filter‐Upgrade zur Minderung des Infektionsrisikos
Geogenic radon potential (GRP) is traditionally used for mapping radon-prone areas. However, this has challenges in the accurate assessment of radon risk because of limitations such as oversimplified ...soil measurements and lack of geological profiles. This study presents predictive geogenic radon potential (P-GRP), integrating geological characterization and advanced modeling for the emanation and transport of radon in the subsurface environment. Seoul, South Korea, was selected as the research area for the evaluation of hazards using P-GRP, while subway station A was selected for the assessment of indoor health risks. The geology was characterized by the layers of bedrock and soil using uranium contents and porosity. The emanation of radon was modeled considering the radioactive decay chain of uranium and the pore structures. The vertical transport of radon was modeled considering the porosity variation within geological media, which was used for the calculation of P-GRP. Without loss of continuity, the P-GRP map was constructed by calculating P-GRP at a specific depth over the Seoul area. The calculation of P-GRP in the case of subway station A demonstrates that the radon concentration in the bedrock at the platform depth was expected to be 382 million Bqm−3. The indoor radon risk was calculated using the P-GRP by coupling the vapor intrusion process. This presented a high cancer risk for the employees as well as commuters. The P-GRP map of Seoul demonstrated higher hazards in granite zones compared to banded gneiss zones. These results have demonstrated that the P-GRP could be a novel and promising approach for assessing hazard and risk by geogenic radon during subsurface development.
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•A novel approach for assessing hazard and risk by radon in subsurface development•Utilization of advanced 3D geological profiling and vertical transport dynamics•Scenario-driven insights facilitate effective risk mitigation strategies•Expanded assessment of radon hazard across various depths•Development of scalable solutions for urban radon risk management
As an inert radioactive gas,
222
Rn could be easily transported to the atmosphere via emanation, migration, or exhalation. Research measurements pointed out that
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Rn activity concentration changes ...during the winter and summer months, as well as during wet and dry season periods. Changes in radon concentration can affect the atmospheric electric field. At the boundary layer near the ground, short-lived daughters of
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Rn can be used as natural tracers in the atmosphere. In this work, factors controlling
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Rn pathways in the environment and its levels in soil gas and outdoor air are summarized.
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Rn has a short half-life of 3.82 days, but the dose rate due to radon and its radioactive progeny could be significant to the living beings. Epidemiological studies on humans pointed out that up to 14% of lung cancers are induced by exposure to low and moderate concentrations of radon. Animals that breed in ground holes have been exposed to the higher doses due to radiation present in soil air. During the years, different dose-effect models are developed for risk assessment on human and non-human biota. In this work are reviewed research results of
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Rn exposure of human and non-human biota.
In the near future, research on new materials for radon barriers can be expected to rise in order to meet a greater demand of radon mitigation solutions because of the increasingly lower radon levels ...that the EU legislation aims to. Such research would need a method for the determination of the radon diffusion coefficient and this paper presents an inexpensive method for that purpose, using affordable radon detectors and a simple experimental setup that does not require any tubing or any pumping. Besides the use of two Electronic Integration Devices as radon detectors, the experimental setup used in our method consists only in a two-chamber container made of steel and a small-sized radon source, which was produced in our lab using a 226Ra solution. The radon diffusion coefficient is determined by measuring radon levels in both chambers of the container, which are separated by a membrane made of the material whose radon diffusion coefficient is to be determined. Radon diffuses from a source chamber to a receiver chamber trough the membrane, being the amount of radon that has passed through and the rate at which it has done so the key parameters in the calculation of the radon diffusion coefficient. Our method can handily measure materials with a radon diffusion coefficient above or equal to 10-11 m2 s-1 or, provided that the sample is thin enough, verify that the coefficient is lower than 10-12 m2 s-1. Its precision is good enough to provide radon coefficient diffusion values with a good repeatability as the RSD is as low as a 35% for materials in which the coefficient is in the order of 10-11 m2 s-1. This means that our method is valid for screening materials for radon barriers and checking their compliance with technical specifications.
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•New and inexpensive method for the determination of the radon diffusion coefficient, using a simple experimental setup.•Two Electronic Integration Devices are used as radon detectors inside an airtight container, with a small-sized radon source.•This method can measure materials with low radon diffusion coefficients, allowing the screening materials for radon barriers.
Indoor radon (
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Rn) measurements were carried out using solid state nuclear track detectors (SSNTD) in some dwellings from southwestern Nigeria. This was aimed at statistically assessing influence ...of building characteristics on the measured radon and estimating excess lifetime cancer risks (ELCR). The measured radon concentrations followed lognormal distribution and were significantly influenced by some building properties. The arithmetic mean (1.60 mSv) of annual effective doses (AEDs) due to indoor radon was observed to be higher than the world average level (1.15 mSv) but less than lower limit (3 mSv) of International Commission on Radiological Protection (ICRP). The evaluated excess lifetime cancer risk ranged from 1.5 to 28.1 (MPy)
−1
with an average value of 6.3 (MPy)
−1
, indicating that after exposure to indoor radon for 70 years, 6 people in every 1000 are likely to suffer the risk of developing lung cancer. Adequate ventilation systems were recommended for houses with high level of radon to avoid unnecessary exposure to radon. However, the investigated data would form important component of the database required to set up guidelines and policy of controlling radon at home.
Indoor radon exposure is raising concerns due to its impact on health, namely its known relationship with lung cancer. Consequently, there is an urgent need to understand the risk factors associated ...with radon exposure, and how this can be harmful to the health of exposed populations. This article presents a comprehensive review of studies indicating a correlation between indoor radon exposure and the higher probability of occurrence of health problems in exposed populations. The analyzed studies statistically justify this correlation between exposure to indoor radon and the incidence of lung diseases in regions where concentrations are particularly high. However, some studies also showed that even in situations where indoor radon concentrations are lower, can be found a tendency, albeit smaller, for the occurrence of negative impacts on lung cancer incidence. Lastly, regarding risk remediation, an analysis has been conducted and presented in two core perspectives: (i) focusing on the identification and application of corrective measures in pre-existing buildings, and (ii) focusing on the implementation of preventive measures during the project design and before construction, both focusing on mitigating negative impacts of indoor radon exposure on the health of populations.
Naturally occurring radon and its short lived progeny are the second leading cause of lung cancer after smoking, and the main risk factor for non-smokers. The radon progeny, mainly Polonium-218 (
Po) ...and Polonium-214 (
Po), are responsible for the highest dose deposition in the bronchial epithelium via alpha-decay. These alpha-particles release a large amount of energy over a short penetration range, which results in severe and complex DNA damage. In order to unravel the underlying biological mechanisms which are triggered by this complex DNA damage and eventually give rise to carcinogenesis, in vitro radiobiology experiments on mammalian cells have been performed using radon exposure setups, or radon analogues, which mimic alpha-particle exposure. This review provides an overview of the different experimental setups, which have been developed and used over the past decades for in vitro radon experiments. In order to guarantee reliable results, the design and dosimetry of these setups require careful consideration, which will be emphasized in this work. Results of these in vitro experiments, particularly on bronchial epithelial cells, can provide valuable information on biomarkers, which can assist to identify exposures, as well as to study the effects of localized high dose depositions and the heterogeneous dose distribution of radon.
Radon is a naturally occurring gas, classified as a Class 1 human carcinogen, being the second most significant cause of lung cancer after tobacco smoking. A robust spatial definition of radon ...distribution in the built environment is therefore essential for understanding the relationship between radon exposure and its adverse health effects on the general population. Using Ireland as a case study, we present a methodology to estimate an average indoor radon concentration and calculate the expected radon-related lung cancer incidence. We use this approach to define Radon Priority Areas at the administrative level of Electoral Divisions (EDs).
Geostatistical methods were applied to a data set of almost 32,000 indoor radon measurements, sampled in Ireland between 1992 and 2013. Average indoor radon concentrations by ED range from 21 to 338 Bq m−3, corresponding to an effective dose ranging from 0.8 to 13.3 mSv y−1 respectively. Radon-related lung cancer incidence by ED was calculated using a dose-effect model giving between 15 and 239 cases per million people per year, depending on the ED. Based on these calculations, together with the population density, we estimate that of the approximately 2,300 lung cancer cases currently diagnosed in Ireland annually, about 280 may be directly linked to radon exposure. This figure does not account for the synergistic effect of radon exposure with other factors (e.g. tobacco smoking), so likely represents a minimum estimate. Our approach spatially defines areas with the expected highest incidence of radon-related lung cancer, even though indoor radon concentrations for these areas may be moderate or low. We therefore recommend that both indoor radon concentration and population density by small area are considered when establishing national radon action plans.
•32,000 indoor radon measurements were used to estimate the radon exposure in Ireland.•An average indoor radon concentration at administrative level was calculated.•Approximately 280 of the 2300 lung cancer incidences per year may be linked to radon.•Radon-related lung cancer is included in the definition of Radon Priority Areas.
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