179 research outputs found
Identifying the Presence of Natural Radionuclides in Ashlar Samples
Humans have always been exposed to different types of natural and cosmic radiation. At present we experience 83 % natural radiation, for example from granite marbles, building materials such as concrete, brick, granite, or drywall. However, although these are potential sources of radon, they are rarely the cause of a high level of pollution in a building.Ashlar is a material of volcanic origin comprising heterogeneous and solidified detrital pyroclastic materials such as rhyolite, sand, volcanic ash and pumice, among others. Chemically, ashlar is principally composed of elements such as sodium, magnesium, calcium, iron, aluminum, sulfur, and cobalt. In order to identify the presence of these elements in the ashlar, X-ray Fluorescence studies were carried out first, using modern XRD and XRF equipment, followed by quantitative analysis using a neutron activation technique, and finally, low-level gamma spectrometry to evaluate the presence of radioactive elements
Spatiotemporal distribution of δ¹³C-CO₂ in a shallow cave and its potential use as indicator of anthropic pressure
This study deals with the spatiotemporal dynamics of CO₂ and its isotopic composition (δ¹³C-CO₂) in the atmosphere of Altamira Cave (northern Spain) over two annual cycles. In general terms, the cavity shows two distinct ventilation modes, acting as a CO₂ reservoir from October to May (recharge stage), while actively exchanging gases with the outside atmosphere between July and September (discharge stage). In recharge mode, the in-cave air shows higher and relatively homogeneous CO₂ values (3332 ± 521 ppm) with lower δ¹³C-CO₂ ( 23.2 ± 0.4‰). In contrast, during the discharge stage, the CO₂ concentrations are lower and relatively more variable (1383 ± 435 ppm) and accompanied by higher δ¹³C-CO₂ (up to 12‰). This seasonal pattern is controlled by the distinct rates of exchange of air masses with the external atmosphere through the annual cycle, as well as by changes in the production of CO₂ in the soil and natural fluctuations in the concentration of dissolved inorganic carbon transported by drip water into the cave. In contrast to the interpretations of previous studies in Altamira Cave, no local air intakes into the deepest cave sections were flagged by our δ¹³C measurements. This finding is also supported by analyses of CO₂ and ²²²Rn in air, density of airborne particles and air temperature. In addition, preliminary experiments examining the visitor-produced disturbances on δ¹³C-CO₂ were conducted during the various cave ventilation stages to explore the potential use of this parameter as an indicator of anthropic pressure in caves. Our data show that visits (overall stay of 60-85 min; i.e., 4 people for 20 min) significantly affected δ¹³C-CO₂ (up to Δδ¹³C~-2‰) in the Polychrome Hall of Altamira Cave under conditions of low natural CO₂ (discharge stage), whereas it remained almost unaltered under circumstances of high CO₂ concentration (recharge stage). This demonstrates that δ¹³C-CO₂ is sensitive to perturbations produced by visitors during certain periods.The authors express warm thanks to the Altamira Cave Research Centre and Museum staff for their help and support during the sampling surveys in the cave. This research was founded by the Project entitled “Estudios analíticos para una propuesta de accesibilidad pública de la Cueva de Altamira” funded by the Spanish Ministry of Education, Culture and Sport (92522100). Sarah Steines is also thanked for revising the English
A new methodology for defining radon priority areas in spain
One of the requirements of EU-BSS (European Basic Safety Standards) is the design and implementation of a National Radon Action Plan in the member states. This should define, as accurately as possible, areas of risk for the presence of radon gas (222Rn) in homes and workplaces. The concept used by the Spanish Nuclear Safety Council (CSN), the body responsible for nuclear safety and radiation protection in Spain, to identify "radon priority areas" is that of radon potential. This paper establishes a different methodology from that used by the CSN, using the same study variables (indoor radon measurements, gamma radiation exposure data, and geological information) to prepare a radon potential map that improves the definition of the areas potentially exposed to radon in Spain. The main advantage of this methodology is that by using simple data processing the definition of these areas is improved. In addition, the application of this methodology can improve the delimitation of radon priority areas and can be applied within the cartographic system used by the European Commission-Joint Research Center (EC-JRC) in the representation of different environmental parameters
Generic utilities in chronic obstructive pulmonary disease patients stratified according to different staging systems.
Background To determine generic utilities for Spanish chronic obstructive pulmonary disease (COPD) patients stratified by different classifications: GOLD 2007, GOLD 2013, GesEPOC 2012 and BODEx index. Methods Multicentre, observational, cross-sectional study. Patients were aged ≥40 years, with spirometrically confirmed COPD. Utility values were derived from EQ-5D-3 L. Means, standard deviations (SD), medians and interquartile ranges (IQR) were computed based on the different classifications. Differences in median utilities between groups were assessed by non-parametric tests. Results 346 patients were included, of which 85.5% were male with a mean age of 67.9 (SD = 9.7) years and a mean duration of COPD of 7.6 (SD = 5.8) years; 80.3% were ex-smokers and the mean smoking history was 54.2 (SD = 33.2) pack-years. Median utilities (IQR) by GOLD 2007 were 0.87 (0.22) for moderate; 0.80 (0.26) for severe and 0.67 (0.42) for very-severe patients (p 2: 0.89 (0.20); group 34: 0.80 (0.27); group 56: 0.67 (0.29); group 79: 0.41 (0.31). All comparisons were significant (p 4 and 56. Conclusion Irrespective of the classification used utilities were associated to disease severity. Some clinical phenotypes were associated with worse utilities, probably related to a higher frequency of exacerbations. GOLD 2007 guidelines and BODEx index better discriminated patients with a worse health status than GOLD 2013 guidelines, while GOLD 2013 guidelines were better able to identify a smaller group of patients with the best health
Specific Immunotherapy Can Be A Useful Treatment in Seasonal Pollen Induced Esophagitis
[EN] Although pollen allergy is very common in patients with eosinophilic esophagitis (EoE), it is doubtful that pollen is an etiological agent to consider.
We selected 255 patients suffered from esophagitis with seasonal exacerbation, and performed a real life study on the efficacy of immunotherapy with the detected pollen and avoidance of food, if was also detected. Allergens involved in EoE were identified by prick, specific IgE and molecular analysis: component resolved diagnosis (CRD) by microarrays.
Microscopic examination of esophageal biopsies of patients with EoE were made to verify the presence of callose (polysaccharide abundant in the polinic tubes during germination, but absent in animal tissues) in the esophagus. Endoscopy and biopsy were performed ever six months of treatment. Esophageal mucosal sections were analyzed by scanning electron microscope Immunotherapy guided by molecular analysis and biopsy study was useful to decide the treatment (avoidance or targeted immunotherapy). This treatment allowed us a more reasonable restriction of food in the diet and specific immunotherapy aimed at the suspected allergens responsible for the disease. After immunotherapy, 188 (74%) patients were discharged whit negative biopsy, no symptoms, no medication, without relapse. Specific molecular guided immunotherapy can be a useful treatment in seasonal pollen induced esophagitisS
Investigation of the performance of various low-cost radon monitors under variable environmental conditions
A comparison of low-cost radon monitors was conducted at the Laboratory of Natural Radiation (LNR). The monitors we evaluated were EcoQube, RadonEye, RadonEye Plus2, Spirit, ViewPlus, ViewRadon and WavePlus. An AlphaGUARD monitor calibrated at the Laboratory of Environmental Radioactivity of the University of Cantabria (LaRUC), accredited for testing and calibration according to ISO/IEC 17025, provided the reference value of radon concentration. The temporal stability of the monitors was studied, obtaining a percentage of missing records ranged from 1% to 19% of the data. The main technical characteristics studied were temporal stability, measurement ranges, accuracy, correlation and response time. The main results show that the measurement ranges align with those specified by their manufacturers, with percentage differences with respect to the reference monitor of between 5% and 16%. The diversity found for response time is remarkable, with values ranging from 1 to 15 h, with Pearson correlation factors between 0.63 and 0.90.Funding: This research received no external funding.
Acknowledgments: Authors would like to express their gratitude to the National Uranium Company of Spain (ENUSA Industrias Avanzadas) for the collaboration given during all these years. The cooperation of the staff of Saelices el Chico center was essential to carry out this research
Intercomparison of Indoor Radon Measurements Under Field Conditions In the Framework of MetroRADON European Project
Interlaboratory comparisons are a basic part of the regular quality controls of laboratories to warranty the adequate performance of test and measurements. The exercise presented in this article is the comparison of indoor radon gas measurements under field conditions performed with passive detectors and active monitors carried out in the Laboratory of Natural Radiation (LNR). The aim is to provide a direct comparison between different methodologies and to identify physical reasons for possible inconsistencies, particularly related to sampling and measurement techniques. The variation of radon concentration during the comparison showed a big range of values, with levels from approximately 0.5 to 30 kBq/m3. The reference values for the two exposure periods have been derived from a weighted average of participants' results applying an iterative algorithm. The indexes used to analyze the participants' results were the relative percentage difference D(%), the Zeta score ( ? ), and the z-score ( z ). Over 80% of the results for radon in air exposure are within the interval defined by the reference value and 20% and 10% for the first and the second exposure, respectively. Most deviations were detected with the overestimating of the exposure using passive detectors due to the related degassing time of detector holder materials.This research was funded by the European Metrology Programme for Innovation and Research (EMPIR), JRP‐Contract 16ENV10 MetroRADON (http://www.euramet.org). The EMPIR initiative is co‐funded by the European Union’s Horizon 2020 research and innovation programme and the EMPIR Participating States
The Laboratory of Natural Radiation (LNR) - a place to test radon instruments under variable conditions of radon concentration and climatic variables
The publication of the new European Union Basic Safety Standards represents a remarkable milestone
in the fi eld of radiological protection in terms of adding radon exposure to this framework. Therefore, the
coming years will bring the need to measure radon not only in the workplaces but also in the living spaces as
a direct outcome of the application of the new EU Directive. So, the importance of having reliable instruments
is evident and interlaboratory exercises are becoming more and more popular. However, most of them are carried
out under constant conditions of meteorological variables. We present in this paper a facility to broaden the
interlaboratory comparisons further by adding the study of radon exposures under real conditions of changes in
climatic parameters. In addition, the facility has the possibility to verify the response of radon monitors when
the radon concentration changes several orders of magnitude in a short period of time. Our work shows some
results of one of the interlaboratory exercises carried out in the premises, where the radon levels were rather
homogeneous in the testing room
Methodological Approaches to Radon in Water Measurements: Comparative Experiences between Romania and Spain
The EC Directive 2013/51/EURATOM of 22 October 2013 represents the first time that a radon limit for drinking water has been proposed. Transposition of this Directive into Spanish legislation was by means of the recent RD 314/2016 which sets a limit value of 500 Bq l?1 for radon (222Rn) in water for human consumption while that in Romanian legislation the Law 301/2015 provides a limit value of 100 Bq l-1 for 222Rn concentration in water for human consumption as well as a total effective dose of 0.1 mSv y-1 from all radionuclides present in water (same dose value established by Spanish law).
For several years, both in Romania and in Spain, there have been campaigns to measure the concentration of 222Rn in waters of different origins in order to determine the possible exposure of the population through this irradiation path, and also to use the presence of radon dissolved in water as a source of indoor radon in thermal spa facilities, and also as a tracer of dynamic processes (C. Sainy et al., Sci. Tot. Envir. 543, 460 (2016); 1).
In this article, an assessment of the results from measurement campaigns in both countries will be presented and compared. In addition, the different measurement techniques used will be described, and the description of an intercomparison exercise on radon measurement in water organized by the Environmental Radioactivity Laboratory of the University of Cantabria (LaRUC) will be presented, in order to evaluate the quality of the performance of the techniques used.This work was partially supported by the project ID P_37_229, Contract No. 22/01.09.2016, with the title Smart Systems for Public Safety through Control and Mitigation of Residential Radon linked with Energy Efficiency Optimization of Buildings in Romanian Major Urban Agglomerations SMART-RAD-EN of the POC Programme
Variations in radon dosimetry under different assessment approaches in the Altamira Cave
The atmosphere of caves is a special environment where it is necessary to take
into account some particular characteristics when assessing the radon dose.
The equilibrium factor (F) between radon and its progeny, and especially its
unattached fraction ( fp), is a key parameter in radon dose evaluation. In order
to consider the specific features of the atmosphere in the Altamira Cave, the
radon and particle concentrations have been measured. The mean annual radon
concentration inside the cave over the period 2013?2019 is around
3500 Bq m?3 with a standard deviation of 1833 Bq m?3 and this exhibits
seasonal variations. This value surpasses all international (WHO, IAEA,
ICRP) upper action and reference levels (occupational and non-occupational).
Dose rate levels expressed in ?Sv h?1 were estimated for four different
equilibrium scenarios between radon and its progeny 218Po, 214Pb, 214Bi and
214Po. The most recent dose conversion factors have been used and the
contribution made to the dose by the unattached fraction of radon progeny fp
has been also assessed from the particle concentration. The results suggest that
the mean annual dose levels show variations of up to 500% due to the range of
F and the fp considered in this study. Given the high radon concentrations
usually found in show caves, the best way to reduce this variability and its associated uncertainty in dose assessment is to conduct specific studies aimed
at determining both F and fp.This work was supported by the Ministry of Education, Culture and Sport of Spain (MECD) (grant number J180052) under the Project ‘Servicio de control y seguimiento de las condiciones ambientales y del biodeterioro de la Cueva de Altamira’, and The Cantabrian International Institute for Prehistoric Research (IIIPC)
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