Assessment of environmental radiological impact in former metallic mines in Extremadura (Spain): A case study.

Metal mining in the Extremadura region was very important in the 19th and 20th centuries. However, due to different reasons the great majority of mines ceased operations, leading to plenty of abandoned mining sites, most of them with on-site waste dumps. Although metal extraction is not radioactive per se, it is considered a NORM activity. In this study, three former mining sites, in which Pb-V-Zn-Ag, Pb-Ag, and Pb-Zn were extracted, were selected to assess the radiological impact on the population and the environment. The external γ exposure was estimated by determining the effective dose and elaborating isodose maps of the sites. The presence of the mining sites increased up to 0.41 mSv/y the effective dose over the surrounding background, which is below the reference value of 1 mSv/y. In only one mining site, the uranium and radium activity concentration of waste dumps were higher than the surrounding soil. The soil to plant (wild grass) transfer factors were similar to other reported values without the influence of NORM activities. So, no enhanced transfer of radionuclides was observed. The radiological impact on the environment was assessed by the risk to non-human biota using the tiered approach developed in ERICA Tool. The sum of the risk quotients of all considered radionuclides in the most conservative Tier 1 was below 1. Total dose rates for several terrestrial Reference Animal and Plants (RAPs) were estimated using Tier 3, obtaining values below 40 µGy/h. Therefore, the impact on non-human biota can be considered as negligible.

Can stable elements (Cs and Sr) be used as proxies for the estimation of radionuclide soil-plant transfer factors?

Transfer parameters are key inputs for modeling radionuclide transfer in the environment and estimating risk to humans and wildlife. However, there are no data for many radionuclide-foodstuff/wildlife species combinations. The use of parameters derived from stable element data when data for radionuclides are lacking is increasingly common. But, do radionuclides and stable elements behave in a sufficiently similar way in the environment? To answer this question, at least for soil to plant transfer, sampling was conducted in four different countries (England, Kazakhstan, Spain and Ukraine) affected by different anthropogenic radionuclide source terms (in chronological order: global fallout, Semipalatinsk Test Site, the 1957 Windscale accident and the 1986 Chernobyl accident) together with a bibliographical review. Soil to grass transfer parameters (ratio between dry matter concentrations in plant and soil), Fv, for 137Cs and 90Sr were significantly higher than those for stable elements, suggesting that the use of the latter could lead to underestimating radionuclide concentrations in plant samples Transfer parameters for 137Cs and stable Cs were linearly correlated, with a slope of 1.54. No such correlation was observed for 90Sr and stable Sr, the mean value of the 90Sr:Sr ratio was 35 ranging (0.33-126); few data were available for the Sr comparison. The use of radionuclide transfer parameters, whenever possible, is recommended over derivation from stable element concentrations. However, we acknowledge that for many radionuclides there will be few or no radionuclide data from environmental studies. From analyses of the data collated there is evidence of a decreasing trend in the Fv(137Cs)/Fv(Cs) ratio with time from the Chernobyl accident.

Comparison of the Effects of Endotracheal Intubation of Wistar Rats Using the Conventional Technique vs. a New Modified Technique Using a 3D Mouth-Piece.

AIMS: Endotracheal intubation in rats is challenging due to the difficult anatomical characteristics of the airway. The success rate at first attempt is low and airway damage is a common complication. We aimed to compare and evaluate the conventional intubation method with a modified procedure using an inclined plate, headlamp (700-Lumen), and 3D mouth-piece designed with a 20° curvature. Both techniques were conducted by laboratory personnel with and without previous experience in airway management of laboratory rats. MATERIAL AND METHODS: In this study, we used 36 Wistar rats of both genders. Three groups of laboratory personnel (anesthesiologists, medical students, and laboratory technicians) performed both endotracheal intubation techniques, i.e., blind intubation at supine position and endotracheal intubation at 70° supine position with a 3D mouth-piece and direct illumination of the glottis. RESULTS: The modified technique had a significantly higher success rate and shorter procedure duration. Moreover, there was no significant difference in the procedure duration between personnel with and without previous training in airway management. CONCLUSION: Previous knowledge and experience in airway management are required when performing conventional endotracheal intubation; moreover, its success rate is low. Contrastingly, using proper instruments and the 3D mouth-piece facilitated easier and quicker airway management regardless of previous experience.

Modification of natural radionuclide uptake by wheat using a NORM by-product as soil amendment.

Drinking Water Treatment Plants (DWTPs) can be optimised for removal of natural radionuclides, thus meeting EU legislation. Removed radionuclides (234,238U, 226Ra and 210Po) go into sludges. What would happen if these sludges were used in agriculture? Wheat plantlets were cultivated in original and sludge-amended soils under laboratory controlled conditions. Soil-to plant transfer was significantly increased in factors ranging 1.2-3.7, 2.0-5.6, and 1.6-2.4 for 234,238U, 226Ra and 210Po, respectively. The additional input was preferentially accumulated in roots.

Undetectable viral RNA in oocytes from SARS-CoV-2 positive women.

A central concern for the safe provision of ART during the current coronavirus disease 2019 (COVID-19) pandemic is the possibility of vertical transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through gametes and preimplantation embryos. Unfortunately, data on SARS-CoV-2 viral presence in oocytes of infected individuals are not available to date. We describe the case of two women who underwent controlled ovarian stimulation and tested positive to SARS-CoV-2 infection by PCR on the day of oocyte collection. The viral RNA for gene N was undetectable in all the oocytes analyzed from the two women.

Transfer of radionuclides and stable elements to foodstuffs in Mediterranean ecosystems.

Adequate radiological protection requires the quantification of radionuclide transfer to the human food chain, which is essential for the estimation of ingestion doses. Transfer parameters are key inputs for the development of radioecological models and decision support systems. There are many literature compilations of these parameters, however, most of values were calculated in temperate climates, and data for Mediterranean ecosystems are scarce. In this study, transfer factors to foodstuffs collected in Mediterranean ecosystems, in Spain, were compared to reported values for temperate climate. Foodstuff included cereals, meat (beef, lamb and pork), dairy products (milk, cheese yogurt, and kefir), and also typical products of Mediterranean diet, such as olives, olive oil, grapes and wine. Radioactive (137Cs, 226,228Ra and 40 K) and stable elements (Cs, Sr, K, Na, Ca, Mg, P, Pb, U and Th) were measured to enable the calculation of transfer factors. As a consequence, data for transfer factors in Mediterranean systems were increased by about 120 and 200 values for plant and animal products, respectively. Due to the low level radiocaesium concentration in Spanish ecosystems, transfer factors for this radioisotope were largely 'less than' values. Therefore, stable Cs and Sr transfer factors were used as proxy for comparison with temperate values.

Can models based on phylogeny be used to predict radionuclide activity concentrations in crops?

The modelling of transfer of radionuclides from soils to plants generally relies upon empirical soil-plant concentration ratios. Concentration ratios are often highly uncertain and are not available for many plant-radionuclide combinations. A number of papers published over the last 20 years have suggested that phylogenetic models could be used to make predictions of the radionuclide transfer to plants. Such a modelling approach would have the advantage that site factors (typically related to soils) are taken into account. For the first time we have compared predictions of Cs and Sr transfer to a range of crops grown on different soils. Predictions for both elements were generally acceptable (within an order of magnitude of observed data) but Sr concentrations were over predicted in fruits and tubers. This over prediction of Sr concentrations is likely to be because the phylogenetic models were fitted to data for green shoots. We conclude that phylogenetic models offer a number of advantages, but that they must be validated and, in future, parametrisation datasets need to include data on concentrations in edible plant parts and not just green shoots.

Relationship between indoor ambient dose equivalent rates and the architectural style of standalone houses in locations with high naturally occurring radionuclide soil concentrations.

There have been numerous studies relating house construction materials with the indoor gamma dose rate mainly coming from natural radionuclide activities. The relationship between the outdoor gamma dose rate and the soil's naturally occurring radionuclide content is well documented. Few studies, however, have investigated the historical evolution of indoor gamma dose levels due to the principal materials used in house construction in geographical areas where outdoor natural radiation levels are significant. The present work was carried out in an area of Spain with high outdoor gamma dose levels (on average, 0.267 µSv h-1) due to the natural radioactive characteristics of its soils, considering a great variety of standalone houses built from the beginning of the 18th century until today with different styles, architectural techniques, and materials in their construction. The measured ambient dose equivalent rates in thgese houses decreased the more recent the date of their construction was. In conclusion, today's architectural style for housing, which uses materials of practically universal origin, not only attenuates part of the irradiation due to the composition of a location's soils but also contributes less to the indoor gamma dose rate due to the relatively low naturally occurring radionuclide concentration of modern building materials.

Comparative Study of Capillary Filtration Coefficient (Kfc) Determination by a Manual and Automatic Perfusion System. Step by Step Technique Review.

The purpose of calculating the capillary filtration coefficient is to experimentally evaluate edema formation in models of pulmonary ischemia-reperfusion injury. For many years, the obtaining of this coefficient implies a series of manual maneuvers during ex-vivo reperfusion of pulmonary arterial pressure, venous pressure and weight, as well as the calculation of the Kfc formula. Through automation, the calculation of capillary filtration coefficient could be easier and more efficient. To describe an automatic method designed in our laboratory to calculating the capillary filtration coefficient and compare with traditional determination of capillary filtration coefficient as gold standard method. An automatic three valve perfusion system was constructed, commanded by a mastery module connected to a graphical user interface. To test its accuracy, cardiopulmonary blocks of Wistar rats were harvested and distributed in manual (n=8) and automated (n=8) capillary filtration coefficient determination groups. Physiological parameters as pulmonary arterial pressure, pulmonary venous pressure, weight and capillary filtration coefficient were obtained. Results: Capillary filtration coefficient, pulmonary arterial pressure, venous arterial pressure shown no statistical significance difference between the groups. The automated perfusion system for obtaining Kfc was standardized and validated, giving reliable results without biases and making the process more efficient in terms of time and personal staff.

Removal of radium in a working drinking water treatment plant: Radiological hazard assessment and waste management.

Occurrence of radium in drinking water may pose a radiological hazard. It is one of the most radiotoxic radionuclides and a major contributor to the Indicative Dose (ID), regulated parameter in UE. Its removal at Drinking Water Treatment Plants (DWTPs) can be considered a preventive action, as it cannot reach the final consumer nor be accumulated in distribution pipes. A filtration system based on greensand designed for radium removal was tested in an actual DWTP. Removal effectiveness depended on the spatial velocity water passed through the filter, range 65-100%. The lower the spatial velocity, the greater contact time, and the longer high removal percentages were achieved. The radium removed from the water was mainly associated to easily reducible fraction in greensand. So radium accumulation in the filter may pose a radiological hazard for the workers in the DWTP. Dose rate was assessed in the worst case scenario for this case study, being about 0.22 mSv/y, significantly lower than reference value 1 mSv/y. Radium accumulated in the greensand filter can be extracted in order to ease waste management, and subsequently, the filtration system can be regenerated showing similar capacity to extract radium as a new one.

Seasonal evolution of 7,10Be and 22Na in the near surface atmosphere of Cáceres (Spain).

Cosmogenic radionuclides provide information about air masses exchanges between stratosphere and troposphere. The 7Be concentration in aerosols usually shows a seasonal variability, depending also of the climatic conditions. There are, however, fewer data available of the behavior of other cosmogenic radionuclides, such as 10Be and 22Na. In this work about 7 years of aerosols collected in Cáceres (Spain) were analyzed. The 7Be concentration was higher than 22Na and 10Be, being the 22Na/7Be and 10Be/7Be ratios (1.16 ±â€¯0.02)·10-4 and (1.5 ±â€¯0.3)·10-4 respectively. For the 22Na/7Be, a seasonal variation was observed, being higher in spring/summer. Seasonal variation of 7Be and 22Na were explained using a model taking into account local values of the solar radiation, rainfall and dry deposition. The effective residence time for 7Be and 22Na were (9.9 ±â€¯1.0) and (11.3 ±â€¯1.4) d respectively. Both 7Be and 22Na seemed to decrease with increasing number of sunspots, although it was not statistically significant probably due to the low solar activity reported in the analyzed period.

[Description of Influenza B in seasonal epidemics in Spain]. / Descripción de la gripe B en las epidemias estacionales de España.

OBJECTIVE: Seasonal influenza epidemics are a major public health concern. They are caused by the influenza A and B viruses; although the A virus is more prominent, influenza B virus infection causes a disease with similar characteristics. There are two phylogenetically distinct influenza B lineages (B/Victoria and B/Yamagata), only one of which is present in the trivalent vaccine formulated each season. METHODS: Epidemiological data from the Spanish Influenza Surveillance System for 2007 to 2017 were reviewed to establish the relative proportion of each type of virus and the characterization of the B lineages in relation to the composition of the trivalent vaccine. RESULTS: The median proportion of B (2007-2017) was 27.2% (0.7%-74.8%) vs. 16.3% (0.4%-98.6%) for A-H3 and 44.2% (0.1%-98.0%) for pandemic A-H1N1 (20092017). The B lineages co-circulated in 8/10 seasons and there was mismatch with the B vaccine strain in 4/10 seasons. The B virus was dominant in 2007/08 and 2012/13 throughout Spain. There was a combination of dominance/codominance of influenza B and mismatch with the vaccine lineage in at least one third of epidemic seasons reviewed. CONCLUSIONS: Epidemiological information on influenza B has been less compiled in comparison with data on the A virus. Influenza virus type B is responsible for a significant number of cases in almost all seasons. The predominant B lineage in each season is unpredictable, affecting the protection conferred by the seasonal vaccine. Spanish epidemiological data support the rationale for a quadrivalent vaccine with both B virus lineages similarly to data from other settings.

The birthweight toll of mining pollution: evidence from the most contaminated mine site in the Andean region.

OBJECTIVE: To assess the effect of mining pollution on birthweight. DESIGN: A retrospective before-and-after study with an untreated comparison group. SETTING: La Oroya, a mining town in the Peruvian Andes, considered the most contaminated town in the Andean region. POPULATION: All pregnant women who delivered in the social security healthcare system in years 2005, 2006, 2008 and 2009. A total of 214 983 births records were used, 957 from La Oroya and 214 026 from the rest of the country. METHODS: A difference-in-difference estimation is used to assess the effect of mining pollution on birthweight before and after two business policy changes: a partial environmental improvement and a subsequent closure of smelter operations in La Oroya. Birthweight was compared with a group not affected by the environmental changes in La Oroya. MAIN OUTCOME MEASURES: Birthweight in grams. RESULTS: A steep reduction in mining pollution due to the closure of smelter operations in La Oroya showed an increased birthweight of 71.6 g after controlling for socio-economic and medical characteristics. None of the environmental improvements prior to the closure had a statistically significant effect on birthweight. CONCLUSIONS: Mining pollution in La Oroya had a negative impact on birthweight. Partial environmental improvements were not enough to improve birthweight. Only after the closure of all mining and smelter operations in La Oroya was a significant gain in birthweight shown. TWEETABLE ABSTRACT: The closure of the most contaminated mine site in the Andean region increased birthweight by 72 g.

Semiclassical transport properties of IrGa3: a promising thermoelectric material.

IrGa3 is an intermetallic compound which is expected to be a metal, but a study on the electronic properties of this material to confirm its metallic character is not available in the literature. In this work, we report for the first time a first-principles density functional theory and semiclassical Boltzmann theory study of the structural, electronic and transport properties of this material. The inclusion of the spin-orbit coupling term is crucial to calculate accurately the electronic properties of this compound. We have established that IrGa3 is an indirect semiconductor with a narrow gap of 0.07 eV. From semiclassical Boltzmann transport theory, it is inferred that this material, with the appropriate hole concentration, could have a thermoelectric figure of merit at room temperature comparable to other intermetallic compounds such as FeGa3, though the transport properties of IrGa3 are highly anisotropic.

Transfer parameters for ICRP's Reference Animals and Plants in a terrestrial Mediterranean ecosystem.

A system for the radiological protection of the environment (or wildlife) based on Reference Animals and Plants (RAPs) has been suggested by the International Commission on Radiological Protection (ICRP). To assess whole-body activity concentrations for RAPs and the resultant internal dose rates, transfer parameters are required. However, transfer values specifically for the taxonomic families defined for the RAPs are often sparse and furthermore can be extremely site dependent. There is also a considerable geographical bias within available transfer data, with few data for Mediterranean ecosystems. In the present work, stable element concentrations (I, Li, Be, B, Na, Mg, Al, P, S, K. Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Cs, Ba, Tl, Pb and U) in terrestrial RAPs, and the corresponding whole-body concentration ratios, CRwo, were determined in two different Mediterranean ecosystems: a Pinewood and a Dehesa (grassland with disperse tree cover). The RAPs considered in the Pinewood ecosystem were Pine Tree and Wild Grass; whereas in the Dehesa ecosystem those considered were Deer, Rat, Earthworm, Bee, Frog, Duck and Wild Grass. The CRwo values estimated from these data are compared to those reported in international compilations and databases.

Influence of architectural style on indoor radon concentration in a radon prone area: A case study.

Indoor radon is a major health concern as it is a known carcinogenic. Nowadays there is a trend towards a greater energy conservation in buildings, which is reflected in an increasing number of regulations. But, can this trend increase the indoor radon concentration? In this paper, we selected a radon prone area in Spain and focused on single-family dwellings constructed in a variety of architectural styles. These styles ranged from 1729 up to 2014, with varying construction techniques (from local resources to almost universally standard building materials) and regulations in force (from none to the Spanish regulation in force). The 226Ra concentrations in soil and surface radon exhalation rates were rather similar in this area, mean values ranging 70-126Bq/kg and 49-100mBq/m2·s, respectively. Indoor radon concentration was generally greater than the contribution from soil exhalation (surface exhalation rates), especially in New dwellings (1980-2014). Its concentration in dwellings built in the Traditional style (1729-1940) was significantly lower than in the new houses. This can be consequence of the air tightness of the dwellings as a consequence of the different regulations in force. In the period covered by the Traditional style, there was no regulation in force, and dwelling had loose air tight. Whereas in recent times, there are mandatory regulations assuring a better air tightness of the buildings. Refurbishment of Traditional dwellings also seems to increase the indoor radon concentration, as they must also comply with the regulations in force.

The electronic and optical properties of the sulvanite compounds: a many-body perturbation and time-dependent density functional theory study.

We have studied, by means of first-principles calculations, the electronic and optical properties of the sulvanite family: Cu3MX4 (M = V, Nb, Ta and X = S, Se), which, due to its broad range of gaps and chemical stability, have emerged as promising materials for technological applications such as photovoltaics and transparent conductivity. To address the reliability of those properties we have used semi-local and hybrid functionals (PBEsol, HSE06), many-body perturbation theory (G0W0 approximation and Bethe-Salpeter equation), and time-dependent density functional theory (revised bootstrap kernel) to calculate the quasi-particle dispersion relation, band gaps, the imaginary part of the macroscopic dielectric function and the absorption coefficient. The calculated valence band maximum and the conduction band minimum are located at the R and X-points, respectively. The calculated gaps using PBEsol are between 0.81 and 1.88 eV, with HSE06 into 1.73 and 2.94 eV, whereas the G0W0 values fall into the 1.91-3.19 eV range. The calculated dielectric functions and absorption coefficients show that all these compounds present continuous excitonic features when the Bethe-Salpeter equation is used. Contrarily, the revised bootstrap kernel is incapable of describing the excitonic spectra. The calculated optical spectra show that Cu3VS4 and Cu3MSe4 have good absorption in the visible, whereas Cu3NbS4 and Cu3TaS4 have it on the near ultraviolet.

Comparison of two methodologies used to estimate erosion rates in Mediterranean ecosystems: 137Cs and exposed tree roots.

The 137Cs deposited in soil and exposed tree roots have been widely applied to estimate medium-term soil erosion rates. However, comparative studies between these methods are scarce. For this purpose, three hillsides in two Mediterranean dehesas (rangeland with disperse tree cover) were selected. Regarding the 137Cs technique, a reference site close to the study areas and with similar altitude and rainfall was selected. In order to reduce uncertainties related to the use of point soil profiles, all those collected in an area were combined to form a representative composite profile. The total inventory was 2790±50Bq/m2, and the relaxation coefficient indicated it was an undisturbed soil. The radiocaesium inventory in the study areas was 14-23% lower than in the reference area. The erosion rates for 137Cs were in the range 20.9-38.1tha-1y-1. The exposed root technique was applied to holm oak trees (age about 90years), and the erosion rates were in the range 22-34tha-1y-1. The ratio between exposed root and 137Cs techniques was 1.02±0.11 (S.D.) within the range 0.89-1.2. Both methods produced very similar results equally with respect to the mean erosion rate as well as the relative difference between the hillslope sections, i.e. displaying the same spatial variation in the study areas. As the accounting time for these two techniques is different, 50 and 90y for 137Cs and exposed roots respectively, results suggest that no change in mid-term erosion rates was implied for these areas for almost a century. The use of 137Cs and exposed roots methodology for the determination of mean erosion rates can be reproduced in other ecosystems, but a careful selection of the reference site for 137Cs is essential.

Do fungi need to be included within environmental radiation protection assessment models?

Fungi are used as biomonitors of forest ecosystems, having comparatively high uptakes of anthropogenic and naturally occurring radionuclides. However, whilst they are known to accumulate radionuclides they are not typically considered in radiological assessment tools for environmental (non-human biota) assessment. In this paper the total dose rate to fungi is estimated using the ERICA Tool, assuming different fruiting body geometries, a single ellipsoid and more complex geometries considering the different components of the fruit body and their differing radionuclide contents based upon measurement data. Anthropogenic and naturally occurring radionuclide concentrations from the Mediterranean ecosystem (Spain) were used in this assessment. The total estimated weighted dose rate was in the range 0.31-3.4 µGy/h (5th-95th percentile), similar to natural exposure rates reported for other wild groups. The total estimated dose was dominated by internal exposure, especially from 226Ra and 210Po. Differences in dose rate between complex geometries and a simple ellipsoid model were negligible. Therefore, the simple ellipsoid model is recommended to assess dose rates to fungal fruiting bodies. Fungal mycelium was also modelled assuming a long filament. Using these geometries, assessments for fungal fruiting bodies and mycelium under different scenarios (post-accident, planned release and existing exposure) were conducted, each being based on available monitoring data. The estimated total dose rate in each case was below the ERICA screening benchmark dose, except for the example post-accident existing exposure scenario (the Chernobyl Exclusion Zone) for which a dose rate in excess of 35 µGy/h was estimated for the fruiting body. Estimated mycelium dose rate in this post-accident existing exposure scenario was close to the 400 µGy/h benchmark for plants, although fungi are generally considered to be less radiosensitive than plants. Further research on appropriate mycelium geometries and their radionuclide content is required. Based on the assessments presented in this paper, there is no need to recommend that fungi should be added to the existing assessment tools and frameworks; if required some tools allow a geometry representing fungi to be created and used within a dose assessment.

Cystic parathyroid adenoma: Primary hyperparathyroidism without 99mTc-MIBI uptake. / Adenoma quístico paratiroideo: hiperparatiroidismo primario sin captación de 99mTc-MIBI.

Cystic parathyroid adenoma is a rare disease (<0.01% of all cervical masses) that associates primary hyperparathyroidism in 9% of cases. Parathyroid scintigraphy is essential for its diagnosis with uncommon false negative results. Hybrid SPECT/CT equipments allow a more accurate diagnosis. Functional cystic parathyroid adenomas are surgically treated. A case of a 64-year-old woman with diagnoses of hyperparathyroidism and a cystic parathyroid adenoma without uptake in scintigraphy is described.