Mapping radon-prone areas using γ-radiation dose rate and geological information.

Identifying radon-prone areas is key to policies on the control of this environmental carcinogen. In the current paper, we present the methodology followed to delineate radon-prone areas in Spain. It combines information from indoor radon measurements with γ-radiation and geological maps. The advantage of the proposed approach is that it lessens the requirement for a high density of measurements by making use of commonly available information. It can be applied for an initial definition of radon-prone areas in countries committed to introducing a national radon policy or to improving existing radon maps in low population regions.

Setting radon-specific release criteria and demonstrating compliance for land affected by NORM.

Residues from industrial activities involving naturally occurring radioactive materials (NORMs) may cause radiation exposures to members of the public, particularly when NORM-affected land is brought into residential use. To provide an adequate protection against radiation in such situations, the following limiting criteria are currently required in Spain for releasing NORM-affected land: (i) no more than a 300 microSv yr(-1) increase (excluding radon doses) over the natural background; (ii) (222)Rn concentrations in hypothetical future dwellings lower than 200 Bq m(-3); and (iii) reduction of all radiation exposures to as low as reasonable achievable. This paper addresses some of the problems encountered in translating the (222)Rn criterion into site-specific release limits and in demonstrating compliance with them.

Natural ionizing radiation exposure of the Spanish population.

This study investigates the exposure of the Spanish population to natural radiation sources. The annual average effective dose is estimated to be 1.6 mSv, taking into account contributions from cosmic radiation (18%), terrestrial gamma radiation (30%), radon and thoron inhalation (34%) and ingestion (18%). Cosmic radiation doses were calculated from town altitude data. Terrestrial gamma ray exposure outdoors were derived from the MARNA (natural gamma radiation map of Spain); indoor exposure was obtained multiplying the corresponding outdoor value by an experimentally calculated conversion factor. Radon doses were estimated from national surveys carried out throughout the country. To assess doses by ingestion, data from a detailed study on consumption habits in Spain and average radioactivity values from UNSCEAR have been considered. The variability in the exposures among individuals in the population has been explicitly taken into account in the assessment.

Spanish experience on the design of radon surveys based on the use of geogenic information.

One of the requirements of the recently approved EU-BSS (European Basic Safety Standards Directive, EURATOM, 2013) is the design and implementation of national radon action plans in the member states (Annex XVIII). Such plans require radon surveys. The analysis of indoor radon data is supported by the existing knowledge about geogenic radiation. With this aim, we used the terrestrial gamma dose rate data from the MARNA project. In addition, we considered other criterion regarding the surface of Spain, population, permeability of rocks, uranium and radium contain in soils because currently no data are available related to soil radon gas concentration and permeability in Spain. Given that, a Spanish radon map was produced which will be part of the European Indoor Radon Map and a component of the European Atlas of Natural Radiation. The map indicates geographical areas with high probability of finding high indoor radon concentrations. This information will support legislation regarding prevention of radon entry both in dwellings and workplaces. In addition, the map will serve as a tool for the development of strategies at all levels: individual dwellings, local, regional and national administration.

Radon measurements with a PIN photodiode.

Silicon photodiodes are well suited to detect alphas coming from different sources as neutron reactions or radon daughters. In this work a radon in air detecting device, using an 18x18 mm silicon PIN photodiode is studied. The ionized airborne decay products formed during radon diffusion were focused by an accelerating high voltage to the PIN surface. Several conducting rings were disposed inside a cylindrical PVC vessel in such a way that they reproduced the electric field created by a punctual charge located behind PIN position. Alpha spectra coming from the neutral and ionized species deposited on the PIN surface, dominated by 218Po and 214Po progeny peaks, were recorded for varying conditions. Those include radon concentration from a Pylon source, high voltage (thousands of volts) and PIN inverse bias voltage. Different parameters such as temperature and humidity were also registered during data acquisition. The increase in the particle collection efficiency with respect to zero electric field was compared with the corresponding to a parallel plates configuration. A discussion is made in terms of the most appropriate voltages for different radon concentrations.

Evaluation of the suitability of various gamma lines for the gamma spectrometric determination of 238U in environmental samples.

Gamma-ray spectrometry is extensively used for 238U determination because of its simplicity in terms of sample preparation. Nevertheless, processing of measurement data presents several challenges, such as evaluation of overlapping photopeaks and calibration of detector efficiencies for different matrices and photon emissions. Besides, the emission probability data for 238U and its daughters show significant discrepancies among different studies. In this study, we assess the suitability of four methods, using the photopeaks at 63.3, 92.6, 766.4 and 1001.0 keV, respectively, to determine 238U in environmental samples. With that aim we analyse several reference and environmental samples, detailing the entire procedure involved in the calculation of the 238U activities and highlighting possible error sources. Based on the results obtained, we propose new yields for the 234Th photons and compare these to corresponding values from the literature.

A hybrid method to compute accurate efficiencies for volume samples in gamma-ray spectrometry.

In recent years, Monte Carlo (MC) methods have been increasingly applied to cope with variability in photopeak efficiencies due to matrix effects. But to obtain proper results only by numerical simulation, especially at low energies, sample bulk density and chemical composition must be well characterized. In this paper, we propose a method that combines both experimental measurements and MC simulations, being applicable to matrices of unknown composition. A transmission measurement of a 210Pb point source through the sample allows one to compute accurately its photopeak efficiencies at energies above 46.5 keV. The method is validated for several inorganic and organic matrices measured in Petri dishes geometry.

Radon emanation measurements using silicon photodiode detectors.

Driven by the global concern about radon hazards, a wide variety of methods to measure radon and its decay products have been developed. Pin silicon photodiodes are increasingly applied in this field, their main advantages being high detection efficiency for alpha particles and low cost. In this paper, we present a system to determine the emanation factor for 222Rn from porous material based on a pin photodiode. This equipment is valid both for field and laboratory measurements, allowing to monitor the external emanation conditions by means of temperature, humidity and pressure sensors. To illustrate the capabilities of the system, we present two case studies of samples with high and low 226Ra content. The activity of this radionuclide in the samples had been previously determined by gamma-ray spectrometry.

Natural radiation doses to the population in a granitic region in Spain.

The global average effective dose from natural radiation sources is estimated to be 2.4 mSv y(-1). Nevertheless, local variations in the radiation exposure may differ by orders of magnitude. In this paper, we study a rural area in western Salamanca (Spain) where doses are potentially well above the stated average value. Its geology consists mostly of granite and schist, presenting various uranium mineralisations, some of which were exploited in former years. Water samples, both surface and groundwater, were collected in selected villages and measured by liquid-scintillation spectrometry. 222Rn in dwellings was determined in dwellings by means of short-term measurements, using Picorad vials and long-term measurements with CR-39 detectors. The committed effective doses to the inhabitants due to indoor 222Rn and 222Rn and 226Ra in drinking water were assessed using the dose conversion factors proposed in the UNSCEAR 2000 report.

The Spanish indoor radon mapping strategy.

Indoor radon mapping still represents a valuable tool for drawing the picture of the exposure of general public due to radon and radon progeny inhalation in a residential context. The information provided by means of a map is useful not only as awareness and strategic element for authorities and policy-makers, but also as a scientific start-up point in the design of epidemiological and other specific studies on exposure to natural radiation. The requirements for a good mapping are related to harmonisation criteria coming from European recommendations, as well as to national/local characteristics and necessities. Around 12,000 indoor radon measurements have been made since the Spanish national radon programme began at the end of the 1980s. A significant proportion of them resulted from the last campaign performed from 2009 to 12. This campaign completed the first version of a map based on a grid 10 × 10 km(2). In this paper, the authors present the main results of a new map together with the criteria adopted to improve the number of measurements and the statistical significance of them.

A regulatory perspective on the radiological impact of NORM industries: the case of the Spanish phosphate industry.

Radioactive and chemical risks coexist in NORM industries although they are usually addressed separately by regulations. The European Union (EU) has developed extensive legislation concerning both matters, which has been diversely reflected in national policies. We consider the case of the Spanish phosphate industry and analyse to which extent regulatory mandates have reduced the historical and ongoing radiological impact on the environment of phosphate facilities. Although no specific radiological constraints on effluent monitoring and release or on waste disposal have yet been imposed on NORM industries in Spain, other environmental regulations have achieved a substantial reduction on the phosphate industry impact. Nevertheless, a more efficient control could be established by eliminating the current conceptual and practical separation of chemical and radioactive risks in NORM industries. We highlight research needs to accomplish so and propose shorter-term measures that require active cooperation among the regulatory bodies involved.

Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities.

In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5×10(-5)mSv/y, in contrast to 1.6mSv/y from natural radiation or 1.3mSv/y from medical exposures.

Dermatomicosis por Candida krusei simulando herpes cutáneo / Candida krusei dermatomycoses simulating cutaneous herpes

Las infecciones fúngicas de la piel suelen producirse por hongos dermatofíticoszoofílicos o antropofílicos con capacidad para colonizar tejidos queratinizados (piel, pelo o uñas).Se denominan genéricamente tiñas y se clasifican de forma topográfica según zona afectada empleando el modo genitivo latino (corporis, capitis, unguis, manus, pedis). La tiña faciei es una variedad de la tiña corporis que interesa exclusivamente a la cara. El género Candida no pertenece a los dermatofitos; se trata de una levadura saprofita de piel y mucosas que, en determinadas condiciones que disminuyen la resistencia del hospedador, se hace prevalente sobre el resto de flora cutánea comensal, produciendo daño más por una disminución de las resistencias del individuo que por su capacidad patogénica per se. La especie habitualmente aislada suele ser C. albicans, pero en algunas situaciones las lesiones cutáneas están producidas por otras especies (denominadas globalmente no-albicans), que suelen ser responsables de cuadros sistémicos. Cuando afectan a piel, las manifestaciones clínicas son más inespecíficas y su diagnóstico puede diferirse; además presentan implicaciones terapéuticas particulares por la pobre respuesta a otros productos que sí son efectivos para C. albicans, de ahí la importancia de un detenido examen físico ante las dermatomicosis (AU)

Fungal skin infections are usually caused by zoofilic or antropophilic dermatophytes with ability for colonizing keratinized tissues (skin, hair, nails).They are generally called tinea and are classified topographically using the Latin genitive mode (corporis, capitis, unguis, manus, pedis). Tinea faciei is a variety of the corporis type where only face is affected. The genus Candida does not belong to dermatophytes, it is a saprohytic yeast of skin and mucous membranes that under certain conditions that decrease host resistance become prevalent over other skin commensal flora and causes damage due to a drop in immunologic individual status more than its pathogenic capacity per se. The commonly isolated species usually is C. albicans, but in some situations the skin lesions are produced by other species (called globalynon-albicans) that usually cause systemic diseases. Clinical manifestations, when skin is affected, are nonspecific and diagnosis can be delayed. Also they have special therapeutic implications due to poor response to other drugs with effectiveness in C. albicans. Hence, a thorough physical examination is of the most importance for dermatomycoses (AU)

Reestenosis hipertófica de píloro tras piloromiotomía, ¿recurrencia verdadera o complicación posquirúrgica? / Recurrent Infantile hypertrophic pyloric stenosis after pyloromyotomy: progression of original disease or delayed surgical complication?

La recurrencia de estenosis hipertrófica de píloro es una entidad rara. Debe sospecharse ante la aparición de vómitos proyectivos tras un periodo postoperatorio sin incidencias por piloromiotomía previa. Suele obedecer a cirugía anterior insuficiente o a lesión duodenal intraoperatoria y habitualmente precisa nueva cirugía reparadora. Se presentan dos casos de reestenosis hipertrófica de píloro, y se discute la naturaleza de esta estidad (AU)

Recurrent Infantile hypertrophic pyloric stenosis is a rare condition. It must be suspected if new projectile vomiting reoccurs after an uneventful postoperative period. It is usually caused by incomplete previous surgery or accidental duodenal injury during Ramstedt’s procedure. In general a new pyloromyotomy is required. Two cases of hypertrophic pyloric restenosis are presented, and the nature of this condition is discussed (AU)

Towards a proper modeling of detector and source characteristics in Monte Carlo simulations

We performed a systematic study on the influence of different source configurations on the reliability of Monte Carlo calculations for the response of Ge detectors. Calculated full-energy peak efficiencies are compared to experimental values in the energy range 46-1800 keV. Setups with different characteristics are considered, from point-like to volume sources. Among the latter there are filters and aqueous matrices and sediments in Petri boxes or Marinelli beakers. The analysis of the deviations between experimental and calculated results for the different configurations enables us to detect inaccuracies in the description of detector and source characteristics and to improve them. By means of this procedure satisfactory results of the efficiencies were obtained in the whole energy range. For all setups, the deviations average 1.5%, except for the sediment sources where they are up to 3.3%.

Morganella morganii: bacteria inusual en líquido articular / Morganella morganii: An unusual bacterium in joint effusions

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Rotavirus: vieja enfermedad, nuevas vacunas / No disponible

El rotavirus es la causa más importante de diarrea en la infancia. En países en vías de desarrollo presenta una gran morbimortalidad, siendo responsable de casi 500.000 muertes en niños menores de 5 años cada año. Por otro lado, en Europa y Norteamérica cerca de la tercera parte de todos los ingresos hospitalarios por gastroenteritis se deben a este microorganismo. La infección por rotavirus afecta prácticamente a la totalidad de los niños hasta los 5 años de edad, aunque las formas graves de la enfermedad ocurren sobre todo entre los 3 meses y los 3 años. El virus aparece en altas concentraciones en las heces de los niños enfermos y tiene una gran capacidad de transmisión entre individuos. La carga de la enfermedad y el costo social y económico son muy elevados, alcanzando los 1.600 euros por cada ingreso. En 2006 se han comercializado en nuestro país dos nuevas vacunas orales. Ambas demuestran un muy buen perfil de seguridad y una elevada eficacia en la prevención de enfermedad grave, deshidratación y hospitalizaciones por gastroenteritis en población infantil

Rotavirus is a major cause of diarrhoea in childhood. It shows an enormous morbidity and mortality in developing countries, being responsible for approximately half a million deaths per year among children aged less than five years. In the other hand in Europe and United States of America nearly one third of admissions by gastroenteritis are due to this microorganism. Rotavirus infects almost all infants by the age of five years, although severe disease appears almost always in children of three to thirty-six months. Rotavirus appears in high concentrations in the stools of infected children having an increasing capacity of transmission person to person. Burden of the disease and its social and economic cost are extremely high reaching one thousand and six hundred euros by each hospitalization. Two new oral vaccines have been commercialized in our country last year. Both of them report an excellent profile of security and a high efficacy in the prevention of severe disease, dehydration and admissions to hospital because of gastroenteritis in the childhood population (AU)

Tumor estromal gástrico de estirpe neural: ¿neoplasia aislada o primera manifestación del complejo de Carney? / Gastrointestinal autonomic nerve tumor: isolated neoplasm or first manifestation of Carney’s complex?

Los tumores gastrointestinales de naturaleza estromal son especialmente infrecuentes en niños. Presentan de forma genérica 2 vías de diferenciación: hacia la estirpe muscular (variante mioide) o como célula neural. Carney publicó en 1978 el primer caso de un tumor de este tipo asociado a neoplasia pulmonar (condroma) y neural (paraganglioma extradrenal). Los 3 tumores presentan un origen ectodérmico común, lo que daría origen a la aparición sinérgica o secuencial de éstos a lo largo de la vida del individuo, y obligaría a realizar un estudio completo ante la aparición de cualquiera de ellos. Comunicamos el caso de una niña de 11 años que presentó un tumor estromal gástrico, cuya única manifestación clínica fue una anemia sintomática

Gastrointestinal stromal tumors (GIST) are highly uncommon in childhood. There are two specific differentiation patterns: toward a smooth muscle cell lineage (myoid variant) or toward a neural lineage (gastrointestinal autonomic nerve tumors [GANT]). In 1978, Carney reported the first case of this type of tumor associated with two other neoplasms, pulmonary chondroma and extraadrenal paraganglioma. All three tumors seem to have a common ectodermal origin, and their synergic or sequential presentation throughout the individual’s life may be observed. Thus, the detection of any of these three tumors should lead to a complete study of the patient. We report the case of an eleven-year-old girl with a GIST in whom the only clinical sign at presentation was symptomatic anemia