63 research outputs found
Radiological evaluation associated to the mining and concentration of monazite in Central Spain
Trabajo presentado a la 4th International Conference on Environmental Radioactivity: Radionuclides as Tracers of Environmental Processes, celebrada en Vilnius (Lithuania) del 29 de mayo al 2 de junio de 2017.A detailed radiological evaluation (occupational, public and environmental) has been performed associated with the mining and physical concentration of monazite, enriched in different rare earths, in a zone to be exploited commercially which is located 200 km at the south of Madrid (Spain). This evaluation is performed because the rare earth extraction mining and concentration steps are activities recognized in the positive list of NORM activities to be analysed for possible adoption of radiological controls.Peer reviewe
Natural radionuclides (NORM) in a Moroccan river affected by former conventional metal mining activities
The main aim of this work was to determine the levels of multiple natural radionuclides in an aquatic system (Moulouya river, Morocco) impacted by multiple abandoned Zinc and Lead mines. 238U, 234U, 232Th, 230Th and 210Po were determined by alpha-particlespectrometry in water and sediment samples collected along the river and in samples from three pit lakes of abandoned mines, located in the Upper Moulouya catchment area. The results enabled the analysis of the different levels of impact of former mining activities, depending on the natural radionuclides. While the activity concentrationof U-isotopes in Moulouya river water was slightly elevated in the vicinity of abandoned mine wastes, other natural radionuclides (Th-isotopes and 210Po) levels were typical of a natural environment. This fact is clearly reflected in the magnitude and range observed in the distribution coefficients for the different radionuclides analyzed.Spanish Agency of International Cooperation and Development (AECID) of the Government of Spai
Adelante / Endavant
Séptimo desafío por la erradicación de la violencia contra las mujeres del Institut Universitari d’Estudis Feministes i de Gènere "Purificación Escribano" de la Universitat Jaume
El Polonio en la cadena alimenticia: Implicaciones dosimétricas
Esta memoria se puede considerar dividida en dos grandes bloques: -Una primera parte metodológica donde se ha realizado a) una descripción de las técnicas radiométricas experimentales utilizadas para la determinación fundamentalmente de 210Po en matrices ambientales, así como una exposición de los trabajos realizados para sus calibraciones y puestas a punto, y b) una descripción de los procedimientos físico-químicos y radioquímicos utilizados como etapa esencial previa para la medida radiométrica de los radionucleidos de interés, poniendo especial énfasis en detallar las labores de optimización llevadas a cabo por nosotros en los mencionados procedimientos.
-Una segunda parte, fundamentalmente de aplicación donde: a) se han determinado las concentraciones de actividad de 210Po y otros radionucleidos naturales de la serie del uranio en un conjunto amplio de muestras de aguas minerales y distintos tipos de alimentos, como base para la determinación de las dosis por ingestión y b) se han determinado las concentraciones de actividad de 210Po en muestras de orina y pelos, con el fin de iniciar la creación de una base de datos fundamental para la realización de estudios dosimétricos y con el fin de correlacionar la ingesta con la eliminación de 210Po.Peer Reviewe
El 210 Po en la cadena alimenticia humana
Revista de la Sociedad Española de Protección Radiológica (SEPR): Monográfico radiactividad ambiental.[ES]: El 210Po es un radionucleido natural perteneciente a la serie radiactiva del Uranio, presente de forma ubicua en cantidades traza en los diversos compartimentos de la naturaleza (aguas, suelos, biota) y que a tráves de su ruta de la cadena trófica puede ser incorporado al cuerpo humano mediante ingestión de aguas y alimentos. Este radioisótopo se caracteriza por su alta radiotoxicidad, siendo uno de los principales contribuyentes a la dosis comprometida por ingestión recibida por la población. La contribución de este radionucleido a las dosis recibidas por el consumo de aguas embotelladas y por la ingestión de dietas representativas del hábito alimenticio de la población sevillana es evaluada en este trabajo, y comparada con las contribuciones debidas a otros radionucleiods naturales y artificiales.[EN]: 210Po ia a natural occurring radionuclide, belonging to the Uranium series, which is present in minute amounts in the different environmental compartments (water, soil, biota) and that through its route along the trophic chain can finish incorporated in the human body via ingestion of waters and/or food. This radionuclide is highly radiotoxic, being one of the main contributors to the committed effective dose via ingestion received by the population of seville via consumption of bottled waters and via ingestion of typical diets is evaluated. The mentioned contribution is also compared with the contributions of other natural and artificial radionuclides.Peer reviewe
Activity levels of 210Po in marine organism consumed in south of Spain
Trabajo presentado a la II International Conference on Radioecological Concentration Processes (50 years later), celebrada en Sevilla (España) del 6 al 9 de noviembre de 2016.The distribution and behaviour of Polonium (210Po) in marine organisms has been and is now a subject of great interest because of their relatively high concentrations in comparison with those in terrestrial organisms and its relatively high weight in the doses received by humans via ingestion. However, depending of the specimen analysed and its relative position along the marine food chain, the 210Po activity levels can be quite different, even in several orders of magnitude. 210Po is primarily absorbed from water and concentrated by phyto- and microzooplankton, and then is transferred to the next trophic level along the marine food chains. In this work, the contribution of 210Po to the committed effective dose via ingestion received by the Spanish population have been evaluated, by determining the 210Po activity concentrations in an ample set of samples which can be considered representatives of the different marine organisms consumed in Spain. The obtained results show a quite high variability, preventing the possibility to fix a representative value for the 210Po contribution to the ingestion doses received by the Spanish population, but in general these values, due exclusively to 210Po, are higher than the average value assigned by UNSCEAR to the annual committed effective dose received by the worldwide population due to the ingestion of natural and anthropogenic
radionuclides.Peer reviewe
210Po en organismos marinos consumidos por la población sevillana
Trabajo presentado al 2º congreso conjunto de las Sociedades Españolas de Física Médica y de Protección Radiológica (XVIII Congreso Nacional SEFM/XIII Congreso Nacional de SEPR) celebrado en Sevilla del 10 al 13 de Mayo de 2011.[ES]: El 210Po es un radionucleido de la serie natural del uranio presente en los distintos compartimentos naturales y que se caracteriza por presentar una alta radiotóxicidad y tener un comportamiento bioacumulativo en determinados tejidos en seres vivos. Por lo tanto, contribuiye a la dosis recibida en organismos del medio marino y, consecuentemente tras su ingesta, a las dosis por ingestión en la población que los consuma. Este trabajo muestra la dosis asociada a dicho consumo sobre un amplio espectro de especies marinas frecuentemente consumidas en Sevilla. Las muestras fueron cocinadas en la forma habitual de consumo y tras este proceso, se ha llevado a cabo un proceso de digestión mediante microondas con una posterior medida del 210Po por espectrometría alfa. Los valores de 210Po encontrados varían hasta en tres órdenes de magnitud (desde 0,09±0,01 Bq/kg peso húmedo en sepia preparada a la plancha hasta 140±4 Bqkg-1 en boquerones en vinagre) generando estos últimos una dosis de 340 Sv/año estimada sobre la base de un consumo típico de esta especie. Los resultados obtenidos ponen de manifiesto las altas concentraciones de 210Po en algunas especies marinas consumidas con asiduidad por la población sevillana que son, por otra parte, en la mayoría de los casos uno o varios órdenes de magnitud superiores a las determinadas para otros radionucleidos pertenecientes a su misma serie radiactiva natural como los isótopos de Uranio (234U y 238U). Ello, unido a su alta radiotoxicidad, convierte al 210Po en el radionucleido natural que contribuye en mayor proporción a la dosis por ingestión recibida por la población sevillana debida al consumo de estos productos.[EN]: 210Po is a natural radionuclide belonging to the uranium series that can be found in different conpartments in the environment. It is characterized for presenting a high radiotoxicity and a bioaccumulative behavior in some biological tissues. This is why it contributes strongly to the dose received by marine organisms, and consequently after consumption, to the ingestion dose in the population that consume them. This work shows the doses ssociated with this consumption on a wide range of marine species frequently consumed in Seville. The samples were cooked in the usual way they are ingested. After this process, a microwave digestion was carried out followed by a final measurement of 210Po via alpha spectrometry. The values found for 210Po range up to three orders of magnitude (from 0.09 ± 0.01 Bqkg-1 wet weight in prepared grilled cuttlefish to 140 ± 4 Bqkg-1 in anchovies in vinegar) generating the last one a dose of 340 Sv/year, estimated on the basis of a typical consumption of this species. With these results, it is proved the high concentrations of 210Po in marine species regularly consumed by the population of Seville. Compared to other radionuclides belonging to the same natural radioactive series, uranium isotopes (234U and 238U) has, in most cases, one or several orders of magnitude lower concentrations than polonium isotopes. This fact together with the high radiotoxicity of polonium, makes the 210Po as the natural radionuclide that contributes the most to the ingestion dose received by the population of Seville due to consumption of these products.Peer reviewe
Natural levels of 210Po in human urine
Resumen del póster presentado a la "3rd International Conference on Radioecology and Environmental Radioactivity" celebrada en Barcelona (España) del 7 al 12 de septiembre de 2014.Since the secret agent Alexander Litvinenko was murdered in 2006 by a 210Po lethal dose, presumably ingested, there is renovated interest on the toxicity of this radionuclide in humans. 210Po is a radioactive isotope naturally found in nature, mainly incorporated by humans via food and water ingestion, as well as inhaled through its progenitor, the 222Rn. The total amount of natural 210Po in the human body can vary from person to person depending on their lifestyle: dietary habits, drinking water source, place of residence (associated with exposure to 222Rn), etc- and therefore in the concentrations of this element to be found in urine. To analyze the influence of dietary habits on the amount of 210Po excreted in urine, two volunteers in Seville had a well-defined and time-varying diet for a month, following a daily collection of their urine and determination of the concentrations therein of this radionuclide. The results obtained and the conclusions derived from them form the core of this communication. 210Po determinations were performed daily in 200 ml aliquots of urine using the technique of high resolution alpha spectrometry. This has involved the application of a single radiochemical method for the concentration and isolation 210Po, followed by its auto-deposition on copper planchets for proper measure. Daily 210Po activity concentrations in voluntary urine analyzed during the month of study show high variability with a difference of up to an order of magnitude between maximum and minimum values obtained, and a clear dependence on the diet type followed in the various stages of the experiment. The lowest concentrations obtained are associated with a diet rich in carbohydrates and proteins 'terrestrial' (pork, beef,...), while the highest concentrations were obtained in the final phase of the experiment when the diet was enriched with presence of marine products in fair correspondence with the highest 210Po content in recent products. The use of urine to monitor a population critical group after a hypothetical terrorist act that involving possible 210Po making inadvertent ingestion or inhalation requires in practice the choice of a reference threshold that allows discrimination between the existing natural 210Po in urine under study and the possible contribution of 210Po anthropogenic. The high variability observed by us naturally 210Po concentrations in urine makes it not far from trivial to set that threshold value, being moreover obvious that its value should not be set based on the choice made in other countries because their dietary habits and lifestyle can be very different. We consider it essential to create a database nationwide 210Po activity concentration in urine associated information in each case on donor diets and lifestyle. This database must contain a statistically representative number of data enough to get them the information necessary for an appropriate choice of the threshold mentioned regional or national scale in possible emergency cases.Peer reviewe
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