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This study was conducted at the Institute of Arid Regions of Gabes in Tunisia. Three plots were left as controls and received no input, three plots were amended with cattle manure with a dose equivalent to 37.5 t/ha, and nine plots were amended with phosphogypsum in three doses (12.5 t/ha, 25 t/ha, and 50 t/ha), with three repetitions for each dose. A pot test to determine the germination index and radioactivity analysis was carried out in the laboratory. The results showed that organic manure amendments and phosphogypsum improved the germination rate of the different crops (jute mallow, turnip, and oat) compared with the control. At the same time, the 50 t/ha dose had the highest germination rate. An increase in yield of all crops during the whole duration of the experiment was observed for the soil amended by phosphogypsum. The best yield was recorded when the highest dose of phosphogypsum was applied. The cadmium level in plants of the two applied amendments was variable but still below the toxicity threshold (7 ppm). The values recorded following the analysis of the phosphogypsum radioactivity showed that the mean value of Ra-226 equals 214.45 Bq/kg, which is below the limit announced by the EPA (Environmental Protection Agency). The radioactivity results from the control soil samples showed the presence of natural radioactivity. Samples of phosphogypsum-amended soil and plants grown in these soils have radioactivity values that are still lower than those announced by the EPA. The novelty aspect of this study is the application of phosphogypsum in different crops during two consecutive years in degraded-soil areas of Tunisia, in addition to the study of different aspects of phosphogypsum reuse in agriculture as a promising strategy for a sustainable environment.

In the salth-marshes of the Tinto River (Huelva estuary, SW Spain), are stored in stacks around 100 Mt of PG, covering a surface of 1000 ha without any type of isolation, which produce an important impact in the surrounding environment. On the other hand, this ecosystem it is affected by acid mine drainage (AMD) from sulphide mines located upstream the Tinto River. The aim of this study is to evaluate the deep pollution of the underlain salt-marsh sediments due to leachates from the PG stacks. For that purpose, 7 cores were collected from zones 2 and 3 of the stacks, and PG and salt-marsh sediments samples from different depths were analyzed. The physicochemical parameters, mineralogy, granulometry and the concentration of the main elements of interest were determined in the samples. Most analysed salt-marsh sediments are not affected by PG stacks pollution, because sediments act as a “barrier” for the leachates from the PG, concentrating the contaminants in the first decimetres (0.5 m) under PG-sediments contact, and the deep infiltration is very limited. The obtained results suggest that the perimeter channel which is projected to build in the restauration project, should has a depth of 1 m below the level of the PG stacks for assuring the complete collection of leachates from the stacks, and avoid their liberation into the Tinto River estuary.

The mining activities performed in the Iberian Pyrite Belt (south of Spain) have generated since long-time acid mining drainage (AMD) inputs to the Odiel River and its tributaries. These inputs are continuing nowadays, with origin mostly in the abandoned mines that cover the area, provoking a steady-state situation where the river waters present very low pH and very high concentrations of different heavy metals. In this work, the behavior of several natural radionuclides (210Po, Th- and U-isotopes) in water and sediment samples collected in the Odiel River and its tributaries have been analyzed and their levels determined looking for assessing the radiological environmental impact of the AMD.

The activity concentration of polonium-210 in the soft tissue of several species of mollusks of coastal areas from Tabasco, Mexico, has been determined. Polonium-210 is a natural radionuclide that may be bioaccumulated by flora and fauna, particularly by mollusks. Radioecological evaluation of polonium-210 in mollusks is of particular interest for environmental radioactivity surveillance and to understand the mechanisms of migration of this radionuclide from the environment to humans. In this work, an analysis of the levels of polonium-210 in mollusks from Mexico is presented. Methods include the use of alpha-particle spectrometry to measure polonium-210 in the soft tissue of the studied mollusks. Results show an average value of 158 Bq/kg in mollusks from Tabasco, Mexico. Mollusks from the taxonomic class Bivalvia bioaccumulate more polonium-210 than Gastropods. The activity concentration values of polonium-210 in mollusks from Mexico are of the same order as those reported internationally. A further work on the mechanisms of migration and bioaccumulation of polonium in these organisms is necessary. Consejo Nacional de Ciencia y Tecnología (Scholarship: 454803; CVU: 269695)

Part of a collection: Focus Point on Small and Medium and Particle Accelerator Facilities in Europe, The Centro Nacional de Aceleradores is a user-oriented accelerator facility in Seville, Spain. Its main facilities are a 3 MV tandem accelerator, an 18 MeV proton Cyclotron, a tandetron used for AMS, a compact accelerator used for radiocarbon measurements, a Co irradiator and a PET/CT scanner. The technical specifications and research applications of these facilities are described. A neutron beam line associated to a charged pulsed beam in the tandem allows for time of flight measurements which determine the neutron energy. The use of an adequate stripper gas in the AMS tandetron permits to measure heavy radionuclides with very low detection levels, allowing to perform environmental studies using these radionuclides as tracers. The use of the microbeam in the tandem accelerator allows to apply the ion beam-induced current technique to investigate the spectroscopic properties and radiation hardness of different semiconductor detectors., Also the funding made available for infrastructures through the ICTS program of the Spanish ministry of science, making use of FEDER funds from the European Union. The continuous support of CNA patrons, the University of Seville, the Junta de Andalucía and CSIC is acknowledged. Private funds, through contracts with companies and institutions, such as Curium, Alter technologies, and the andalusian health service (SAS), made possible to maintain contracts of key personnel. We acknowledge the funding of projects by the European Union, H2020-847594, H2020-654002, H2020-847552, H2020-847594 , by the Spanish ministry of science RTI2018-098117-B-C21, RTC-2017-6369-3, EQC2018-004193-P, EQC2018-004095-P, EQC2018-004166-P, PGC2018-094546-B-I00, and by the Junta de Andalucía FEDER progrem US-1261006, US-1263369, P18-RT-1900.

Along the industrial process devoted to the production of titanium dioxide pigments by using ilmenite as main raw material, small residues amounts are generated, remaining clearly enriched in natural radionuclides and chemical pollutants. Between them, we can remark the scales enriched in both radium isotopes and lead, which are formed in the internal walls of pipes and some equipment. These scales are radiological anomalies that demand its mineralogical, elemental and radiometric characterization as a basis for a detailed radiological and toxicological assessment from the occupational and public point of view. In this work, several scales collected in a TiO2 pigment production plant in South of Spain have been mineralogically characterized by XRD, while information about their elemental composition and morphology have been obtained by applying the XRF and SEM techniques. In addition, radiometric determinations have been performed by gamma-ray and alpha-particle spectrometry. The performed study indicates that the radiological doses received due to the scales by the workers performing its conventional activities are clearly lower than 1 mSv/y. Special dosimetric and chemical controls could be needed for the workers in charge of the maintenance labours (which include the removal of the scales) if these workers belong to an external company devoted to perform maintenance operations in several NORM industries., This research was partially supported by the Spanish Government Department of Science and Technology (MINECO) through the project "Fluxes of Radionuclides Emitted by the Phosphogypsum Piles Located at Huelva; Assessment of the Dispersion, Radiological Risks and Remediation Proposals" (Ref. CTM 2015-68628- R), ), and the project of the Regional Government of Andalusia called “Basic processes regulating the fractionations and enrichments of natural radionuclides under acid mine drainage conditions” (Ref.: UHU-1255876) and the project of the University of Cadiz called "New methodogy of radioisotope isolation with environmental interest for its measurement by alpha spectrometry" (Ref: PR2019-024). The authors acknowledges to the staff of CITIUS at the University of Seville their help in the application of the X-ray techniques.

Natural radioactivity in the environment is a field gaining more attention in last decades. This work is focused on the study of natural radioactivity complemented with elementary characterization at former non-uraniferous mining areas in Sweden. This aim is addressed through the study of mining lakes, called pit lakes, which are water bodies generated after opencast mining. Environmental matrices (water, sediments and rocks) from 32 Swedish pit lakes, commonly used for recreational purposes were radiometrically characterized via alpha (238U, 234U, 232Th, 230Th, 210Po isotopes) and gamma spectrometry (238U and 232Th series radionuclides). Additionally, ambient dose rate equivalent in the immediate surrounding of each pit lake was quantified. Physico-chemical parameters (pH, specific conductivity, dissolved oxygen, oxidation–reduction potential) and elemental composition (major and trace elements by ICP-MS) were analysed in water samples and elementary composition of sediments/rocks was measured by XRF and SEM–EDX in some specific cases. A non-negligible number of pit lakes (26%) with enhanced U levels in water was found. At some sites, rocks contained up to 4% of U in areas with high degree of interaction with local population. Concerning the elementary perspective, another popular site (due to its turquoise water) was found to have elevated dissolved heavy metal levels. Results obtained in this work prove that measurement of natural radioactivity is another component that should be included in routine analysis of characterization in mining areas, especially if restauration of post-mining sites is intended for human recreational., Work supported by the Swedish Radiation Safety Authority (SSM2014-3485). The authors thank Dr. Ana Calleja at Radioisotopes Laboratory (ICP-MS measurements) and the X-Ray Laboratory staff (XRF measurements), both from CITIUS facilities at the University of Seville. Furthermore, the Applied Nuclear Physics Group at the University of Seville, is also acknowledged for its continuous technical support during the different stages of this project. Open access funding provided by University of Gothenburg.

A series of different nuclear sources associated with the nuclear weapon and fuel cycles have contributed to the release of radioactive particles to the environment. Following nuclear weapon tests, safety tests, conventional destruction of weapons, reactor explosions and fires, a major fraction of released refractory radionuclides such as uranium (U) and plutonium (Pu) were present as entities ranging from sub microns to fragments. Furthermore, radioactive particles and colloids have been released from reprocessing facilities and civil reactors, from radioactive waste dumped at sea, and from NORM sites. Thus, whenever refractory radionuclides are released to the environment following nuclear events, radioactive particles should be expected. Results from many years of research have shown that particle characteristics such as elemental composition depend on the source, while characteristics such as particle size distribution, structure, and oxidation state influencing ecosystem transfer depend also on the release scenarios. When radioactive particles are deposited in the environment, weathering processes occur and associated radionuclides are subsequently mobilized, changing the apparent K d . Thus, particles retained in soils or sediments are unevenly distributed, and dissolution of radionuclides from particles may be partial. For areas affected by particle contamination, the inventories can therefore be underestimated, and impact and risk assessments may suffer from unacceptable large uncertainties if radioactive particles are ignored. To integrate radioactive particles into environmental impact assessments, key challenges include the linking of particle characteristics to specific sources, to ecosystem transfer, and to uptake and retention in biological systems. To elucidate these issues, the EC-funded COMET and RATE projects and the IAEA Coordinated Research Program on particles have revisited selected contaminated sites and archive samples. This COMET position paper summarizes new knowledge on key sources that have contributed to particle releases, including particle characteristics based on advanced techniques, with emphasis on particle weathering processes as well as on heterogeneities in biological samples to evaluate potential uptake and retention of radioactive particles.

Phosphogypsum (PG) is a type of synthetic gypsum generated during the production of phosphoric acid . Each ton of phosphoric acid generates 5 tons of phosphogypsum. This industrial process has caused significant environmental problems worldwide. After an extensive literature review, it has been possible to verify that both sedimentary and igneous PG can be used as materials building components. The use of PG up to 50% meets the limits required for index I, with a radioactivity equivalent to radio-226 and a concentration of radon-222. The data found on bricks (0,11-0,41 Bq m -2 h-1) and plate (0,16-0,41 Bq m-2 h-1 ) show a lower exhalation rate. It is also found that calcination contributes to the reduction of PG impurities, and the mechanical strength increase. Mortars and concretes produced with PG-based cementitious systems achieve high compressive strength levels (60 MPa, 70 MPa, 80 MPa) and accomplish the requirements of the European standards EN 998-1, EN 998-2, EN 13813, Eurocode 1992 and the American standard ASTM C270 . The mineral phase of PG influences the setting time. It is concluded that cementitious materials produced from phosphogypsum are technically viable and achieve satisfactory performance in some building areas. The following open research lines have been detected: PG-based concrete with high performance, PG-based hydration cement, stabilized mortar, PG-based concrete with high workability, and studies on durability (e.g. chloride ingress, carbonation , sulphate attack and acid attack in PG-based concrete).

Leached fractions of U and Th from different environmental solid matrices were evaluated by an automatic system enabling the on-line lixiviation and extraction/pre-concentration of these two elements previous ICP-MS detection. UTEVA resin was used as selective extraction material. Ten leached fraction, using artificial rainwater (pH 5.4) as leaching agent, and a residual fraction were analyzed for each sample, allowing the study of behavior of U and Th in dynamic lixiviation conditions. Multivariate techniques have been employed for the efficient optimization of the independent variables that affect the lixiviation process. The system reached LODs of 0.1 and 0.7 ng kg−1 of U and Th, respectively. The method was satisfactorily validated for three solid matrices, by the analysis of a soil reference material (IAEA-375), a certified sediment reference material (BCR- 320 R) and a phosphogypsum reference material (MatControl CSN-CIEMAT 2008). Besides, environmental samples were analyzed, showing a similar behavior, i.e. the content of radionuclides decreases with the successive extractions. In all cases, the accumulative leached fraction of U and Th for different solid matrices studied (soil, sediment and phosphogypsum) were extremely low, up to 0.05% and 0.005% of U and Th, respectively. However, a great variability was observed in terms of mass concentration released, e.g. between 44 and 13,967 ng U kg−1.

This paper is the second chapter of a piece entitled “Low-level determination of Th-isotopes by alpha spectrometry”. This Part 2 presents the results of the analysis of the first and last steps for Th-isotopes determination by alpha-particle spectrometry: the sample pre-treatment, total dissolution following different methods and lixiviation, and the test sample preparation methods, electrodeposition and microprecipitation, together with a brief analysis of the financial costs of the analyzed methods.

Thorium is an unusual radionuclide in laboratory intercomparisons and when it appears, the number of participants providing results is small and the results provided are not reliable enough. These facts are particularly significant for environmental and industrial solid samples. In this work, we analyze the most suitable method for Th determination by alpha-particle spectrometry, evaluating technical points and also considering cost, time and chemical reagents used. This work is divided in two parts. This part 1 deals with the analysis of different radiochemical separation methods for Th isotopes.

This study examined the 238Pu and 239+240Pu activity concentration and the 240Pu/239Pu atomic ratio in peat bogs sampled in 2012 from marshlands in central Madagascar. The purpose was to investigate the presence of plutonium isotopes, 238, 239, 240Pu, from the 1964 satellite failure carrying a SNAP-9A radiothermal generator. With an average 238Pu/239+240Pu activity ratio of 0.165 ± 0.02 (decay corrected to 1964), the peat bogs in Madagascar exhibit similar values as the ones found in the southeastern African continent, except they are one order of magnitude higher than expected (0.025) from global fallout in the Southern Hemisphere. The 240Pu/239Pu atomic ratio showed a distinct decrease for layers dating back to the mid-1960s (down to 0.069 compared with an anticipated ratio of 0.17 for global fallout), indicating that the SNAP-9A failure also resulted in an elevated deposition of 239Pu. The obtained results demonstrate that further Pu analysis in Madagascar and in southeastern continental Africa is necessary to fully account for the regional Pu deposition from the SNAP-9A event., This study was in part financed by grants (e.g. SSM2007_2984_32) by the Swedish Radiation Protection Authority (SSM), Sweden.

The release of 226Ra from phosphogypsum (PG) was evaluated by developing a novel tool for fully automated 226Ra lixiviation from PG integrating extraction/pre-concentration using a renewable sorbent format. Eight leached fractions (30mL each one) and a residual fraction were analyzed allowing the evaluation of dynamic lixiviation of 226Ra. An automatic system allows this approach coupling a homemade cell with a 226Ra extraction/pre-concentration method, which is carried out combining two procedures: Ra adsorption on MnO2 and its posterior co-precipitation with BaSO4. Detection was carried out with a low-background proportional counter, obtaining a minimum detectable activity of 7Bqkg-1. Method was validated by analysis of a PG reference material (MatControl CSN-CIEMAT 2008), comparing the content found in fractions (sum of leached fractions + residual fraction) to the reference value. PG samples from Huelva (Spain) were studied. 226Ra average activity concentration of the sum of leached fractions with artificial rainwater at pH 5.4±0.2 was 105±3Bqkg-1d.w. representing a 226Ra lixiviation of 37%; while at pH 2.0±0.2, it was 168±3Bqkg-1 d.w., which represents a 50%. Also, static lixiviation, maintaining the same experimental conditions, was carried out indicating that, for both considered pH, the 226Ra release from PG is up to 50% higher in a dynamic leaching that in a static one, may have both environmental and reutilization implications.

A new carbon mineralization method was designed based on a sequestration agent synthesised exclusively from industrial wastes. Phosphogypsum waste from the fertiliser industry was dissolved into caustic aqueous waste from the aluminium anodising industry. The resulting precipitate consisted of katoite (Ca3Al2(OH)12, a Si-free hydrogrossular solid solution end-member of the Al-containing hydrogarnet) and thenardite (Na2SO4); the latter easily removed by rinsing with water. The carbonation performance of this katoite-rich sequestration agent was evaluated using two different methods, by bubbling in aqueous media and by weathering. Both procedures yielded high carbonation efficiencies (80% and 100%, respectively), and resulted in a solid precipitate composed primarily of calcite (CaCO3) and aluminium hydroxide (Al(OH)3). Priority attention was given to the transfer of trace elements and radionuclides of the uranium series typically present in the phosphogypsum. Results confirmed that the traces were transferred to resulting final solid carbonate at concentrations similar to those present in the raw phosphogypsum. In conclusion, these carbonated minerals would trap substantial amounts of CO2 and produce final materials with similar civil engineering uses to those proposed for current phosphogypsum wastes. This work offers new methods for jointly managing specific industrial wastes oriented to more sustainable industrial processes and controlling CO2 emissions

The paper is a collective effort of participants in IAEA's CRP K41016 and their respective teams., The 210Pb sediment dating is the most widely used method to determine recent (~100–150 years) chronologies and sediment accumulation rates in aquatic environments and has been used effectively for reconstruction of diverse environmental processes associated with global change. Owing to the relative accessibility of the 210Pb methodology, many environmental chronologies have been produced, but not always critically assessed. Sometimes, sedimentary processes such as compaction, local mixing, erosion, or episodic sedimentation are not taken into account, nor the validity of the fundamental premises and proper estimation of uncertainties assessed. A Pb-210 dating interlaboratory comparison modelling exercise was designed within the framework of the IAEA (International Atomic Energy Agency) Coordinated Research Project “Study of temporal trends of pollution in selected coastal areas by the application of isotopic and nuclear tools” (CRP K41016), to identify potential problems associated with the use of 210Pb dating models and to suggest best practices to obtain reliable reconstructions. The exercise involved 14 laboratories worldwide with different levels of expertise in the application of the 210Pb dating methods. The dating exercise was performed using 210Pb, 226Ra and 137Cs activity data from two sediment cores (coastal and lacustrine sediments), and the participants were requested to provide their 210Pb chronologies based on dating models. This modelling exercise evidenced the limitations and constraints of 210Pb method when supplementary and validation information is not available. The exercise highlighted the relevance of solid understanding of the fundamentals, assumptions and limitations of the 210Pb dating method and its validation, and allowed identifying key aspects to improve the reliability of 210Pb dating process, including: a critical examination and interpretation of the 210Pb activity depth profile; an appropriate selection of the 210Pb dating model according to the characteristics of the 210Pb activity profile and the environmental setting taking into account sediment compaction in the calculations; a sound identification of the 210Pb equilibrium depth and the estimation of the 210Pb inventory ensuring the best possible estimation of interpolated 210Pb values when needed; and the use of independent markers to corroborate the age models., The IAEA is grateful to the Government of the Principality of Monaco for the support provided to its Environment Laboratories. This work has been supported by the IAEA Coordinated Research project “Study of Global Temporal Trends of Pollution in Selected Coastal Areas by the Application of Isotopic and Nuclear Tools” (CRP K41016).

This paper presents the levels and distribution of 210Po in different compartments of a coastal lagoon on the east coast of Uruguay (South America). Activity concentrations of 210Po have been obtained in different matrices, such as water, superficial sediments, clams (Diplodon sp.), freshwaters snails (Pomacea sp.), zooplankton, and fishes (Jenynsia sp.), collected at different points of the lagoon and during several sampling campaigns. In addition, the organic matter content of the sediment was determined to study the variation of 210Po along the lagoon. The activity concentrations of 210Po in the water samples are in the range between 1.1 ± 0.2–3.5 ± 0.4 mBq/L while in the sediment samples vary between 17.1 ± 1.4 and 540 ± 12 Bq/kg, DW. In the case of biota, the ranges obtained were 182 ± 5–265 ± 6 Bq/kg, DW in clams and 134 ± 4–1245 ± 16 Bq/kg, DW in snail samples. A good correlation of 210Po with the organic fractions of the sediment was observed (r = 0.8798, p-value < 0.001), being obtained high values for the distribution coefficient Kd (104 -105). In the biota samples, a clear difference was observed in the 210Po concentration values in both species, mainly due to the different feeding habits of both aquatic organisms, as it is reflected in the associated concentration ratios (CR). In this paper, a good set of results of 210Po, Kd, and CR have been obtained in different matrices, enhancing the limited archives available for modelers concerning these parameters for 210Po and freshwater systems., This work was supported by National Agency for Research and Innovation (ANII) through PhD (POS_NAC_2016_1_130091) and movility fellowships (MOV_CA_2019_1_156608), and Comisión Sectorial de Investigación Científica (CSIC), and Programa de Desarrollo de las Ciencias Básicas (PEDECIBA).

Next to the city of Huelva (SW of Spain), around 100 Mt of phosphogypsum (PG) are stored in stacks on the salt-marshes of the Tinto River estuary covering a surface of about 1000 ha. Due to the high content of 238U series natural radionuclides of the PG, its acidic nature (pH about 3), and the fact that PG stacks were disposed without any kind of isolation from the substrate, they could produce a potential radioactive impact into the underlying sediments. The aim of this work is to assess the pollution of the underlying sediments by natural radionuclides coming from the PG stacks. To this end, seven cores were taken, and PG and sediments samples collected at different depths were analysed. The activity concentrations of the main long half-live natural radionuclides of interest were determined by applying both gamma-ray and alpha-particle spectrometry radiometric techniques. The results of this study showed that the first decimeters of salt-marsh sediment act as a “barrier” for the radionuclides coming from the PG stacks decreasing rapidly its activity concentration in depth, affecting mainly sediments located in the first 20 cm below the contact due to mixing processes. While 230Th, 226Ra and 210Pb pollution is mainly restricted to the first 20 cm of sediments, U-isotopes can reach higher depths (up to around 50 cm) by leaching processes due to their lower reactivity and higher concentration in the polluted leachates. The obtained results have high relevance for the design of the perimeter channel which is projected to build in the restoration project, suggesting that should has around 1 m deep under the base of the PG stacks, to ensure the full collection of polluting leachates, and to prevent their release into the estuary of the Tinto River.

This paper reports concentrations of γ-emitter radionuclides (40K, 137Cs, 210Pb, 226Ra, 228Ra, 228Th and 234Th) and some metals (Al, Cr, Fe, Co, Ni, Cu, Zn, As, Sr, Cd, Sb, Cs, Pb, Th and U) in surficial sediments from the Ankobra, Pra and Volta estuaries, in Ghana. Artisanal gold-mining in the Ankobra and Pra basins promoted moderate enrichments of As, Sb, Cu, Cs and Cr in their estuarine sediments, with respect to the reference background of the Volta Estuary. Radionuclide concentrations were in the range found in the Earth's crust. Present data do not support any conclusion on their potential enrichments due to gold-mining activities. Radionuclide isotopic ratios revealed a transfer of 228Ra from sediments to the water column. Pearson correlation coefficient matrices showed different patterns, which were reasonably understood after novel approaches: i) inter-estuaries comparison of slopes in the linear regressions of element-concentrations vs Al, Fe and Cs; ii) study of Al-normalized concentrations of elements; iii) excess 210Pb informing on local sedimentary conditions. The metal enrichments observed in the Ankobra and Pra estuaries are associated with the Fe-rich compounds in sulphide ores (such as FeAsS) transported along the river course and deposited in the estuary., The authors extend gratitude to the International Atomic Energy Agency (IAEA) for supporting the Regional Project RAF7009 and the fellowship GHA-16025.

Radiocarbon (14C) measurements of foraminifera are often challenging as their reliability and accuracy can be biased by several complicating factors. In this work, at the Centro Nacional de Aceleradores (CNA) in Seville, an automated setup with a Carbonate Handling System coupled with an automated graphitization system has been tested to investigate the potential for running samples of foraminiferal carbonate for AMS 14C dating of marine archives. The reproducibility of 14C ages for blanks and standard materials indicates that reliable 14C analyses are possible for carbonate samples with a 14C age up to 50,000 yr BP. With this automated procedure we were able to date monospecific planktonic foraminifera younger than 1000 yr BP. Biological mixing and high sedimentation are potentially complicating mechanisms resulting in anomalous young 14C ages in planktonic foraminifera from the deep Mediterranean Sea., The research leading to these results was supported by the European Science Foundation (ESF) Exchange Visit Grant 5103 ‘Dating and TIming of fluxes into and out of the MarinE CArbon Reservoir of the MeDiterranean Sea (TIMECARD)’ under the Research Networking Programme Earthtime – The European Contribution (EARTHTIME-EU). We are deeply indebted to Leonardo Langone from the CNR-ISMAR for providing the planktonic foraminifera samples along with numerous geochemical proxies used to interpret data from this study.

After the Fukushima accident, large amounts of radionuclides were discharged to the atmosphere. Some of them travelled long distances and were detected in places as far from Japan as Spain a few days after the accident. One of these radionuclides was I. Its isotope I (T1/2 = 15.7 × 106 years) was also expected to follow the same pathway. In this work, we present the results for the I concentration in the same atmospheric samples from Seville (Spain) where I activity was measured in 2011 by Baeza et al. (2012). I concentrations in aerosol and gaseous samples showed concentrations in the order of 104 and 105 atoms/m, typically higher in the gaseous form with respect to the aerosol form. Also I in rainwater was measured, showing concentrations in the order of 10 atoms/L. The results show a very good agreement with the I profile, showing that, if background from other sources is not relevant, it is possible to estimate the impact of similar events years after them thanks to the sensitivity of techniques like Accelerator Mass Spectrometry., This work has been financed by the project P10-FQM-5956 by the Junta de Andalucía and the projects FIS2012-31853 and FIS2015-69673-P by the Spanish Ministerio de Economía and Competitividad.

Accelerator mass spectrometry and benzene synthesis coupled with liquid scintillation spectrometry are often used for accurate measurements of 14C activity in the environmental matrices. Thermal oxidation is one of the methods employed for 14C determination in environmental matrices. In this method, the sample is oxidised at high temperature (600–900 °C) to convert carbon species to CO2 and trapped in an amine-based absorber for determining the activity in a liquid scintillation counting (LSC) system. In this study, the performance of a commercially available tube furnace system (pyrolyser), for batch combustion of samples, was evaluated for the determination of 14C specific activity in terrestrial biota samples. Significant improvements over the manufacturer specified method, which is primarily designed for analysis of samples with activity well above the environmental background level, was implemented to achieve accurate determination of 14C specific activity at ambient background level. In the improved method, the CO2 produced from the combustion of the sample was isolated from the combustion products through cryogenic trapping and then absorbed in the absorber (Carbo-Sorb E) through a simple off-line transfer process. This allowed (i) optimisation of CO2 absorption by the absorber (2.2477 g of CO2/10 mL), (ii) achieving good accuracy and precision in the measurements, and a minimum detectable activity value of 13 Bq kg−1C for a counting time of 300 min (7 Bq kg−1C for 1000 min), (iii) avoiding uncertainty associated with the determination of recovery of 14C in the combustion and trapping process, and (iv) elimination of the need for an independent determination of carbon content (%) for expressing the results in terms of 14C specific activity. The method is capable of yielding accurate results with a deviation of, The authors would like to thank the Board of Research in Nuclear Science (BRNS, DAE, Govt. of India, for funding the research programme (BRNS sanction no. 2013/36/22-BRNS/3341 dated 18.03.2014). The authors would like to thank Shri. H. S. Kushwaha, Outstanding Scientist, BARC, Mumbai, and Dr. D Roy, Programme Officer, BRNS for their comments and suggestions. Thanks are due to Sri B N Dileep, Officer-in-charge, Environmental Survey Laboratory, and many officials and scientists of Kaiga Generating Station, Kaiga for extending logistical support for this study. Thanks are due to Dr Reshmi T.R and Dr Sudeesh, Isotope Hydrology Division, Centre for Water Resources Development and Management, Kozhikode, Kerala for isotope ratio measurements.

Theoretical and experimental studies have shown that activity concentrations of fallout radionuclides (such as 137Cs and excess 210Pb) decrease with particles size in aqueous suspensions. This paper is aimed at reviewing the theoretical fundamentals for granulometric speciation of radionuclides, and at exploring its practical use in the analytical context of gamma spectrometry for the radiometric dating of recent sediments, with view to: i) improving the detection of 137Cs (since its use as independent chronostratigraphic mark is challenging in the southern hemisphere because its low fallout rate), ii) supporting refined CIC models and normalization techniques in 210Pb-based radiogeochronologies. The work uses surface sediments sampled from the Tinto Estuary (SW Spain), affected by mining and phosphate-fertilizer industries, and from the Ankobra Estuary (Ghana), affected by intensive artisanal gold-mining. Granulometric classes have been separated by a sieving column with decreasing mesh sizes and the obtained cumulative percentage of mass mathematically described by a Rosin-Rammler particle-size distribution. The target radionuclides for gamma spectrometry were 210Pb, 226Ra and137Cs, complemented with 40K, 234Th and 228Ra. Results revealed that, far from ideal experiments, under actual environmental conditions the increase in activity concentrations with decreasing particle sizes is too moderate, and in general they are affected by larger counting uncertainties due to the small available amount of mass. Indeed, there was no correlation between grain-size and 137Cs concentrations (p = 0.25), and similarly for excess 210Pb (p = 0.53). No effect of the organic matter content was observed in 137Cs (p = 0.58) and excess 210Pb (p = 0.85) concentrations. Present results pose some concerns to the general use of granulometric speciation in the context of gamma spectrometry for supporting the radiometric dating of recent sediments. A detailed discussion on the use of normalization methods is also presented., The authors would like to extend gratitude to the International Atomic Energy Agency (IAEA) for supporting the Regional Project RAF7009 and the fellowship GHA -16025.

The development of an environmental program on NORM radionuclides in former mining areas in Sweden implied the assessment of alpha emitter elements (U, Th and Po) measured for the first time in a Laboratory in different matrices. The first stage of this program is devoted to the Quality Assurance. The present work shows one way to apply inner Control Tests to produce reliable results based on (a) the combination of different techniques (alpha vs. Gamma spectrometry, alpha spectrometry vs. ICP-MS or gamma spectrometry vs. XRF) and (b) on the performance of intercomparison exercises with another laboratory with a wider experience in the field. After a positive feedback in these previous steps, the laboratory took part in an external validation exercise: IAEA Proficiency test in 2015 with a good degree of performance. In conclusion, a laboratory starting with radiometrical techniques based on alpha spectrometry can develop its own inner quality control program with the main aim to enhance the Quality Assurance of the delivered results without using reference material and based on regular samples results. This goal is achieved mainly via internal validation exercises and the final competence is gained through regular participation in external validation exercises (IAEA, Almera network or European Commission’s Joint Research among others)., Financial support of the project “Behaviour of Natural radionuclides in Pit lakes in Sweden” (SSM2014-3485) is deeply indebted to the Swedish Radiation Safety Authority (SSM).

Knowledge of accurate radio-isotopic signatures and chemical constituents is essential in assessing potential radiological hazards to the public and workers from exposure to NORM waste. For that reason, scale and sludge samples from Ghanaian oilfields were assessed using alpha spectrometry, gamma spectrometry, radon monitoring and scanning electron microscope techniques. Activity concentration of 238U, 232Th-series and 40K radionuclides for NORM residues have been evaluated. Fourteen trace elements were also identified and semi-qualitatively quantified. The obtained results clearly reflect that scale and sludge may present radiological risk for workers, public and environment.

This paper shows the studies carried out in Palomares (Almería, Spain) following the ground dispersion of nuclear material as a result of the air crash accident that took place in 1966, in which four nuclear bombs were involved. As a consequence of the Palomares accident, plutonium (Pu) and uranium (U) were dispersed over an area of approximately 2.3 km2 due to the chemical explosion of two of them. The most relevant activities carried out by CIEMAT, along with other national and international institutions in the Palomares scenario are detailed. These activities, performed for over 50 years, focus mainly in the characterization of the contamination source, in the continuous environmental and personal radiological monitoring programs, in the construction of a detailed superficial and 3-D mapping distribution of the remaining contamination and in the evaluation of the bioavailability of the transuranics still remaining in the area., This work was supported by CIEMAT (Spanish the Ministry of Science, Innovation and Universities under the General Secretariat for Scientific Policy Coordination).

Made available in DSpace on 2019-10-06T16:04:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Barreiro area at Araxá city, Minas Gerais State, Brazil, has been subjected to intense debate because of environmental pollution related to intense mining activities developed for the phosphate and niobium exploitation. Anthropogenic inputs involving the barium release into waters occurred there by the early 1980s because of a leakage occurring at one tailings dam as the adoption of synthetic membrane for the dam waterproofing only started in 2006. This paper reports a novel (radio)chemical record obtained from the analysis of samples of waters and a 35-cm depth sediment core with the aim of focusing the major pathways for the constituents transport there, which are accompanied by information on possible modifications along the time as provided by the use of the 210Pb chronological method. All waters are reducing, despite the rainwater is acid and the remaining (surface water and groundwater) are alkaline. Calcium dominates the rainwater composition, whereas Si is a relevant constituent in the surface and groundwater samples. The sediments are classified as silty sand and sand, Fe2O3 is the major oxide of all sediments sections, reaching a mean concentration value of 47% and it is followed by Organic Matter > BaO > SiO2 > P2O5 > Al2O3 > TiO2 > SO3 > CaO > Nb2O5 whose mean concentration is between 2 and 15%. The Ba levels in waters and sediments from Barreiro area are high, unlike in other streams draining the Araxá municipality. Chloride exhibited a high mobility index, confirming its conservative behavior in solution, whereas the quite low value for iron corroborates that Fe oxides/hydroxides are highly sorptive materials. The CRS 210Pb chronological model allowed identify BaO, Nb2O5, SO3, ThO2 and REEs (La, Ce) concentration peaks around 1973, agreeing with the significant correlations found among these parameters. Departamento de Petrologia e Metalogenia Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178 Departamento de Física Aplicada II Universidad de Sevilla, Av. Reina Mercedes No. 2 Departamento de Petrologia e Metalogenia Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178 CNPq: 400700/2016-6

Cosmogenic radionuclides in the one-million-year half-life range, like 10Be, find application fields in several Sciences. They are powerful tools in Geology and Geochronology, as they are very important tracers on the Earth, being utilized as chronometer. Meteoric 10Be (T1/2 = 1.39 × 106 y) associated to aerosols can be used as a tracer of atmospheric processes and specifically as indicators of the cosmogenic interactions in lower Stratosphere, upper Troposphere, the air exchange between both and deposition processes on the Earth surface. The applications of 10Be are even more relevant when combined with other radionuclides such as 26Al. In order to provide new data about concentration 10Be in this type of samples, the first atmospheric air filters in Spain have been analysed. Values around 104 at/m3 (atoms per cubic meter of air) for 10Be have been obtained. Due to the location and the features of the sampling site (urban area, at sea level and mid latitude), a new radiochemical procedure was designed and developed in our laboratory for the Accelerator Mass Spectrometry (AMS) measurement of 10Be in this kind of samples. The samples were measured in SARA, the 1 MV AMS system at Centro Nacional de Aceleradores (CNA)., This work has been financed through the projects FIS2012-31853 and FIS2015-69673-P provided by the Spanish Ministry of Economy and Competitiveness.

International audience; 234Th measurements are widely used to estimate the downward carbon flux of particles via the oceanic Biological Pump. Carbon export is evaluated from 234Th-238U disequilibrium assuming either steady state (SS) conditions, or including a non-SS (NSS) correction. We use a novel stochastic simulation to quantify the temporal variation of vertical carbon and 234Th (dissolved and particulate) concentration profiles with high temporal resolution. We calculate seasonal export as if in situ measured with sediment trap and SS- and NSS-234Th approaches and quantify the periods of validity for SS/NSS conditions defined in previous works. The SS approach is valid throughout the entire season in oligotrophic regions. In temperate regions, the SS introduces a bias in the export if sampling takes place outside specific temporal windows. Windows of validity range from days in short blooms of 15-day duration to weeks in blooms longer than 30 days.

Produced water from two Ghanaian offshore production oilfields has been characterized using alpha spectrometry after radiochemical separation, non-destructive gamma spectrometry and ICP-MS and other complimentary analytical tools. The measured concentrations of main NORM components were in the range of 6.2-22.3 Bq.L, 6.4-35.5 Bq.L, and 0.7-7.0 Bq.L for Ra, Ra and Ra respectively. A good correlation between several physico-chemical parameters and radium isotopes was observed in each production oilfield. The radium concentrations obtained in this study for produced water from the two oilfields of Ghana are of radiological importance and hence there may be the need to put in place measures for future contamination concerns due to their bioavailability in the media and bioaccumulation characteristics. The results will assist in critical decision making for future set up of appropriate national guidelines for the management of NORM waste from the emerging oil and gas industry in Ghana., This work was funded by the International Atomic Energy Agency in the form of an 18 months Sandwich Fellowship and the Radiation Protection Institute of the Ghana Atomic Energy Commission (fellowship grant Number GHA/14019).

Proceedings of the 9th International Topical Meeting on Industrial Radiation and Radioisotope Measurement Applications, celebrado en Valencia (España) del 6 al 11 de julio de 2014., Industrial activities involving Naturally Occurring Radioactive Materials (NORM) are found among the most important industrial sectors worldwide as oil/gas facilities, metal production, phosphate Industry, zircon treatment, etc. being really significant the radioactive characterization of the materials involved in their production processes in order to assess the potential radiological risk for workers or natural environment. High resolution gamma spectrometry is a versatile non-destructive radiometric technique that makes simultaneous determination of several radionuclides possible with little sample preparation. However NORM samples cover a wide variety of densities and composition, as opposed to the standards used in gamma efficiency calibration, which are either water-based solutions or standard/reference sources of similar composition. For that reason self-absorption correction effects (especially in the low energy range) must be considered individually in every sample. In this work an experimental and a semi-empirical methodology of self-absorption correction were applied to NORM samples, and the obtained results compared critically, in order to establish the best practice in relation to the circumstances of an individual laboratory. This methodology was applied in samples coming from a TiO2 factory (NORM industry) located in the south-west of Spain where activity concentration of several radionuclides from the Uranium and Thorium series through the production process was measured. These results will be shown in this work., This research has been partially supported by the Spanish Nuclear Safety Council (Grant no. CSN 2004-001) through the project “Radiological Impact associated with Non-Nuclear Industries from South of Spain”, and by the Spanish Department of Science and Technology (Grant no. CTM 2009-14321-C02-01-02) through the Project “Determination of scavenging rates and sedimentation velocities using reactive particle radionuclides in coastal waters; application to pollutants dispersion”.

In this paper a call is performed in support of the valorization of some by-products generated in the production processes of some NORM industries. In spite of a traditional management of these by-products based either in their direct releases to the environment or their disposal under control in big areas, their use attending to their characteristics in fields as agriculture, construction of buildings, construction of roads, in landfills, etc. should be promoted. These applications will minimize the environmental and public radiological impact of these by-products, generating at the same time economic benefits to the NORM industries involved.

A radiological evaluation associated to the future mining of grey monazite nodules enriched in light rare-earths, from a modest superficial deposit located in the centre of Spain, has been performed at pre-operational level, and the main results are shown in this paper. Although the monazite nodules in the deposit are clearly enriched in radionuclides from the uranium and thorium series with activity concentrations higher than 1 Bq/g, the size of these nodules (in the 0.5 mm–2 mm grain size interval), its refractory behaviour that prevents the leaching or dissemination of natural radionuclides to waters or other ecosystem compartments and consequently the impact in the food chain, and its presence quite diluted in the deposit at concentrations of 2.5–3 kg/m3, conducted to conclude that pre-operationally the area to be mined for the extraction of the monazite is generating a negligible radiological impact in the public and the nearby environment. Additionally, the extraction of the raw material and the restoration of the area after mining (i.e. the mining activities which will be done in-situ, in the mining area) will be exempted of any radiological regulation attending to the European Union legislation being expected that will not generate a radiological impact.

The production of phosphate fertilizers usually uses as raw material sedimentary phosphate rock, which contains enhanced concentrations from U‐series radionuclides about 10–100 times higher than unperturbed soils. This fact implies the need for evaluating the radiological implications of this activity. In our case, the study has been performed in a large fertilizer industrial complex located at Huelva town (SW of Spain), where sedimentary phosphate rock has been processed since 1965 to 2010, generating annually an average of about 2.5 million tons of a by‐product called phosphogypsum (PG), which has been stored in big stacks 1 km away from Huelva city, covering 1000 ha. The fluxes of the radionuclides of interest along the production process and the effective doses received by the workers have been determined. In addition, the radioecological impact associated to the waste management strategy followed has been evaluated., This work was partially supported by the Ministry of Economy and Competitiveness of Spain through the research project with Ref.: CTM2015‐68628‐R.

An international conference on Radioecological Concentration Processes was held in Seville, Spain, 6–9 November 2016 at the Centro Nacional de Aceleradores. It was attended by 160 participants from 35 different countries. This was the 2nd conference on this item since 1966, 50 years ago. The conference covered aspects of radiological important radionuclides on terrestrial, marine and freshwater environments and has allowed obtaining a clear picture of the status of the Radioecology as a consolidated discipline in the 21st century.

Phosphogypsum (PG) is a waste product of the phosphoric acid production process and contains, generally, high activity concentrations of uranium series radionuclides. This study is a contribution towards a risk assessment in areas affected by phosphate industry in SW Spain, integrating information from soil physicochemical characteristics, total and soluble potentially toxic elements (Zn, Pb, Cd, Cu, As and Fe), mineralogical composition and ecotoxicological evaluation. The applied bioassays confirmed the soil toxicity categorisation and then, it is highly recommended to complement the results from environmental chemistry with results from bioassays, in order to provide a more complete and relevant information on the bioavailability of contaminants and to characterise the risk of contaminated areas.

The biological carbon pump (BCP) transfers carbon from the surface ocean into the oceans' interior, mainly in the form of sinking particles with an organic component, and thereby keeps atmospheric CO2 at significantly lower levels than if the oceans were abiotic. The depth at which these sinking particles are remineralized is a key control over atmospheric CO2. Particle sinking speed is likely to be a critical parameter over remineralization depth. Carbon export is usually controlled by large, rapidly sinking particles (>150 m·d−1); however, under some circumstances sinking velocity distributions are strongly bimodal with a significant fraction of total flux being carried by slowly (

Radiometric determinations have been carried out to assess public exposure to radioactivity for communities along the coast of a shallow water offshore oilfield in Ghana (which started their operations recently) in order to establish baseline data using alpha spectrometry after radiochemical separation and non-destructive gamma spectrometry. The average activity concentrations of (234)U, (238)U, (230)Th and (232)Th by alpha-particle spectrometry and of (226)Ra, (228)Ra, (228)Th, (40)K, (210)Pb, (234)Th and (137)Cs by gamma-ray spectrometry were determined in the soil samples. The activity concentrations of (234)U, (238)U, (230)Th and (232)Th were determined in the water samples by alpha-particle spectrometry and of (226)Ra by liquid scintillation counting. The total annual effective dose to the public was estimated from the measured activity concentrations and this was clearly below the International Commission on Radiological Protection (ICRP) reference level of 1 mSv y(-1) for public exposure control. In addition, the estimated values of Raeq, Hex and Hin were all lower than the recommended acceptable values and the mean values of gross alpha and gross beta determinations performed for all the water samples give values that were all below the Ghana Standards Authority and World Health Organization recommended guideline values for drinking water quality. The results obtained show insignificant public exposure to radioactivity. However, this study provides important information for future studies on subsequent evaluations of the possible future environmental contamination due to activities of the oil industry in Ghana.

Titanium is a very important element for several industrial applications, being one of the ninth most abundant elements in the Earth’s crust (0.63% wt). In this work it will discuss the different mining and industrial activities involved in the production of titanium dioxide. The first step analyzed will treat about the beneficiation mining process of titanium mineral, and secondly, it will discuss the two main processes of the TiO2 manufacturing (sulphate and chloride routes). In addition, we will show different uses of the titanium dioxide pigment as filler in paper, plastics and rubber industries and as flux in glass manufacture, etc. Finally, we will show that the old wastes are currently called co-products since they were valorized, being commercialized by the Spanish industry of TiO2 production in different fields such as agriculture, civil engineering, or cement manufacturing.

210Pb and 7Be activity concentrations in surface air and in bulk deposition have been measured from November 2009 to December 2011 along the Gulf of Cadiz (Southwest of Spain). This area presents mesoscale variations in its meteorological conditions, with influence of air masses with different origins: maritime, either from the Atlantic Ocean or the Mediterranean Sea and continental, from Iberian Peninsula and north of Africa, which make possible this region to be suitable to analyse the mesoscale spatial and temporal variations of atmospheric compounds. The objective of this study is to determine if there are differences in 210Pb and 7Be activity concentrations in surface air and in bulk deposition at the mesoscale level in this complex area of southwestern Iberian Peninsula taking as reference two sites of the same geographical area but influenced by different meteorological conditions. The temporal evolution pattern of PM10 was different for each site (no correlation between both series was found), but the PM10 average concentrations were similar for both locations (differences were not found at 0.05 significance level). On the other hand, the temporal evolution of 7Be and 210Pb activity concentrations in surface air show a good correlation between both sites, indicating this fact a similar behaviour of these radionuclides in the area. Finally, for each location a strong correlation between 210Pb and 7Be depositional fluxes was also observed, showing that wet deposition plays a key role in the deposition fluxes of both radionuclides. The averages depositional fluxes for 7Be and 210Pb are 750 Bq m−2 y−1 and 60 Bq m−2 y−1 in both locations, respectively. This set of results allows to determine that both radionuclides (7Be and 210Pb) present similar atmospheric behaviours, although with mesoscale variations in the magnitude of the values along the entire southern coast of the Iberian Peninsula.

The impact of the earthquake and tsunami on the east coast of Japan on 11 March 2011 caused a loss of power at the Fukushima Dai-ichi nuclear power plant (NPP) that resulted in one of the most important releases of artificial radioactivity into the environment. Although several works were devoted to evaluating the atmospheric dispersion of radionuclides, the impact of the discharges to the ocean has been less investigated. Here we evaluate the distribution of Fukushima-derived 90Sr (n = 57) and 89Sr (n = 19) throughout waters 30–600 km offshore in June 2011. Concentrations of 90Sr and 89Sr in both surface waters and shallow profiles ranged from 0.8 ± 0.2 to 85 ± 3 Bq m−3 and from 19 ± 6 to 265 ± 74 Bq m−3, respectively. Because of its short half-life, all measured 89Sr was due to the accident, while the 90Sr concentrations can be compared to the background levels in the Pacific Ocean of about 1.2 Bq m−3. Fukushima-derived radiostrontium was mainly detected north of Kuroshio Current, as this was acting as a southern boundary for transport. The highest activities were associated with near-shore eddies, and larger inventories were found in the closest stations to Fukushima NPP. The data evidence a major influence of direct liquid discharges of radiostrontium compared to the atmospheric deposition. Existing 137Cs data reported from the same samples allowed us to establish a 90Sr / 137Cs ratio of 0.0256 ± 0.0006 in seawater off Fukushima, being significantly different than that of the global atmospheric fallout (i.e., 0.63) and may be used in future studies to track waters coming from the east coast of Japan. Liquid discharges of 90Sr to the ocean were estimated, resulting in an inventory of 53 ± 1 TBq of 90Sr in the inshore study area in June 2011 and total releases of 90Sr ranging from 90 to 900 TBq, depending upon the reported estimates of 137Cs releases that are considered.

A study about the distribution of several radionuclides from the uranium and the thorium series radionuclides along the production process of a typical NORM industry devoted to the production of titanium dioxide has been performed. With this end the activity concentrations in raw materials, final product, co-products, and wastes of the production process have been determined by both gamma-ray and alpha-particle spectrometry. The main raw material used in the studied process (ilmenite) presents activity concentrations of around 300 Bq kg−1 for Th-series radionuclides and 100 Bq kg−1 for the U-series ones. These radionuclides in the industrial process are distributed in the different steps of the production process according mostly to the chemical behaviour of each radioelement, following different routes. As an example, most of the radium remains associated with the un-dissolved material waste, with activity concentrations around 3 kBq kg−1 of 228Ra and around 1 kBq kg−1 of 226Ra, while the final commercial products (TiO2 pigments and co-products) contain negligible amounts of radioactivity. The obtained results have allowed assessing the possible public radiological impact associated with the use of the products and co-products obtained in this type of industry, as well as the environmental radiological impact associated with the solid residues and liquid generated discharges.

This work analyzes and evaluates the main mechanical, elastic and thermodynamic properties of cements manufactured with different proportions of red gypsum (RG), a waste generated by the titanium dioxide industry. The results show that red gypsum can be used as a safe substitute for natural gypsum in the manufacturing of commercial cements with no reduction in quality. In addition, the mobility of the original pollutants in red gypsum is negligible in the cements made from this waste, with the quantities of leached pollutants similar to those measured in standard reference cements formed with natural gypsum.

Made available in DSpace on 2018-11-26T17:40:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Mining activities can increase the mobility of metals by accelerating the dissolution and leaching of minerals from the rocks and tailing piles to the environment and, consequently, their availability for plants and subsequent transfer to the food chain. The weathering of minerals and the disposal of coal waste in tailing piles can accelerate the generation of acid mine drainage (AMD), which is responsible for the higher dissolution of metals in mining areas. In this context, the behavior of U, Th and K in soils and sediment, and the transfer factor (TF) of U-238, U-234 and Po-210 for soybean, wheat, pine and eucalyptus cultivated around a coal mine in southern Brazil was evaluated. Alpha and gamma spectrometry were used for the measurements of the activity concentration of the radioelements. Po-210 was the radionuclide that is most accumulated in the plants, especially in the leaves. When comparing the plant species, pine showed the highest TF values for U-234 (0.311 +/- 0.420) for leaves, while eucalyptus showed the highest TF for U-238 (0.344 +/- 0.414) for leaves. In general, TF were higher for the leaves of soybean and wheat when compared to the grains, and grains of wheat showed higher TF for Po-210 and U-238 than grains of soybean. Deviations from the natural U isotopic ratio were recorded at all investigated areas, indicating possible industrial and mining sources.of U for the vegetables. A safety assessment of transport routes and accumulation of radionuclides in soils with a potential for cultivation is important, mainly in tropical areas contaminated with solid waste and effluents from mines and industry. (C) 2017 Elsevier Ltd. All rights reserved. Univ Estadual Paulista, Dept Petrol & Metalogenia, UNESP, Campus Rio Claro,Av 24-A 1515, BR-13506900 Rio Claro, SP, Brazil Univ Seville, Dept Fis Aplicada 2, Av Reina Mercedes 2, E-41012 Seville, Spain Univ Estadual Campinas, Inst Geociencias, R Joao P Calogeras 51, BR-13083870 Campinas, SP, Brazil Univ Estadual Paulista, Dept Petrol & Metalogenia, UNESP, Campus Rio Claro,Av 24-A 1515, BR-13506900 Rio Claro, SP, Brazil CNPq: 203716/2014-0 CNPq: 168677/2014-8

In this work the 210Po activity concentrations determined in the most common marine species consumed by the population of Southern Spain are shown and discussed. The determinations have been done on aliquots of the raw edible materials and in aliquots previously cooked in the usual way they are ingested. The obtained activity concentrations in the edible parts of the cooked products ranged up to three orders of magnitude with concentration factors for some species as high as 104-105 L/kg fresh weight, and due to the cooking processes in some cases a considerable variation in the 210Po activity concentrations have been observed in relation with the determined ones in the aliquots not processed. The importance of this study is based in the fact that 210Po is one of the main contributors to the radiation dose received by the population by ingestion, being the 210Po doses by ingestion particularly high when a population has a diet with a high proportion of marine products.