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https://www.readbyqxmd.com/read/28343275/potential-toxic-elements-in-stream-sediments-soils-and-waters-in-an-abandoned-radium-mine-central-portugal
#1
I M H R Antunes, A M R Neiva, M T D Albuquerque, P C S Carvalho, A C T Santos, Pedro P Cunha
The Alto da Várzea radium mine (AV) exploited ore and U-bearing minerals, such as autunite and torbernite. The mine was exploited underground from 1911 to 1922, closed in 1946 without restoration, and actually a commercial area is deployed. Stream sediments, soils and water samples were collected between 2008 and 2009. Stream sediments are mainly contaminated in As, Th, U and W, which is related to the AV radium mine. The PTEs, As, Co, Cr, Sr, Th, U, W, Zn, and electrical conductivity reached the highest values in soils collected inside the mine influence...
March 25, 2017: Environmental Geochemistry and Health
https://www.readbyqxmd.com/read/28342344/water-hardness-determines-226-ra-uptake-in-the-tropical-freshwater-mussel
#2
Che Doering, Andreas Bollhöfer
Chemical data for freshwater mussels (Velesunio spp.) and water from 15 sampling sites in the Alligator Rivers Region and Rum Jungle uranium provinces in tropical Northern Australia were analysed to develop a predictive model of radium-226 ((226)Ra) bioaccumulation for variable water calcium (Ca) and magnesium (Mg) concentrations. Application of the model as a (226)Ra screening approach for freshwater mussels in tropical waterbodies potentially impacted by operational or remediated uranium mine sites is discussed in relation to Mudginberri Billabong, located approximately 12 km downstream of Ranger uranium mine in the Alligator Rivers Region...
March 22, 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/28342327/influence-of-terrestrial-radionuclides-on-environmental-gamma-exposure-in-a-uranium-deposit-in-para%C3%A3-ba-brazil
#3
José Araújo Dos Santos Júnior, Romilton Dos Santos Amaral, Rômulo Simões Cezar Menezes, Juan Reinaldo Estevez Álvarez, Josineide Marques do Nascimento Santos, Zahily Herrero Fernández, Jairo Dias Bezerra, Alberto Antônio da Silva, Kennedy Francys Rodrigues Damascena, José de Almeida Maciel Neto
One of the main natural uranium deposits in Brazil is located in the municipality of Espinharas, in the State of Paraíba. This area may present high levels of natural radioactivity due to the presence of these radionuclides. Since this is a populated area, there is need for a radioecological dosimetry assessment to investigate the possible risks to the population. Based on this problem, the objective of this study was to estimate the environmental effective dose outdoors in inhabited areas influenced by the uranium deposit, using the specific activities of equivalent uranium, equivalent thorium and (40)K and conversion factors...
March 22, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28340370/validation-of-comet-assay-in-oregon-r-and-wild-type-strains-of-drosophila-melanogaster-exposed-to-a-natural-radioactive-environment-in-brazilian-semiarid-region
#4
Cícero Jorge Verçosa, Aroldo Vieira de Moraes Filho, Ícaro Fillipe de Araújo Castro, Robson Gomes Dos Santos, Kenya Silva Cunha, Daniela de Melo E Silva, Ana Cristina Lauer Garcia, Julio Alejandro Navoni, Viviane Souza do Amaral, Claudia Rohde
Natural radiation of geological origin is a common phenomenon in Brazil, a country where radioactive agents such as uranium may be often found. As an unstable atom, uranium undergoes radioactive decay with the generation of a series of decay by-products, including radon, which may be highly genotoxic and trigger several pathological processes, among which cancer. Because it is a gas, radon may move freely between cracks and gaps in the ground, seeping upwards into the buildings and in the environment. In this study, two Drosophila melanogaster Meigen (Diptera, Drosophilidae) strains called Oregon-R and Wild (collected in a non-radioactive environment) were exposed to atmospheric radiation in the Lajes Pintadas city, in the semiarid zone of northeastern Brazil...
March 21, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28338312/engineering-nanoscale-iron-oxides-for-uranyl-sorption-and-separation-optimization-of-particle-core-size-and-bilayer-surface-coatings
#5
Wenlu Li, Lyndsay D Troyer, Seung Soo Lee, Jiewei Wu, Changwoo Kim, Brandon J Lafferty, Jeffrey G Catalano, John D Fortner
Herein, we describe engineered superparamagnetic iron oxide nanoparticles (IONPs) as platform materials for enhanced uranyl (UO22+) sorption and separation processes under environmentally relevant conditions. Specifically, monodispersed 8-25 nm iron oxide (magnetite, Fe3O4) nanoparticles with tailored organic acid bilayered coatings have been systematically evaluated and optimized to bind, and thus remove, uranium, from water. The combined non-hydrolytic synthesis and bilayer phase transfer material preparation methods yield highly uniform and surface tailorable IONPs, which allow us to directly evaluate the size-dependent and coating-dependent sorption capacities of IONPs...
March 24, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28335450/assessment-of-radioactive-materials-and-heavy-metals-in-the-surface-soil-around-the-bayanwula-prospective-uranium-mining-area-in-china
#6
Haribala Bai, Bitao Hu, Chengguo Wang, Shanhu Bao, Gerilemandahu Sai, Xiao Xu, Shuai Zhang, Yuhong Li
The present work is the first systematic and large scale study on radioactive materials and heavy metals in surface soil around the Bayanwula prospective uranium mining area in China. In this work, both natural and anthropogenic radionuclides and heavy metals in 48 surface soil samples were analyzed using High Purity Germanium (HPGe) γ spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS). The obtained mean activity concentrations of (238)U, (226)Ra, (232)Th, (40)K, and (137)Cs were 25.81 ± 9...
March 14, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28333049/uranium-biosorption-from-aqueous-solution-by-the-submerged-aquatic-plant-hydrilla-verticillata
#7
Zheng-Ji Yi, Jun Yao, Mi-Jia Zhu, Hui-Lun Chen, Fei Wang, Xing Liu
The biosorption characteristics of U(VI) from aqueous solution onto a nonliving aquatic macrophyte, Hydrilla verticillata (dry powder), were investigated under various experimental conditions by using batch methods. Results showed that the adsorption reached equilibrium within 60 min and the experimental data were well fitted by the pseudo-first-order kinetic model. U(VI) adsorption was strongly pH dependent, and the optimum pH for U(VI) removal was 5.5. Isotherm adsorption data displayed good correlation with the Langmuir model, with a maximum monolayer adsorption capacity of 171...
March 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28332833/uranyl-peroxide-clusters-incorporating-iron-trimers-and-bridging-by-bisphosphonate-and-carboxylate-containing-ligands
#8
Jie Qiu, Sining Dong, Jennifer E S Szymanowski, Malgorzata Dobrowolska, Peter C Burns
A hybrid uranium-iron cage nanocluster, [(UO2)24(FeOH)24(O2)24(PO4)8(CH(COO)(PO3)2)24](96-) (U24Fe24), was synthesized using bridging ligands containing bisphosphonate and carboxylate groups. U24Fe24 contains six tetramers of uranyl hexagonal bipyramids and eight iron trimers, each of which consists of three corner-sharing Fe(3+) octahedra and is stabilized by in situ formed phosphate and 2,2-bis(phosphonato)acetate (C2P2) groups. Tetramers and trimers are bridged by 24 C2P2 groups into a cage cluster. Crystals of U24Fe24 present a paramagnetic-like behavior...
March 23, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28332830/performance-and-mechanism-of-uranium-adsorption-from-seawater-to-polydopamine-inspired-sorbents
#9
Fengcheng Wu, Ning Pu, Gang Ye, Taoxiang Sun, Zhe Wang, Yang Song, Wenqing Wang, Xiaomei Huo, Yuexiang Lu, Jing Chen
Developing facile and robust technologies for effective enrichment of uranium from the seawater is of great significance for resource sustainability and environmental safety. By exploiting the mussel-inspired polydopamine (PDA) chemistry, diverse types of PDA-functionalized sorbents including magnetic nanoparticle (MNP), ordered mesoporous carbon (OMC) and glass fiber carpet (GFC) were synthesized. The PDA functional layers with abundant catechol and amine/imine groups provided an excellent platform for the binding to uranium...
March 23, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28330357/the-effect-of-symmetry-on-the-u-l3-nexafs-of-octahedral-coordinated-uranium-vi
#10
Paul S Bagus, Connie J Nelin, Eugene S Ilton
We describe a detailed theoretical analysis of how distortions from ideal cubic or Oh symmetry to tetrahedral, D4h, symmetry affect the shape, in particular the width, of the U L3-edge NEXAFS for U(vi) in octahedral coordination. The full-width-half-maximum (FWHM) of the L3-edge white line decreases with increasing distortion from Oh symmetry. In particular, the FWHM of the white line narrows whether the tetragonal distortion is to compression or to extension. The origin of this decrease in the FWHM is analyzed in terms of the electronic structure of the excited levels arising from the unoccupied U(6d)...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28324688/estimating-doses-from-aboriginal-bush-foods-post-remediation-of-a-uranium-mine
#11
Che Doering, Andreas Bollhöfer, Peter Medley
This paper presents a calculator to facilitate assessments of ingestion doses from Aboriginal bush foods. The calculator combines information on traditional diet and land use with radionuclide concentration ratios and ingestion dose coefficients to estimate doses. The calculator was applied to the planned remediation of Ranger uranium mine to derive a set of scaling factors between radionuclide activity concentrations in environmental media and ingestion dose from bush foods. The scaling factors can be used to estimate doses from bush foods once the post-remediation radiological conditions of the mine and surrounding environment are known...
March 18, 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/28324669/bacterial-endophytes-enhance-phytostabilization-in-soils-contaminated-with-uranium-and-lead
#12
Muhammad Tayyab Ahsan, Muhammad Najam-Ul-Haq, Muhammad Idrees, Inayat Ullah, Muhammad Afzal
The combined use of plants and bacteria is a promising approach for the remediation of polluted soil. In the current study, the potential of bacterial endophytes in partnership with Leptochloa fusca (L.) Kunth was evaluated for the remediation of uranium (U)- and lead (Pb)-contaminated soil. L. fusca was vegetated in contaminated soil and inoculated with three different endophytic bacterial strains, Pantoea stewartii ASI11, Enterobacter sp. HU38, and Microbacterium arborescens HU33, individually as well as in combination...
March 21, 2017: International Journal of Phytoremediation
https://www.readbyqxmd.com/read/28318317/characterization-kinetics-and-thermodynamics-of-biosynthesized-uranium-nanoparticles-unps
#13
Mervate Aly Abostate, Youssry Saleh, Hamed Mira, Maysa Amin, Maha Al Kazindar, Basma Mahmoud Ahmed
The present study was carried out to explore the potential of the isolated bacterial strains isolated from Gabal El Sela in Eastern Dessert, Egypt for biosynthesis of uraninite nanoparticles intracellularly. The most potent bacterial strains associated (intra) with uranium nanoparticles were characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR) and Energy Dispersive X-ray (EDX). Studying factors affecting biosynthesis of uranium nanoparticles indicated that the optimum conditions were 6000 ppm uranium concentrations at pH 7...
March 20, 2017: Artificial Cells, Nanomedicine, and Biotechnology
https://www.readbyqxmd.com/read/28317950/in-vivo-identification-of-potential-uranium-protein-targets-in-zebrafish-ovaries-after-chronic-waterborne-exposure
#14
Y Eb-Levadoux, S Frelon, O Simon, C Arnaudguilhem, R Lobinski, S Mounicou
Ecotoxicological studies have indicated the reprotoxicity of uranium (U) in zebrafish, but its molecular mechanisms remain unclear. Due to the non-covalent nature of U-protein complexes, canonical proteomics approaches are often not relevant as they usually use denaturating reagents or solvents. In this study, non-denaturating (ND) methods were used to obtain insight into the nature of U potential targets in ovaries of reproduced and non-reproduced zebrafish after 20 days of exposure to an environmentally relevant U concentration (20 μg L(-1))...
March 20, 2017: Metallomics: Integrated Biometal Science
https://www.readbyqxmd.com/read/28316246/uranium-tetrakis-aryloxide-derivatives-supported-by-tetraazacyclododecane-synthesis-of-air-stable-coordinatively-unsaturated-u-iv-and-u-v-complexes
#15
Julian Hümmer, Frank W Heinemann, Karsten Meyer
We present the synthesis, characterization, and one-electron oxidation of two uranium(IV) complexes, coordinated to the cyclen-anchored tetrakis(aryloxide) ligands tetrakis-hydroxybenzyl-1,4,7,10 tetraazacyclododecane, ((R,R)ArOH)4cyclen; R = (t)Bu, Me. The new uranium(IV) and (V) complexes exhibit an eight-coordinate, tetragonal ligand environment, effecting exceptional stability of the coordinatively unsaturated uranium compounds. Cyclic voltammetry studies reveal redox events ranging from tri- to hexavalent species, covering an electrochemical window of ∼4 V...
March 20, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28303615/rare-earth-elements-and-select-actinoids-in-the-canadian-house-dust-study
#16
Pat E Rasmussen, Christine Levesque, Marc Chénier, H David Gardner
Nationally representative baseline data are presented for rare earth elements (REE), plus thorium (Th) and uranium (U) in house dust sampled from 1025 urban homes, in units of concentrations (μg g(-1) ), loadings (μg m(-2) ) and loading rates (ng m(-2) day(-1) ). Spearman rank correlations indicate that, in addition to outdoor sources, consumer products and building materials can influence indoor dust concentrations of REE, Th and U. Correlations (p <0.01) with numbers of occupants, dogs and cats suggest soil track-in...
March 17, 2017: Indoor Air
https://www.readbyqxmd.com/read/28301832/recovery-of-uranium-vi-from-aqueous-solution-by-2-picolylamine-functionalized-poly-styrene-co-maleic-anhydride-resin
#17
Shudi Liu, Ying Yang, Tonghuan Liu, Wangsuo Wu
A 2-picolylamine functionalized poly(styrene-co-maleic anhydride) resin was synthesized and characterized by FT-IR, elemental analysis, SEM and XPS. To recover uranium from aqueous solution, the influence factors such as pH values, contact time, temperature and initial uranium concentration were optimized. Adsorption kinetics fitted well with the pseudo-second-order model, whereas adsorption isotherm matched well with the Langmuir isothermal adsorption model, with the maximum sorption capacity of 518.39mgg(-1) at pH 5...
July 1, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28300407/dynamic-succession-of-groundwater-sulfate-reducing-communities-during-prolonged-reduction-of-uranium-in-a-contaminated-aquifer
#18
Ping Zhang, Zhili He, Joy D Van Nostrand, Yujia Qin, Ye Deng, Liyou Wu, Qichao Tu, Jianjun Wang, Christopher W Schadt, Matthew W Fields, Terry C Hazen, Adam P Arkin, David A Stahl, Jizhong Zhou
To further understand the diversity and dynamics of SRB in response to substrate amendment, we sequenced genes coding for the dissimilatory sulfite reductase (dsrA) in groundwater samples collected after an emulsified vegetable oil (EVO) amendment, which sustained U(VI)-reducing conditions for one year in a fast-flowing aquifer. EVO amendment significantly altered the composition of groundwater SRB communities. Sequences having no closely related-described species dominated (80%) the indigenous SRB communities in nonamended wells...
March 16, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28290930/medical-effects-of-a-transuranic-dirty-bomb
#19
Asaf Durakovic
The modern military battlefields are characterized by the use of nonconventional weapons such as encountered in the conflicts of the Gulf War I and Gulf War II. Recent warfare in Iraq, Afghanistan, and the Balkans has introduced radioactive weapons to the modern war zone scenarios. This presents the military medicine with a new area of radioactive warfare with the potential large scale contamination of military and civilian targets with the variety of radioactive isotopes further enhanced by the clandestine use of radioactive materials in the terrorist radioactive warfare...
March 2017: Military Medicine
https://www.readbyqxmd.com/read/28286974/natural-radioactivity-levels-and-associated-health-hazards-from-the-terrestrial-ecosystem-in-rosetta-branch-of-the-river-nile-egypt
#20
W M Abdellah, H M Diab, S U El-Kameesy, E Salama, S El-Framawy
Twenty soil and 25 sediment samples were collected from the banks and bottom of the River Nile in the surroundings of biggest cities located close to it. Natural radioactivity concentrations of (226)Ra, (232)Th and (40)K have been evaluated for all samples by means of γ spectrometric analysis. The radioactivity levels of soil and sediment samples fall within the internationally recommended values. Nevertheless, high natural background radiation zones are detected in the Kafr El-Zayat region due to the presence of a fertilizer factory, and in the Rosetta region due to the presence of black sand deposits...
March 13, 2017: Isotopes in Environmental and Health Studies
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