High Uranium Content Research Articles

Radon concentration potential in Bibala municipality water: Consequences for public consumption

The primary motivation for this work is the evaluation of the radon concentration in drinking water for human consumption in Bibala, a municipality in Angola, where granitic rocks are common, and contain a high concentration of uranium that can be mobilized in underground water. Radon is the largest contributor of radioactive pollution in underground water. Its concentration in water, represents a public health risk due to the fact that the gas can easily escape into the air, adding to the total indoor concentration of radon. On the other hand, ingestion of water with a high radon concentration represents an additional risk to the stomach. Measurements of radon concentration, in Bibala municipality's water, were performed by collecting 3 samples from each of the 27 water wells of diverse depth, with DURRIDGEs' RAD7 and the average radon concentration are identified by S1 to S27. Measured concentrations are in the range from 5.3 ± 0.6 to 42 ± 5 Bq L−1, with 67% of the recovered samples presenting values over 11 BqL−1, the USEPA recommended level and all samples present radon concentration below 100 Bq L−1, the WHO recommendation level.

Geological alteration of organic macromolecules by irradiation: Implication for organic matter occurrence on Mars

Abstract The harsh radiation environment on Mars is widely believed to destroy organic matter, but elucidating the systematic degradation pathway and its controlling factors has proved elusive. Here we show the alteration of macromolecular organic matter in the ∼500-m.y.-old uranium-rich Alum Shale Formation (northwestern Europe), which is suggested as a geological analogue on Earth of the Martian surface samples, in response to ⟨-particle irradiation. The composition and quantity of pyrolysates as well as the extractability of immature Alum Shale are governed by uranium content, and this has been confirmed independently using uranium-rich shales of younger geological age. During the course of irradiation, macromolecules undergo cross-linking, demethylation, and aromatization processes, which are active at different stages in the alteration of the organic matter. A comparison of the Martian surface samples with Kolm (carbonaceous nodules with very high uranium content intercalated in the Alum Shale) samples in terms of irradiation dosage and organic geochemical characteristics reveals that they have received similar levels of irradiation. A model of the radiation-induced alteration of organic matter has been developed, which opens a window for understanding the possible pristine nature and composition of the irradiated organic matter on Mars and offers arguments to qualitatively predict potential organic matter in the Martian paleo-lacustrine subsurface.

ВЛИЯНИЕ ГЕОЛОГИЧЕСКИХ ФАКТОРОВ НА РАСПРЕДЕЛЕНИЕ УРАНА И ТОРИЯ В СОЛЕВЫХ ОТЛОЖЕНИЯХ ПИТЬЕВЫХ ВОД (РЕСПУБЛИКА БАШКОРТОСТАН)

Актуальность исследования обусловлена необходимостью выявления источников поступления естественных радиоактивных элементов в питьевую воду,а также возможностью использования солевых отложений питьевых вод (накипи) в геохимических и экологических исследованиях. Наличие на территории Башкортостана различных геологических структур (горная область, предгорный прогиб, платформа), а также большое разнообразие горных пород различного возраста и состава (вулканогенные, интрузивные, осадочные, метаморфические) благоприятствует данным исследованиям и обуславливает большое разнообразие микроэлементного профиля местности. Цель:оценка содержания и пространственного распределения радиоактивных элементов в солевых отложениях питьевых вод (накипи) на территории Республики Башкортостан. Объекты. Проанализированы данные по содержанию U и Th в 467 пробах солевых отложений питьевых вод (накипи) из 267 населенных пунктов Республики Башкортостан. Пробы отобраны из различной посуды (эмалированные и электрические чайники, кастрюли, котлы, самовары), которая используется для кипячения воды из централизованных и индивидуальных (скважины, колодцы, ручьи) источников водоснабжения. Методы. Для анализа содержания Uи Thиспользовался метод инструментального нейтронно-активационного анализана базе исследовательского ядерного реактора ИРТ-Т ТПУ. Обработка данных проводилась с использованием программных пакетов Statistica 8.0 и MicrosoftExcel 2013. Построение карт пространственного распределения естественных радиоактивных элементов в солевых отложениях питьевых вод проведено с помощью программы ArcGIS 10.2 в модуле GeostatisticalAnalyst методом обратных расстояний. Результаты. Полученные данные позволяют говорить о неравномерном распределении естественных радиоактивных элементов (U, Th) в солевых отложениях на территории Республики Башкортостан. Региональный фон концентрацииU и Th отличается пониженными значениями. Вариации их содержания определяются воздействием как природных, так и антропогенных факторов. Закономерности распределения U в пробах накипи хорошо согласуются с особенностями геологического строения территории. В пределах платформенной части распределение Uявляется более равномерным по площади, чем в горной части республики, что отражает сравнительную однородность геологических и тектонических условий. По результатам картирования выделено четыре зоны повышенного содержания Uв образцах солевых отложений: зауральская, уральская, западная и южная.В пространственном распределении Th не выявлено четкой корреляционной связи с особенностями геологического строения и металлогении территории. Выделены три зоны: северная, центральная и юго-восточная. Отмечены отрицательные аномалии содержания Th, территориально совпадающие с крупными горнодобывающими центрами.Показатель Th/U отношения характеризуется низким значением для всей территории Башкортостана – 0,002. При этом положительные аномалии данного показателя зафиксированы в северной и юго-восточной частях республики, где они обусловлены, преимущественно, геологической составляющей.

Radiogenic helium concentration and isotope variations in crustal gas pools from Sichuan Basin, China

Helium is an exhaustible natural resource and the main commercial helium was separated from helium-rich natural gas. The helium in the sedimentary basin is mainly the radiogenic origin of crustal rocks with high level of uranium and thorium. Data from 242 natural gas samples were used to investigate the distribution and formation mechanism of helium-rich gases in the Sichuan Basin of China. All gas samples show remarkably low 3He/4He ratios with ranging from 0.002 to 0.05 Ra, which represent typical crustal helium. The Weiyuan gas pool in the southern Sichuan Basin possesses high levels of helium (1500–18770 ppm, average 2785.7 ppm) in Precambrian and Cambrian strata. A positive relationship were observed in the helium and nitrogen contents increased with reservoir layer age for all Weiyuan gas samples. Presinian granite was considered as the main helium source for the Weiyuan gas pool. Gaoshiti–Moxi and Weiyuan gas pools belonged to the same ancient gas pool before the Late Cretaceous, but the helium abundance of Gaoshiti–Moxi gas pool is relatively low (200–891 ppm). The change of pressure and fracture system caused by the uplift of Weiyuan structure in the Himalayan orogenesis led to the helium accumulation and enrichment of Weiyuan gas pool. The shale of the Silurian Longmaxi Formation has high contents of uranium and thorium and generated a large amount of helium while forming large quantities of hydrocarbon gases. Generally, the helium abundance of shale gases and conventional gases generated from the Longmaxi Formation ranges from 63 to 1500 ppm and some of the gas pool are sufficient for commercial helium resource exploitation. Therefore, the relative quantities of helium and hydrocarbon gases are act as a key factor influencing the formation of helium-rich natural gas reservoirs.

Development of phosphate glass and multi-phase titanate ceramic compositions for thermal treatment of irradiated nuclear fuel residues

The highly heterogeneous nature of UK legacy damaged and degraded spent nuclear fuels and so called, ‘orphan fuels’, prohibits the use of standard conditioning methods. An inventory of UK residual fuels yielded an account for three main fuel types: Magnox, AGR (advanced gas-cooled reactor) and MOx (mixed oxides). A series of glass and ceramic type host systems have been investigated for potential conditioning of these high uranium content spent fuel materials. Electron microscopy and powder X-ray diffraction techniques were used to characterise the prototypical wasteforms. Two sets of low-melt temperature phosphate glass compositions were trialled with additions of CeO2 to simulate the fluorite structure and large ionic radius of U in oxide fuels. Evolution of monazite-type phases at simulant oxide fuel loadings above 15 wt.% highlighted a potential development into a glass-ceramic hybrid assemblage. Investigation into the use of an alkoxide nitrate synthesis route for SYNROC-F type ceramic precursors has allowed for the demonstration of a sintered host pyrochlore phase containing up to ∼40 wt.% fuel simulant CeO2. Gas evolution has led to increased porosity at higher temperatures and longer sintering times, this may be mitigated by higher pre-calcination temperatures.

Evaluation of Uranium in Organs of Residents from an Uranium-Rich Region using Teeth as Bioindicators

The Uranium extraction and processing plant of INB (Brazilian Nuclear Industries) is in Caetité, a city located in a region hosting the largest Uranium reserve of the country. The degree of Uranium contamination in the Caetité population was investigated before using teeth as bioindicator, where a quite high Uranium concentration was measured in this region, about 160 times higher than the world-wide average.

Quality of Drinking Water in the Balkhash District of Kazakhstan’s Almaty Region

The thinly populated Balkhash District of Kazakhstan’s Almaty Region lies in the lower reaches of the Ili-Balkhash basin, which is shared by China and Kazakhstan. The district is arid and heavily dependent on inflows of surface water, which are threatened by the effects of upstream population growth, economic development, and climate change. The quality of drinking water from centralized water systems and tube wells in nine villages of the district was analyzed, and the organoleptic properties of water from these sources was also assessed by an expert and via surveys of local residents. Although most samples met governmental standards for the absence of chemical impurities, high concentrations of mineralization, chlorides, boron, iron, and/or uranium were present in some well water samples. Levels of these pollutants were as much as 4-fold higher than governmental maxima and as much as 16-fold higher than concentrations reported previously in surface water. All centralized water samples met standards for absence of microbial contamination, but total microbial counts in some well water samples exceeded standards. Organoleptic standards were met by all the water from five villages, but centralized water from one village and well water from four villages failed to meet standards based on expert judgment. Residents were, for the most part, more satisfied with centralized rather than well water, but there was no obvious relationship between the failure of water to meet standards and the locations or populations of the settlements. This is the first comprehensive assessment of groundwater used for drinking in the lower Ili-Balkhash basin, and although it relies on a limited number of samples, it nevertheless provides evidence of potentially serious groundwater contamination in the Balkhash District. It is thus imperative that additional and more detailed studies be undertaken.

Resistant fungi isolated from contaminated uranium mine in Brazil shows a high capacity to uptake uranium from water

The Osamu Utsumi uranium mine occupies a 20 km2 area in the city of Caldas, which is located in the state of Minas Gerais, Brazil. Since mining activities ended at Osamu Utsumi 24 years ago, the surrounding area has become contaminated by acid effluents containing high concentrations of uranium. Thus, the aim of this study was to assess the uranium bioremediation capacity of 57 fungi isolated from the mine area. In tolerance tests, 38% (22) of the fungal isolates were considered tolerant to uranium, including 10 Penicillium species. At a uranium concentration of 2000 mg L−1 48 fungi did not exhibit mycelial growth index inhibition. Minimal inhibitory concentration (MIC) analysis showed growth of 25 fungi above a uranium concentration of 8000 mg L−1. At high uranium concentrations, some fungi (i.e., Talaromyces amestolkiae and Penicillium citrinum) showed morphological changes and pigment (melanin) production. Among the fungal isolates, those considered to be more tolerant to uranium were isolated from soil and sediment samples containing higher concentrations of heavy metal. When comparing the results of resistance/tolerance tests with those for uranium biosorption capacity, we concluded that the fungi isolated from the Osamu Utsumi mine with the best potential for uranium bioremediation were Gongronella butleri, Penicillium piscarium, Penicillium citrinum, Penicillium ludwigii, and Talaromyces amestolkiae. Biosorption tests with live fungal biomass showed that 11 species had a high potential for uranium uptake from contaminated water.

Geochemical characteristics and uranium mineralization exploration potential of late Miocene molasse sediments of NW Himalayan foreland basin Pakistan

This study has defined the provenance, tectonic settings, paleo-weathering, sediment-recycling, and sandstone-type uranium mineralization potential of late Miocene mid-Siwalik Dhok Pathan Formation from Surghar-Shingar Range of NW-Himalayan foreland Fold-and-Thrust-belt. Twenty-six sandstone samples were analyzed on XRF and ICP-MS to determine concentrations of different geochemical species. These Himalayan molasse sediments are moderately rich in quartz. The other framework gains include igno-metamorphic and sedimentary lithic fragments (second in abundance after quartz), feldspars, and dominance of ferroan phlogopite (biotite) over white mica. Garnet, epidot, amphibole, magnetite, tourmaline, rutile, zircon, monazite, and uranothorite are present as common accessory minerals. These sandstones are generally classified as lithic arenite, greywacke, and arkose on the basis of geochemistry. These molasse sediments have recorded the signatures of first-cycle detritus mainly contributed by felsic-igneous rocks in collision-arc tectonic settings. Chemical index of weathering and alteration (CIW and CIA) revealed slight/low weathering of source areas. The REE patterns and Eu/Eu* values are also supporting felsic-igneous provenance for the studied samples. The median high concentrations (ppm) of vanadium (V 79.57), thorium (Th 10.08) and uranium (U 33.05) in sandstone, positive correlation of U with Al2O3 (r = 0.22), deposition in strong anoxic environments are the characteristic features of uranium enrichment/accumulation processes in sandstone-type environments thus signifying good potential for uranium exploration.

Genomic and functional insights into the adaptation and survival of Chryseobacterium sp. strain PMSZPI in uranium enriched environment.

Metal enriched areas represent important and dynamic microbiological ecosystems. In this study, the draft genome of a uranium (U) tolerant bacterium, Chryseobacterium sp. strain PMSZPI, isolated from the subsurface soil of Domiasiat uranium ore deposit in Northeast India, was analyzed. The strain revealed a genome size of 3.8Mb comprising of 3346 predicted protein-coding genes. The analysis indicated high abundance of genes associated with metal resistance and efflux, transporters, phosphatases, antibiotic resistance, polysaccharide synthesis, motility, protein secretion systems, oxidoreductases and DNA repair. Comparative genomics with other closely related Chryseobacterium strains led to the identification of unique inventory of genes which were of adaptive significance in PMSZPI. Consistent with the genome analysis, PMSZPI showed superior tolerance to uranium and other heavy metals. The metal exposed cells exhibited transcriptional induction of metal translocating PIB ATPases suggestive of their involvement in metal resistance. Efficient U binding (~90% of 100μM U) and U bioprecipitation (~93-94% of 1mM U at pH 5, 7 and 9) could be attributed as uranium tolerance strategies in PMSZPI. The strain demonstrated resistance to a large number of antibiotics which was in agreement with in silico prediction. Reduced gliding motility in the presence of cadmium and uranium, enhanced biofilm formation on uranium exposure and tolerance to 1.5kGy of 60Co gamma radiation were perceived as adaptive responses in PMSZPI. Overall, the positive correlation observed between uranium/metal tolerance abilities predicted using genome analysis and the functional characterization reinforced the multifaceted adaptation strategies employed by PMSZPI for its survival in the soil of uranium ore deposit comprising of high concentrations of uranium and other heavy metals.

Association between Uranium Exposure and Thyroid Health: A National Health and Nutrition Examination Survey Analysis and Ecological Study.

Besides specific, incidental radiation exposure, which has been associated with increased thyroid cancer risk, the effects of exposure to background radiation from uranium, a naturally occurring, radioactive, and ubiquitous element, on the thyroid gland has not been widely studied. We therefore investigated the association between uranium exposure and thyroid health in the US. Using the National Health and Nutrition Examination Survey (NHANES), we assessed the association between urinary uranium levels and thyroid-related antibodies, including thyroglobulin antibodies (TgAb) and anti-thyroid peroxidase (anti-TPO), in the general population. Secondly, we performed an ecological study of age-adjusted thyroid cancer incidence rates per state and sources of uranium exposure. We included 3125 eligible participants from the NHANES and found a significant association between increased TgAb and increased urinary uranium levels when analyzed as quartiles (p = 0.0105), while no association was found with anti-TPO. In addition, although no significant correlation was found in the ecological study, certain states had high age-adjusted thyroid cancer incidence rates and a high number of uranium activity locations and high uranium concentrations in water. The present study suggests that uranium exposure may affect thyroid health, which warrants increased sampling of soil and water in high-risk states.

Autunite-Group Minerals and Their Paragenesis from the Sheared Granite of Gabal El Sela, South Eastern Desert, Egypt

G. El Sela is located in the Southern Eastern Desert of Egypt cropping as two parts, occupied by monzogranites that were categorized as biotite granite, muscovite granite and two mica granites. The northern part is more significant according its high concentrations of uranium that controlled by complicated structure regime; faulting, infrastructures and shearing are the most common structural criteria of this part. The Egyptian Nuclear Materials Authority (NMA) mined this part to produce the uranium ore. The previous mineralogical studies indicated that this granite was dominated by primary uranium minerals (pitchblende and coffinite) and secondary minerals belong to the autunite group (autunite, metautunite, phurcalite) in addition to uranophane. In the present work, petrographic and mineralogical studies are applied for the granites using the polarized and stereo microscopes and followed by electron microscope and XRD. The result of the microscopic examinations revealed the tectonic regime controlling the radioactivity and recognized the sodic autunite (meta-natroautunite) beside the pre-mentioned autunite group minerals completing the paragenetic sequrnce of these minerals. In this study, it is concluded that the sheared biotite granite is monzogranite originated during the episode of the continental plate collision (syncollision). The study finished to presence of two main types of the alteration corresponding to the two high levels of radioactivity (moderate and anomalous). The first is the thermal alteration (saussiritization, sericitization, kaolinization, silicification and hematization) and the second is the chemical transformation (oxidation, dehydration, ion substitutions and confusion) responsible for formation of the secondary uranium minerals. The temperature needed for the thermal alteration is sourced by the hydrothermal solutions, while the temperature needed for the uranium minerals transformation may be generated during the episode of the continental plate collision (syncollision). Paragenesis of these minerals indicates that they represent a series of uranyl phosphate minerals (autunite group) with paragenetic sequence starting by autunite (calcic uranyl phosphate) and ends by meta-natroautunite (sodic uranyl phosphate). An advanced process of dehydration accompanies the process of mineral transformation from autunite to meta-natroautunite leading to formation of the anhydrous uranyl mineral (phurcalite) formed by oxidation and dehydration of autunite. Meta-autunite is recorded as a transitional mineral composed of sodic-calcic uranyl phosphate. Uranophane is created by thermal confusion of autunite with the silica.

Measurement of uranium concentrations in soil samples of Al-Diwaniyah governorate, Iraq by using CR-39 track detector

The present work is concerned with the measurements of uranium concentrations in forty-nine surface soils samples from selected locations (some of them were measured for the first time as far as authors know) in Al-Diwaniyah governorate by using uranium fission fragment U-235 (n-f), obtained by the bombardment of U-235 with thermal neutrons. The results have shown that the highest uranium concentration in surface soils samples in the selected regions in Al-Diwaniyah governorate was found in (Al-sdeer) region, which was equal to (8.86±0.89 ppm), while the lowest uranium concentration was found in (Al-shamr 2) region which was equal to (2.50±0.92 ppm) The present results have show that the uranium concentrations in the studied surface soils samples were less than the allowed value (11.7 ppm) recommended by UNSCEAR, 1993.

Radiometric and environmental impacts of mill tailings at experimental plant processing unit, Allouga, Egypt

Uranium mining and ore processing are known to be harmful to the environment and human health if the waste generated is not managed properly. The aim of the present study is to determine the radiological indices in the mill tailings and review the possible attempts to utilize and minimize its hazardous effect. The activity concentrations of natural radionuclides, 238U, 232Th, 226Ra, and 40K have been measured by gamma spectrometry using HP-Ge detector. The average activity concentrations of 238U, 232Th, 226Ra, and 40K in the tailings wastes were 2071.8, 59.92, 6921.262, and 445. 57 Bq/kg respectively which are higher than the international average limit. The ranges of hazard indices such as Radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), γ-radiation hazard index Iγ, Dose rate (nGy/h) and annual effective dose equivalent (AED), were estimated. Uraniumm isotopic ratios in the ore –material and mill tailing samples indicate migration out of radionuclides to the surrounding environment causing contamination and many dangerous diseases. Fairly, all investigated tailing waste samples do not satisfy the universal standards, the studied wastes relatively still have high uranium contents and need reprocessing.

Association of uranium with macerals in marine black shales: Insights from the Upper Devonian New Albany Shale, Illinois Basin

Marine organic-rich shales generally have high uranium content associated with sedimentary organic matter. However, organic matter in black shales is not homogeneous, but instead a mixture of different macerals. The uranium content and organic petrographic composition of 27 New Albany Shale samples indicate differential contributions of macerals to the uranium content in the Upper Devonian New Albany Shale of the Illinois Basin. Specifically, uranium is mainly associated with amorphous organic matter (microbially degraded phytoplankton, zooplankton, and bacterial biomass), where an average uranium content of approximately 550 ppm has been estimated. The amorphous organic matter's lack of structure, as well as admixed with mineral grains (<7.8 μm) suggest that it originated via microbial degradation in surficial sediments. Uranium may have been incorporated into amorphous organic matter during phytoplankton degradation and amorphous kerogen formation early in diagenesis. Pore-water redox conditions and pH control the reduction of uranium (VI) and its incorporation into amorphous organic matter. Alginite derived from Tasmanites algae (average uranium content <10 ppm) contributes minimally to uranium content. Terrestrial organic matter in the New Albany Shale contains on average ~ 20 ppm uranium, and because it accounts for <10% of total organic matter in the New Albany Shale, its contribution is equally negligible.

A method to determine uranium compounds in drinking water

In this paper we have studied the possibility of determining the forms of uranium ions and minerals dissolved in water by using the Pourbaix diagram. Uranium in water with low uranium content exists in the form of uraninite or uranium dioxide UO2+ and with higher uranium content in the form of ions UO2(CO3). By selecting carbonate minerals and calculating the saturation index, it is shown that uranium in the water of Eastern region of Mongolia dissolved in the forms of minerals such as quartzite CaMgUO2(CO3)3(H2O)12, andersonite (Na2CaUO2(CO3)3(H2O)6), bayleyite (Mg2UO2(CO3)3(H2O)18), liebigite (Ca2UO2(CO3)3(H2O)10).

Geology, geochemistry, and radioactivity of El Maghrabiya young granites, Central Eastern Desert, Egypt

The young granites of El Maghrabiya area located at the Central Eastern Desert, the southwestern part, are intensively altered along faults, fractures, and shear zones. Microscopically, the studied granites are classified as syenogranite and the altered portion exhibits features of ferrugination and episyenitization. This granite belongs to the high silica and low calcium, iron, and magnesium granites reflecting their origin from highly fractionated potassium-rich crustal material. El Maghrabiya syenogranites are generally uraniferous especially the altered portion that is characterized by high radioactivity. The hydrothermal activity is responsible for the formation of the anomalous zone characterized by extensive episyenitization and ferrugination processes. The ferruginated syenogranite has higher concentrations of uranium and thorium than the other altered granites (episyenitized). The present study revealed that zircon, fluorite, fluorapatite, and iron oxides are the most predominant U-bearing minerals in addition to uranophane that recorded in the ferruginated variety. The studied syenogranites characterized by two thorium ranges where the fresh granite exhibits the low range (22–45 ppm) and the altered granite characterized by the higher range (68–185 ppm) indicating that there are two pulses of the magma generating El Maghrabiya young granites. Uranium and thorium of the first generation are mostly attributed to the accessory minerals and related to the magmatic processes while the second generation is characterized by low Th/U ratio and high uranium content that is enriched by the hydrothermal solutions.

Bioaccumulation and Dispersion of Uranium by Freshwater Organisms.

Uranium is the heaviest naturally occurring element on Earth. Uranium mining may result in ground and surface water contamination with potential bioaccumulation and dispersion by aquatic invertebrates with aerial stages. We investigated the effects of uranium contamination at community level in terms of abundance, richness, the composition of invertebrate communities, and functional traits. We also investigated uranium mobility across aquatic food webs and its transfer to land via the emergence of aquatic insects. We sampled water, sediment, biofilm, macrophytes, aquatic invertebrates, adult insects, and spiders in the riparian zone across sites with a gradient of uranium concentrations in stream water (from 2.1 to 4.7µgL-1) and sediments (from 10.4 to 41.8µgg-1). Macroinvertebrate assemblages differed between sites with a higher diversity and predominance of Nemouridae and Baetidae at the reference site and low diversity and predominance of Chironomidae in sites with the highest uranium concentration. Uranium concentrations in producers and consumers increased linearly with uranium concentration in stream water and sediment (p < 0.05). The highest accumulation was found in litter (83.76 ± 5.42µgg-1) and macrophytes (47.58 ± 6.93µgg-1) in the most contaminated site. Uranium was highest in scrapers (14.30 ± 0.98µgg-1), followed by shredders (12.96 ± 0.81µgg-1) and engulfer predators (7.01 ± 1.3µgg-1). Uranium in adults of aquatic insects in the riparian zone in all sites ranged from 0.25 to 2.90µgg-1, whereas in spiders it ranged from 0.96 to 1.73µgg-1, with no differences between sites (p > 0.05). There was a negative relationship between δ15N and uranium, suggesting there is no biomagnification along food webs. We concluded that uranium is accumulated by producers and consumers but not biomagnified nor dispersed to land with the emergence of aquatic insects.

Study of Uranium in Drinking Water around the Sohna Fault Line in Haryana

ABSTRACT Quality of drinking water is associated directly with the health of mass population. Therefore, study on radiation level in groundwater has been taken up around the Sohna fault line, Haryana state, India. Uranium concentration has been measured in drinking water samples collected from sources such as hand pump, tube well from different depths around the Sohna fault line, using LED Fluorimetry Technique. Uranium concentration in study area varies from 0.10 μg/L to 223.16 μg/L with an average value of 22.09 μg/L. The average value of uranium concentration is within the safe limit recommended by World Health Organization (WHO, 2011) and Atomic Energy Regulatory Board. The annual effective dose has also been measured in all the water samples and is found to be below the prescribed dose limit of 100 μSvy–1 recommended by WHO (2011). Risk assessment of uranium in water is also calculated using life time cancer risk, life time average daily dose and hazard quotient. The high uranium concentration observed in certain areas is due to interaction of ground water with the soil formation of this region and the local sub-surface geology of the region.

Geophysical interpretation of the geology of the Stanthorpe region using aeromagnetic, gravity and radiometric data

This study provides an in-depth geophysical interpretation of the geology of the Stanthorpe region with a particular focus on hydrothermal alteration. The radiometric ternary map outlines the main lithological divisions in the region, which together with Th and Th/K ratio maps distinguish various granitic suites. Magnetic signatures delineate a non-magnetic zone within the low to moderately magnetic Stanthorpe Granite. The non-magnetic section, a north–northwest trending belt with a high density of faults and dykes is interpreted as a hydrothermal alteration zone that is narrower in the north, widens southwards, and is much more extensive at depth than is suggested by the surface alteration pattern. Modelling of gravity data reveals a massive low-density granitic intrusion extending to a depth of 10–15 km. The low-gravity section with modelled rock densities between 2450 and 2670 kg/m3 coincides with the low magnetic susceptibility zone in the magnetic model. High K, low Th and low Th/K also characterise the sections of the Stanthorpe Granite that have both low gravity and magnetic responses. Also conspicuous in the geophysical signatures within the non-magnetic zone is an ovoid feature of low magnetic response, high uranium content with moderate density, interpreted as a granitic pluton. Thus, decrease in magnetisation, changes in K concentration and corresponding low gravity with an associated high density of faults, fractures and dykes in the Stanthorpe region are the main features of the quartz–sericite–chlorite–muscovite hydrothermal alteration.