Development of a methodology for dose assessment and estimate of amount of NORM residues disposable in a conventional landfill.

The final disposal of NORM wastes in conventional landfill generally determines problems of acceptance by the landfill operators, since their willingness to accept Naturally Occurring Radioactive Material (NORM) is often limited due to their concern about the radiological risks and reluctance of the local community to have at local landfills material that despite being cleared is still perceived as 'radioactive'. In order to raise awareness among landfill operators, and also among other stakeholders on the actual radiological risk of exempted or cleared NORM wastes, it is of interest to estimate the mass of annual wastes containing NORM that can be disposed of in a landfill for conventional waste complying with the annual dose criterion of 1 mSv. A methodology was developed considering a hypothetical homogeneous large landfill and assuming that NORM wastes are delivered with an initial activity concentration of 1 kBq kg.

Simultaneous measurement of labile U(VI) concentration and (U/U) activity ratio using a Monophos®-based Diffusive Gradients in thin-films sampler.

Background: In a context of environmental monitoring around installations related to the nuclear fuel cycle, the Diffusive Gradient in Thin-films (DGT) technique captures the integrated concentration of U isotopes in their native environment, yielding comprehensive data on U origin (anthropogenic vs natural), total concentration, and mobility. However, for common deployment times (4-5 days) in moderately basic waters, none of the commercially available binding gels is adapted to measure the total U concentration. So, the development of novel DGT binding gels is timely.

A methodology for the systematic identification of naturally occurring radioactive materials (NORM).

Naturally occurring radioactive materials (NORM) are present worldwide and under certain circumstances (e.g., human activities) may give radiation exposure to workers, local public or occasional visitors and non-human biota (NHB) of the surrounding ecosystems.

Uncoupling Aluminum Toxicity From Aluminum Signals in the STOP1 Pathway.

Aluminum (Al) is a major limiting factor for crop production on acidic soils, inhibiting root growth and plant development. At acidic pH (pH < 5.5), Al ions are the main form of Al present in the media.

Cesium transfer to millet and mustard as a function of Cs availability in soils.

Cs is one of the most persistent radioactive contaminants in soil after a nuclear accident. It can be taken up by plants and enter the human food chain generating a potential human health hazard. Although a large amount of literature has highlighted the role of the different processes involved in Cs uptake by plants, there is still no simple way to predict its transfer for a specific plant from a particular soil.

Chronic toxicity of uranium to three benthic organisms in laboratory spiked sediment.

Due to mining activities, concentration of uranium (U) in the environment nearby former and operating sites can be higher than in other areas. The derivation of quality criteria for U in freshwater ecosystems, rivers and lakes includes the consideration of contaminated sediments and the associated risk to the benthic life. Therefore, the derivation of a quality criteria for sediment has been viewed as a logical and necessary extension of the work already done to establish water quality criteria.

Discovery and characterization of UipA, a uranium- and iron-binding PepSY protein involved in uranium tolerance by soil bacteria.

Uranium is a naturally occurring radionuclide. Its redistribution, primarily due to human activities, can have adverse effects on human and non-human biota, which poses environmental concerns. The molecular mechanisms of uranium tolerance and the cellular response induced by uranium exposure in bacteria are not yet fully understood.

Dissolved iodide in marine waters determined with Diffusive Gradients in Thin-films technique.

For the first time, Diffusive Gradient in Thin-films (DGT) focuses on the inorganic iodine species iodate (IO) and iodide (I). A silver-doped Cl resin (AgdCl), which is known to selectively accumulate I, was used to make a binding gel. Laboratory investigations were designed to verify the suitability of the AgdCl-DGT method to measure the total I concentration in environmental waters.

Efficiency of dihydroxamic and trihydroxamic siderochelates to extract uranium and plutonium from contaminated soils.

Actinide-based mineral phases occurring in contaminated soils can be solubilized by organic chelators excreted by plants, such as citrate. Herein, the efficiency of citrate towards U and Pu extraction is compared to that of siderophores, whose primary function is the acquisition of iron(III) as an essential nutrient and growth factor for many soil microorganisms. To that end, we selected desferrioxamine B (DFB) as an emblematic bacterial trishydroxamic siderophore and a synthetic analog, abbreviated (L)H, of the tetradentate rhodotorulic acid (RA) produced by yeasts.

Evaluation of DGT and DGT-PROFS modeling approach to estimate desorption kinetics of Cs in soils.

The aim of this paper is to assess the suitability of DGT to extract kinetic rates of desorption of cesium (Cs) from soils. For this purpose, laboratory experiments with a natural soil spiked with Cs were carried out under three different contamination conditions, reflecting either an increase in Cs contamination level or an ageing of the contamination within the soil. The experimental results, i.

Use of fish otoliths as a temporal biomarker of field uranium exposure.

This study aimed to determine uranium (U) pollution over time using otoliths as a marker of fish U contamination. Experiments were performed in field contamination (~20 μg L: encaged fish: 15d, 50d and collected wild fish) and in laboratory exposure conditions (20 and 250 μg L, 20d). We reported the U seasonal concentrations in field waterborne exposed roach fish (Rutilus rutilus), in organs and otoliths.

Better understanding and applications of ammonium 12-molybdophosphate-based diffusive gradient in thin film techniques for measuring Cs in waters.

This study deals with further and systematic laboratory evaluation of the already known ammonium 12-molybdophosphate (AMP)-diffusive gradient in thin film (DGT) method, which is used for measuring total Cs concentration in environmental waters. This study confirms that the AMP-binding gel is not stable for pH > 6. In order to reveal a potential impact of AMP degradation on DGT application, time-series experiments were performed by deploying AMP-DGT samplers in Cs-doped moderately basic soft and hard water up to total AMP-binding gel degradation (60 and 175 h of deployment time, respectively).

Soil prokaryotic communities in Chernobyl waste disposal trench T22 are modulated by organic matter and radionuclide contamination.

After the Chernobyl nuclear power plant accident in 1986, contaminated soils, vegetation from the Red Forest and other radioactive debris were buried within trenches. In this area, trench T22 has long been a pilot site for the study of radionuclide migration in soil. Here, we used 454 pyrosequencing of 16S rRNA genes to obtain a comprehensive view of the bacterial and archaeal diversity in soils collected inside and in the vicinity of the trench T22 and to investigate the impact of radioactive waste disposal on prokaryotic communities.

Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns.

Actinides determination in urine samples is part of the analyses performed to monitor internal contamination in case of an accident or a terrorist attack involving nuclear matter. Mineralisation is the first step of any of these analyses. It aims at reducing the sample volume and at destroying all organic compounds present.

Use of combined microscopic and spectroscopic techniques to reveal interactions between uranium and Microbacterium sp. A9, a strain isolated from the Chernobyl exclusion zone.

Although uranium (U) is naturally found in the environment, soil remediation programs will become increasingly important in light of certain human activities. This work aimed to identify U(VI) detoxification mechanisms employed by a bacteria strain isolated from a Chernobyl soil sample, and to distinguish its active from passive mechanisms of interaction. The ability of the Microbacterium sp.

An invitation to contribute to a strategic research agenda in radioecology.

With intentions of integrating a portion of their respective research efforts into a trans-national programme that will enhance radioecology, eight European organisations recently formed the European Radioecology ALLIANCE (www.er-alliance.org).

Influence of uranium on bacterial communities: a comparison of natural uranium-rich soils with controls.

This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.

Radioecological risk assessment of low selenium concentrations through genetic fingerprints and metabolic profiling of soil bacterial communities.

In a context of environmental risk assessment of nuclear (79)Se radionuclide, the impact of low Se-selenite concentrations (0.008 and 8 mg kg(-1)) on bacterial communities of two soils, a silty clay loam and a sandy soil, was investigated over a 6-month incubation time. This Se-selenite was partially labelled with (75)Se.

Aqueous, solid and gaseous partitioning of selenium in an oxic sandy soil under different microbiological states.

The aim of this study was to investigate the role of microorganisms on the behaviour of selenium in natural soil maintained under strictly aerobic conditions. Six-day batch experiments were performed with soils constrained to different microbiological states, either by sterilisation or by adding organic substrates. Selenium was added to the soil as selenite.

Groups of adjacent contour segments for object detection.

We present a family of scale-invariant local shape features formed by chains of k connected, roughly straight contour segments (kAS), and their use for object class detection. kAS are able to cleanly encode pure fragments of an object boundary, without including nearby clutter. Moreover, they offer an attractive compromise between information content and repeatability, and encompass a wide variety of local shape structures.

Concomitant Zn-Cd and Pb retention in a carbonated fluvio-glacial deposit under both static and dynamic conditions.

The chemical and physical processes involved in the retention of 10(-2)M Zn, Pb and Cd in a calcareous medium were studied under saturated dynamic (column) and static (batch) conditions. Retention in columns decreased in order: Pb>>Cd approximately Zn. In the batch experiments, the same order was observed for a contact time of less than 40h and over, Pb>>Cd>Zn.