Uranium level in drinking water is usually in the range of microgram-per-liter, but this value may be as much as 100 to 1000 times higher in some areas, which may raise question about the health consequences for human populations living in these areas. Our purpose was to improve knowledge of chemical effects of uranium following chronic ingestion. Experiments were performed on rats contaminated...

The soil-mushroom transfer of thorium and uranium was analyzed in two ecologically similar but geographically separated Spanish ecosystems by means of the transfer factor, TF. Uranium TF values were in the range 0.043-0.49, and thorium TF values in the range 0.030-0.62. These values were similar to those of (90)Sr, (239+240)Pu, and (241)Am found previously in the same ecosystems. Given the low ...

Over the past two years, research on drift prospecting in the District of Keewatin has been directed towards developing reconnaissance and detailed sampling techniques that can indicate uranium mineralization a s well a s base metal mineralization. Shilts and Klassen (1976) have presented some preliminary results of the uranium phase for Boothia Peninsula and central Keewatin. The purposes of t...

Tetravalent uranium is commonly assumed to form insoluble species, resulting in the immobilization of uranium under reducing conditions. Here we present the first report of mobile U(IV)-bearing colloids in the environment, bringing into question this common assumption. We investigate the mobility of uranium in a mining-impacted wetland in France harbouring uranium concentrations of up to 14,000...

Bioreactor leaching using enriched culture of Acidithiobacillus ferrooxidans and Leptosprillium ferrooxidans was investigated for the apatite rich Indian (Narwapahar) uranium ore. Bioreactor leaching of Narwapahar ore of <45 μm size at pH 2.0 and 10% (w/v) PD using 10% (v/v) inoculum of the bacterium at 35 °C (A. ferrooxidans) and 40 °C (L. ferrooxidans), solubilised 57% and 63% uranium in 5 da...

The main goal of this study is to investigate the capability of zeolites A and P synthesized from Iranian natural clinoptilolite for uranium uptak. The removal of uranium(VI) from aqueous solution via ion exchange by zeolites in a single component system with various contact times,  temperatures and initial concentrations of uranium(VI) was investigated. The experimental results we...

Uranium (VI) is considered to be one of the most widely dispersed and problematic environmental contaminants, due in large part to its high solubility and great mobility in natural aquatic systems. We previously reported that under anaerobic conditions, Shewanella oneidensis MR-1 grown in medium containing uranyl acetate rapidly accumulated long, extracellular, ultrafine U(VI) nanofibers compos...

The reactive oxygen species (ROS)-signaling pathway is very important in heavy metal toxicity. Induction of the antioxidative defense mechanism, comprising ROS-scavenging enzymes and metabolites, in plants after environmental uranium contamination has been insufficiently studied in the past. This study aimed to analyze oxidative stress related responses in Arabidopsis thaliana after uranium exp...

Environmental monitoring of actinides and evaluation of the contamination source (nuclear weapons tests, nuclear power plant and nuclear reprocessing plant accidents, etc.) requires precise and accurate isotopic analysis of actinides, especially uranium and plutonium. Double-focusing sector-field inductively coupled plasma mass spectrometry (ICP-SFMS) using a low-flow microconcentric nebulizer ...

The influence of organic-hexavalent-uranium [U(VI)] complexation on U(VI) reduction by a sulfate-reducing bacterium (Desulfovibrio desulfuricans) and an iron-reducing bacterium (Shewanella alga) was evaluated. Four aliphatic ligands (acetate, malonate, oxalate, and citrate) and an aromatic ligand (tiron [4,5-dihydroxy-1,3-benzene disulfonic acid]) were used to study complexed-uranium bioavailab...