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International Journal of Molecular... Apr 2022This review summarizes the recent developments regarding the use of uranium as nuclear fuel, including recycling and health aspects, elucidated from a chemical point of... (Review)
Review
This review summarizes the recent developments regarding the use of uranium as nuclear fuel, including recycling and health aspects, elucidated from a chemical point of view, i.e., emphasizing the rich uranium coordination chemistry, which has also raised interest in using uranium compounds in synthesis and catalysis. A number of novel uranium coordination features are addressed, such the emerging number of U(II) complexes and uranium nitride complexes as a promising class of materials for more efficient and safer nuclear fuels. The current discussion about uranium triple bonds is addressed by quantum chemical investigations using local vibrational mode force constants as quantitative bond strength descriptors based on vibrational spectroscopy. The local mode analysis of selected uranium nitrides, N≡U≡N, U≡N, N≡U=NH and N≡U=O, could confirm and quantify, for the first time, that these molecules exhibit a UN triple bond as hypothesized in the literature. We hope that this review will inspire the community interested in uranium chemistry and will serve as an incubator for fruitful collaborations between theory and experimentation in exploring the wealth of uranium chemistry.
Topics: Catalysis; Spectrum Analysis; Uranium; Vibration
PubMed: 35563047
DOI: 10.3390/ijms23094655 -
Toxicology and Applied Pharmacology Nov 2022Uranium is a naturally occurring element found in the environment as a mixture of isotopes with differing radioactive properties. Enrichment of mined material results in... (Review)
Review
Uranium is a naturally occurring element found in the environment as a mixture of isotopes with differing radioactive properties. Enrichment of mined material results in depleted uranium waste with substantially reduced radioactivity but retains the capacity for chemical toxicity. Uranium mine and milling waste are dispersed by wind and rain leading to environmental exposures through soil, air, and water contamination. Uranium exposure is associated with numerous adverse health outcomes in humans, yet there is limited understanding of the effects of depleted uranium on the immune system. The purpose of this review is to summarize findings on uranium immunotoxicity obtained from cell, rodent and human population studies. We also highlight how each model contributes to an understanding of mechanisms that lead to immunotoxicity and limitations inherent within each system. Information from population, animal, and laboratory studies will be needed to significantly expand our knowledge of the contributions of depleted uranium to immune dysregulation, which may then inform prevention or intervention measures for exposed communities.
Topics: Animals; Environmental Exposure; Humans; Mining; Soil; Uranium; Water
PubMed: 36152676
DOI: 10.1016/j.taap.2022.116252 -
Environmental Health Perspectives Mar 2021Uranium contamination of drinking-water sources on American Indian (AI) reservations in the United States is a largely ignored and underfunded public health crisis. With... (Review)
Review
BACKGROUND
Uranium contamination of drinking-water sources on American Indian (AI) reservations in the United States is a largely ignored and underfunded public health crisis. With an estimated 40% of the headwaters in the western U.S. watershed, home to many AI reservation communities, being contaminated with untreated mine waste, the potential health effects have largely been unexplored. With AI populations already facing continued and progressive economic and social marginalization, higher prevalence of chronic disease, and systemic discrimination, associations between various toxicant exposures, including uranium, and various chronic conditions, need further examination.
OBJECTIVES
Uranium's health effects, in addition to considerations for uranium drinking-water testing, reporting, and mitigation in reference to AI communities through the lens of water quality, is reviewed.
DISCUSSION
A series of environmental health policy recommendations are described with the intent to proactively improve responsiveness to the water quality crisis in AI reservation communities in the United States specific to uranium. There is a serious and immediate need for better coordination of uranium-related drinking-water testing and reporting on reservations in the United States that will better support and guide best practices for uranium mitigation efforts. https://doi.org/10.1289/EHP7537.
Topics: Environmental Health; Hazardous Substances; Humans; Indians, North American; Policy; United States; Uranium; American Indian or Alaska Native
PubMed: 33769848
DOI: 10.1289/EHP7537 -
Environmental Science and Pollution... Nov 2022Different activities related to uranium mining and nuclear industry may have a negative impact on the environment. Bioremediation of nuclear pollutants using...
Different activities related to uranium mining and nuclear industry may have a negative impact on the environment. Bioremediation of nuclear pollutants using microorganisms is an effective, safe, and economic method. The present study compared the uranium biosorption efficiency of two immobilized algae: Nostoc sp. (cyanophyte) and Scenedesmus sp. (chlorophyte). Effects of metal concentration, contact time, pH, and biosorbent dosage were also studied. The maximum biosorption capacity (60%) by Nostoc sp. was obtained at 300 mg/l uranium solution, 60 min, pH 4.5, and 4.2 g/l algal dosage, whereas Scenedesmus sp. maximally absorbed uranium (65 %) at 150 mg/l uranium solution, 40 min, pH 4.5, and 5.6 g/l of algal dosage. The interaction of metal ions as NaSO, FeCl, CuCl, NiCl, CoCl, CdCl, and AlCl did not support the uranium biosorption by algae. The obtained data was adapted to the linearized form of the Langmuir isotherm model. The experimental q values were 130 and 75 mg/g for Nostoc sp. and Scenedesmus sp., respectively. Moreover, the pseudo-second-order kinetic model was more applicable, as the calculated parameters were close to the experimental data. The biosorbents were also characterized by Fourier-transform infrared spectroscopy (ATR-FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM) analyses. The results suggest the applicability of algae, in their immobilized form, for recovery and biosorption of uranium from aqueous solution.
Topics: Uranium; Scenedesmus; Adsorption; Nostoc; Kinetics; Water Pollutants, Chemical; Ions; Spectroscopy, Fourier Transform Infrared; Hydrogen-Ion Concentration; Thermodynamics
PubMed: 35771321
DOI: 10.1007/s11356-022-21641-9 -
Ecotoxicology and Environmental Safety Nov 2022Uranium is a radioactive heavy metal and a significant public health concern; however, its associated underlying toxicological mechanisms remain largely unknown. In this...
Uranium is a radioactive heavy metal and a significant public health concern; however, its associated underlying toxicological mechanisms remain largely unknown. In this work, the uptake and efflux processes of uranium in CHO-k1 cells were studied and the cytotoxicity effects were explored. It was found that both the uptake and efflux processes took place rapidly and half of the internalized uranium was expelled within 8 h. The uranium exposure caused a decrease of cell viability and adhesion ability in a dose-dependent manner and blocked the cell cycle at the G1 stage. In addition, gene expression analysis revealed relative changes in the transcription of metabolism related genes. Further studies revealed that the cytotoxicity of uranium could be alleviated by exposing cells to a lower temperature or by the addition of amantadine-HCl, an endocytosis inhibitor. Interestingly, after uranium exposure, needle-like precipitates were observed in both intracellular and extracellular regions. These findings collectively suggest that the cellular transport of uranium is a rapid process that disturbs cell metabolism and induces cytotoxicity, and this impact could be reduced by slowing down endocytic processes.
Topics: Cricetinae; Animals; Uranium; Cricetulus; CHO Cells; Cell Survival; Endocytosis
PubMed: 36228352
DOI: 10.1016/j.ecoenv.2022.114166 -
Reviews on Environmental Health Jun 2022A scoping review was performed to answer: what environmental health concerns have been associated with adverse health outcomes in the Navajo Nation? The review focused... (Review)
Review
A scoping review was performed to answer: what environmental health concerns have been associated with adverse health outcomes in the Navajo Nation? The review focused on occupational and ambient environmental exposures associated with human industrial activities. The search strategy was implemented in PubMed, and two investigators screened the retrieved literature. Thirteen studies were included for review. Data were extracted using the matrix method. Six studies described associations between work in uranium mining and cancer. Six studies focused on environmental exposures to uranium mine waste and other metals, with outcomes that included biological markers, kidney disease, diabetes and hypertension, and adverse birth outcomes. One study explored occupational exposure to Sin Nombre Virus and infection. Most research has focused on the health effects of uranium, where occupational exposures occurred among miners and environmental exposures are a legacy of uranium mining and milling. Gaps exist with respect to health outcomes associated with current occupations and the psychosocial impact of environmental hazards. Other environmental exposures and hazards are known to exist on the Navajo Nation, which may warrant epidemiologic research.
Topics: Environmental Exposure; Humans; Mining; Occupational Diseases; Occupational Exposure; Occupational Health; Uranium
PubMed: 34968017
DOI: 10.1515/reveh-2021-0118 -
Archives of Toxicology Mar 2022
Topics: History, 20th Century; History, 21st Century; Humans; Mining; Periodicals as Topic; Toxicology; Uranium
PubMed: 35118510
DOI: 10.1007/s00204-022-03223-3 -
Journal of Environmental Management Jan 2022Mining of uranium for defense-related purposes has left a substantial legacy of pollution that threatens human and environmental health. Contaminated waters in the arid...
Mining of uranium for defense-related purposes has left a substantial legacy of pollution that threatens human and environmental health. Contaminated waters in the arid southwest are of particular concern, as water resource demand and water scarcity issues become more pronounced. The development of remediation strategies to treat uranium impacted waters will become increasingly vital to meet future water needs. Ion flotation is one technology with the potential to address legacy uranium contamination. The green biosurfactant rhamnolipid has been shown to bind uranium and act as an effective collector in ion flotation. In this study, uranium contaminated groundwater (∼440 μg L U) from the Monument Valley processing site in northeast Arizona was used as a model solution to test the uranium removal efficacy of ion flotation with biosynthetic (bio-mRL) and three synthetic monorhamnolipids with varying hydrophobic chain lengths: Rha-C10-C10, Rha-C12-C12, and Rha-C14-C14. At the groundwater's native pH 8, and at an adjusted pH 7, no uranium was removed from solution by any collector. However, at pH 6.5 bio-mRL and Rha-C10-C10 removed 239.2 μg L and 242.4 μg L of uranium, respectively. By further decreasing the pH to 5.5, bio-mRL was able to reduce the uranium concentration to near or below the Environmental Protection Agency maximum contaminant level of 30 μg L. For the Rha-C12-C12 and Rha-C14-C14 collector ligands, decreasing the pH to 7 or below reduced the foam stability and quantity, such that these collectors were not suitable for treating this groundwater. To contextualize the results, a geochemical analysis of the groundwater was conducted, and a consideration of uranium speciation is described. Based on this study, the efficacy of monorhamnolipid-based ion flotation in real world groundwater has been demonstrated with suitable solution conditions and collectors identified.
Topics: Environmental Pollution; Groundwater; Humans; Mining; Uranium; Water Pollutants, Radioactive
PubMed: 34600421
DOI: 10.1016/j.jenvman.2021.113835 -
Scientific Reports Mar 2023During nuclear fuel processing, workers can potentially be exposed to repeated inhalations of uranium compounds. Uranium nephrotoxicity is well documented after acute...
During nuclear fuel processing, workers can potentially be exposed to repeated inhalations of uranium compounds. Uranium nephrotoxicity is well documented after acute uranium intake, but it is controversial after long-term or protracted exposure. This study aims to analyze the nephrotoxicity threshold after repeated uranium exposure through upper airways and to investigate the resulting uranium biokinetics in comparison to reference models. Mice (C57BL/6J) were exposed to uranyl nitrate (0.03-3 mg/kg/day) via intranasal instillation four times a week for two weeks. Concentrations of uranium in urines and tissues were measured at regular time points (from day 1 to 91 post-exposure). At each exposure level, the amount of uranium retained in organs/tissues (kidney, lung, bone, nasal compartment, carcass) and excreta (urine, feces) reflected the two consecutive weeks of instillation except for renal uranium retention for the highest uranium dose. Nephrotoxicity biomarkers, KIM-1, clusterin and osteopontin, are induced from day 4 to day 21 and associated with changes in renal function (arterial fluxes) measured using non-invasive functional imaging (Doppler-ultrasonography) and confirmed by renal histopathological analysis. These results suggest that specific biokinetic models should be developed to consider altered uranium excretion and retention in kidney due to nephrotoxicity. The threshold is between 0.25 and 1 mg/kg/day after repeated exposure to uranium via upper airways.
Topics: Mice; Animals; Uranium; Mice, Inbred C57BL; Kidney; Feces; Body Fluids
PubMed: 36914734
DOI: 10.1038/s41598-023-31073-1 -
Current Environmental Health Reports Jun 2024This review provides insights into resolving intergenerational issues related to the disposal of waste containing high amounts of uranium (uranium waste), from which... (Review)
Review
PURPOSE OF REVIEW
This review provides insights into resolving intergenerational issues related to the disposal of waste containing high amounts of uranium (uranium waste), from which distant future generations will have higher health risks than the current generation.
RECENT FINDINGS
Uranium (half-life: 4.5 billion years) produces various progeny radionuclides through radioactive decay over the long term, and its radioactivity, as the sum of its contributions, continues to increase for more than 100,000 years. In contrast to high-level radioactive wastes, protective measures, such as attenuation of radiation and confinement of radionuclides from the disposal facility, cannot work effectively for uranium waste. Thus, additional considerations from the perspective of intergenerational ethics are needed in the strategy for uranium waste disposal. The current generation, which has benefited from the use and disposal of uranium waste, is responsible for protecting future generations from the potential risk of buried uranium beyond the lifetime of a disposal facility. Fulfilling this responsibility means making more creative efforts to convey critical information on buried materials to the distant future to ensure that future generations can properly take measures to reduce the harm by themselves in response to changing circumstances including people's values.
Topics: Uranium; Humans; Radioactive Waste; Refuse Disposal
PubMed: 38538904
DOI: 10.1007/s40572-024-00442-x