Depleted Uranium and Human Health Faa, Armando; Gerosa, Clara; Fanni, Daniela ...
Current medicinal chemistry,
01/2018, Letnik:
25, Številka:
1
Journal Article
Recenzirano
Depleted uranium (DU) is generally considered an emerging pollutant, first extensively introduced into environment in the early nineties in Iraq, during the military operation called "Desert Storm". ...DU has been hypothesized to represent a hazardous element both for soldiers exposed as well as for the inhabitants of the polluted areas in the war zones. In this review, the possible consequences on human health of DU released in the environment are critically analyzed. In the first part, the chemical properties of DU and the principal civil and military uses are summarized. A concise analysis of the mechanisms underlying absorption, blood transport, tissue distribution and excretion of DU in the human body is the subject of the second part of this article. The following sections deal with pathological condition putatively associated with overexposure to DU. Developmental and birth defects, the Persian Gulf syndrome, and kidney diseases that have been associated to DU are the arguments treated in the third section. Finally, data regarding DU exposure and cancer insurgence will be critically analyzed, including leukemia/lymphoma, lung cancer, uterine cervix cancer, breast cancer, bladder cancer and testicular cancer. The aim of the authors is to give a contribution to the debate on DU and its effects on human health and disease.
Reaction of U(TrenTIPS) 1, TrenTIPS=N(CH2CH2NSiiPr3)3 with 0.25equivalents of P4 reproducibly affords the unprecedented actinide inverted sandwich cyclo-P5 complex {U(TrenTIPS)}2(µ-η5:η5-cyclo-P5) ...(2). All prior examples of cyclo-P5 are stabilized by d-block metals, so 2 shows that cyclo-P5 does not require d-block ions to be prepared. Although cyclo-P5 is isolobal to cyclopentadienyl, which usually bonds to metals via σ- and π-interactions with minimal delta-bonding, theoretical calculations suggest the principal bonding in the U(P5)U unit is polarized delta-bonding. Surprisingly, the characterization data are overall consistent with charge transfer from uranium to the cyclo-P5 unit to give a cyclo-P5 charge state that approximates to a dianionic formulation. This is ascribed to the larger size and superior acceptor character of cyclo-P5 compared to cyclopentadienyl, the strongly reducing nature of uranium(III), and the availability of uranium delta-symmetry 5f orbitals.
Uranium certified reference materials (CRM) issued by New Brunswick Laboratory were subjected to dating using four independent uranium-series radiochronometers. In all cases, there was acceptable ...agreement between the model ages calculated using the .sup.231Pa-.sup.235U, .sup.230Th-.sup.234U, .sup.227Ac-.sup.235U or .sup.226Ra-.sup.234U radiochronometers and either the certified .sup.230Th-.sup.234U model date (CRM 125-A and CRM U630), or the known purification date (CRM U050 and CRM U100). The agreement between the four independent radiochronometers establishes these uranium certified reference materials as ideal informal standards for validating dating techniques utilized in nuclear forensic investigations in the absence of standards with certified model ages for multiple radiochronometers.
The central goal of this design is to meet U.S. demand for the medical isotope .sup.99Mo with a water-cooled critical reactor featuring discrete, cladded fuel elements. .sup.99Mo is produced within ...the solid fuel that is powering the fission reaction. The fuel is a low-enriched uranyl nitrate hexahydrate crystal, chosen to take advantage of a flexible uranium recovery process. The low melting temperature of the fuel material has required utilizing an annular fuel pin geometry. Preliminary heat transfer calculations and MCNP modeling have demonstrated the capability of such a design to produce the desired quantities of .sup.99Mo.
Downwindis an unflinching tale of the atomic West that reveals the intentional disregard for human and animal life through nuclear testing by the federal government and uranium extraction by mining ...corporations during and after the Cold War.
Sarah Alisabeth Fox highlights the personal cost of nuclear testing and uranium extraction in the American West through extensive interviews with "downwinders," the Native American and non-Native residents of the Great Basin region affected by nuclear environmental contamination and nuclear-testing fallout. These downwinders tell tales of communities ravaged by cancer epidemics, farmers and ranchers economically ruined by massive crop and animal deaths, and Native miners working in dangerous conditions without proper safety equipment so that the government could surreptitiously study the effects of radiation on humans.
In chilling detailDownwindbrings to light the stories and concerns of these groups whose voices have been silenced and marginalized for decades in the name of "patriotism" and "national security."
With the renewed boom in mining in the American West, Fox's look at this hidden history, unearthed from years of field interviews, archival research, and epidemiological studies, is a must-read for every American concerned about the fate of our western lands and communities.
Between 1958 and 1982, NL Industries manufactured components of enriched (EU) and depleted uranium (DU) at a factory in Colonie NY, USA. More than 5 metric tons of DU was deposited as microscopic DU ...oxide particles on the plant site and surrounding residential community. A prior study involving a small number of individuals (n=23) indicated some residents were exposed to DU and former workers to both DU and EU, most probably through inhalation of aerosol particles.
Our aim was to measure total uranium U and the uranium isotope ratios: 234U/238U; 235U/238U; and 236U/238U, in the urine of a cohort of former workers and nearby residents of the NLI factory, to characterize individual exposure to natural uranium (NU), DU, and EU more than 3 decades after production ceased.
We conducted a biomonitoring study in a larger cohort of 32 former workers and 99 residents, who may have been exposed during its period of operation, by measuring Total U, NU, DU, and EU in urine using Sector Field Inductively Coupled Plasma - Mass Spectrometry (SF-ICP-MS).
Among workers, 84% were exposed to DU, 9% to EU and DU, and 6% to natural uranium (NU) only. For those exposed to DU, urinary isotopic and U compositions result from binary mixing of NU and the DU plant feedstock. Among residents, 8% show evidence of DU exposure, whereas none shows evidence of EU exposure. For residents, the U geometric mean is significantly below the value reported for NHANES. There is no significant difference in U between exposed and unexposed residents, suggesting that U alone is not a reliable indicator of exposure to DU in this group.
Ninety four percent of workers tested showed evidence of exposure to DU, EU or both, and were still excreting DU and EU decades after leaving the workforce. The study demonstrates the advantage of measuring multiple isotopic ratios (e.g., 236U/238U and 235U/238U) over a single ratio (235U/238U) in determining sources of uranium exposure.
•Biomonitoring study of residents and former workers exposed to DU in Colonie NY.•Urine (99 residents+32 former workers) analyzed for depleted uranium (DU).•DU detected in 84% of workers and 8% of residents >30 years after plant closed.•Enriched uranium detected in 6% of former workers based on isotope ratios.
The results of the atomistic simulation of a superionic transition and melting of uranium dioxide are presented. The temperature dependences of the concentration of defects in the oxygen sublattice ...and changes in the heat capacity and isothermal compressibility upon the superionic transition are calculated. It is shown that the curve of the superionic transition in the PT diagram can be described by the Ehrenfest's equation. The possibility of describing the superionic transition within the framework of the theory of second-order phase transitions is discussed. Based on the results obtained, it is considered that this structural transformation can occur in other materials.
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