Depleted uranium chemical toxicity

Hartmann, H.M., Monette, F.A., Avci, I.H. (2000). Overview of toxicity data and risk assessment methods for evaluating the chemical effects of depleted uranium compounds. Hum. Ecol. Risk Assess. 6 851-74. 

Uranium is a heavy metal that forms compounds and complexes of different varieties and solubilities. The chemical action of all isotopes and isotopic mixtures of uranium is identical, regardless of the specific activity (i.e., enrichment), because chemical action depends only on chemical properties. Thus, the chemical toxicity of a given amount or weight of natural, depleted, and enriched uranium is identical. 

UNSCEAR has considered that limits for natural (and depleted) uranium in food and drinking water (the most important sources of human exposure) should be based on the chemical toxicity rather than on a hypothetical radiological toxicity, which has not been observed in either humans or animals (UNSCEAR 1993 Wrenn et al. 1985). 

Chemically, natural and depleted uranium are identical. Therefore, the MRLs calculated for chemical effects, based on studies that tested natural uranium, are applicable to the chemical actions of depleted uranium because the nature and extent of chemical toxicity are determined only by chemical properties. 

Contamination means the presence of radioactive material on a surface in quantities in excess of 0.4 Bq/cm (10 pCi/cm ) for beta and gamma emitters and low-toxicity alpha emitters, or 0.04 Bq/cm (lO" pCi/cm ) for all other alpha emitters. Low-toxicity alpha emitters are natural uranium depleted uranium uranium-235 uranium-238 natural thorium thorium-232 thorium-228 and thorium-230 when contained in ores, or physical or chemical concentrates or radionuclides with a half-life of less than 10 days. IMO Class 7,2.8.1... 

To simulate the nuclear waste, U02(N03)2 6H20 dissolved in nitric acid solution was used. U02(N03)2 6H20 is a yellow crystalline solid. It contains nitric acid and is mildly chemically toxic. It is non-fissile (depleted) uranium, containing less than 1.0 % U-235, which means that it cannot sustain a nuclear chain reaction. It is radioactive, but chemically stable. Some of the properties are presented in Table 3.4. At all experiments the initial concentration of dioxouranium(VI) in the nitric acid solutions was 0.05 M. The concentration of IJ02 in the two phases was detected by a UV-Vis spectrometer (USB2000+, from Ocean Optics). 

The biological environment may be disrupted in many ways as a result of weapons technologies. Nuclear weapons production, testing, use, and disposal may release ionizing radiation shells hardened with depleted uranium also release ionizing radiation. Conventional and chemical weapons may release toxic substances... 

Domingo JL (1995) Chemical toxicity of uranium. Toxicol Ecotoxicol News 2 74-78 Pellmar TC, FudareUi AF, Ejnik JW, Hamilton M, Hogan JB, Strocko S, Emond C, Laundauer M (1999) Toxicological evaluation of depleted uranium in rats implanted with depleted uranium pellets. Toxicol Sci 49 29-39... 

DU is stored as UFeor it is de-converted back to UsOg, which is more benign chemically and thus more suited for long-term storage. It is also less toxic. Every year, approximately 60,000 t of depleted uranium joins already substantial stockpiles in the United States, Europe, and Russia. The world stock is about 1.7 million tonnes. 

Low-toxicity alpha emitters are natural uranium depleted uranium natural thorium uranium or uranium thorium thorium , and thorium ° when contained in ores or physical and chemical concentrates and alpha emitters with a half-life of <10 days. 

Uranium production does have a notable impact on ozone depletion. The Environmental Protection Agency s (EPA) Toxic Release Inventory showed that in 1999, the nation s two commercial nuclear fuel-manufacturing plants released 88% of the ozone-depleting chemical CFC-11 by industrial sources in the U.S. and 14% of the discharges in the whole world. 

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