Radiological toxicity of Depleted Uranium
Background: The military use of depleted uranium (DU) and/or recycled uranium (RU) has given rise to public concern as to the impact on public health of exposure to environmental sources. Exposure to soluble natural uranium, through drinking water and the food chain, is ubiquitous. After military use, DU / RU are present in the environment either as metal or as oxide dusts. Due to the low specific activity of uranium, the potential effects of exposure are generally attributed to chemical toxicity. Insoluble particulates may be an exception.
Results: DU/RU dusts are a mixture of oxides of differing solubility, such that, if retained in the lung, partial dissolution occurs over the time scale of about a month. As DU has been shown to be capable of transforming human cells to a tumourigenic phenotype without the involvement of radiation, such particles present a unique radiological/chemical toxic hazard. The bystander effect may be of relevance where an alpha-particle emitter of low specific activity is distributed over the lung.
Conclusions: The health risks of exposure to DU/RU are likely to be only partially reflected by the radiation dose per received. Further work on the chemical transforming ability of DU, the potential for an interaction between its chemical and radiological toxicities and the significance of the bystander effect in this context is required to fully estimate the public health significance of exposure to DU/RU.
Published on 5 November 2001.
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