Determining the fate of depleted uranium

Battlefield use of depleted uranium (DU) weapons has generated considerable controversy because of the potential long-term effects on the environment and on the health of people exposed to it. DU projectiles have been used as armour-piercing weapons by both the British and American militaries and deployed in the Balkans and both Gulf wars. Upon impact the metal combusts and a fraction is dispersed as uranium oxide particulates. Inhalation of these particulates constitutes the main long-term risk to humans.

From 1958 to 1984 a plant in Colonie, USA was used for processing uranium and manufacturing weapons and radiation shielding, which led to the release of uranium oxide particulates into the local environment. Scientists from the University of Leicester and the British Geological Survey have been using Diamond to study particles from the region around the Colonie plant to determine whether they can be used to predict the environmental fate of battlefield contamination sites. Their work has been published in Mineralogical Magazine.

Uraniferous particles collected from dust and soil around the Colonie plant were analysed by scanning electron microscopy, energy-dispersive X-ray analysis (SEM-EDXA) and microfocus extended X-ray absorption fine structure (μEXAFS). Despite the particles having been in the environment for over 25 years, most were found to have remained intact since they were produced, with only a few showing evidence of corrosion and minor dissolution. The particles were identified as polycrystalline and often hollow microscopic spheres, similar to those produced by depleted uranium weapons piercing armoured targets. This supports the use of Colonie as a comparison for battlefield sites.

The group looked at the uranium speciation in samples from the Colonie site. This is relevant to understanding the bioaccessibility and mobility of particulates. They found that the dominant species in particles is U4+, which has limited bioaccessibility and mobility.

Dr Nick Lloyd, formerly of the University of Leicester, took part in the study.

The morphologies and compositions of depleted uranium particles from an environmental case-study, N. S. Lloyd, J. F. W. Mosselmans, R. R. Parrish, S. R. N. Chenery, S. V. Hainsworth and S. J. Kemp Mineralogical Magazine; September 2009; v. 73; no. 3; p. 495-510;
DOI: 10.1180/minmag.2009.073.3.495