Depleted uranium mobility across a weapons testing site: Isotopic investigation of porewater, earthworms and soils

Oliver, I., Graham, M.C., MacKenzie, A., Ellam, R. and Farmer, J.G. (2008) Depleted uranium mobility across a weapons testing site: Isotopic investigation of porewater, earthworms and soils. Environmental Science and Technology, 42(24), pp. 9158-9164. (doi: 10.1021/es8013634)

Abstract

The mobility and bioavailability of depleted uranium (DU) in soils at a UK Ministry of Defence (UK MoD) weapons testing range were investigated. Soil and vegetation were collected near a test-firing position and at eight points along a transect line extending 200 m down-slope, perpendicular to the firing line, toward a small stream. Earthworms and porewaters were subsequently separated from the soils and both total filtered porewater (<0.2 μm) and discrete size fractions (0.2 μm−100 kDa, 100−30 kDa, 30−3 kDa, and <3 kDa) obtained via centrifugal ultrafiltration were examined. Uranium concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) for soils and ICP-mass spectrometry (MS) for earthworms and porewaters, while ²³⁵U:²³⁸U atom ratios were determined by multicollector (MC)-ICP-MS. Comparison of the porewater and earthworm isotopic values with those of the soil solids indicated that DU released into the environment during weapons test-firing operations was more labile and more bioavailable than naturally occurring U in the soils at the testing range. Importantly, DU was shown to be present in soil porewater even at a distance of 185 m from the test-firing position and, along the extent of the transect, was apparently associated with organic colloids.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Oliver, Dr Ian and Ellam, Professor Rob and MacKenzie, Professor Angus
• Authors: Oliver, I., Graham, M.C., MacKenzie, A., Ellam, R., and Farmer, J.G.
• Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Environmental Science and Technology
• Journal Abbr.: EST
• Publisher: American Chemical Society
• ISSN: 0013-936X
• ISSN (Online): 1520-5851
• Published Online: 07 November 2008