Airborne uranium
contamination [--] as revealed through elemental and isotopic analysis
of tree bark
D.
Bellis a, R. Ma a, N. Bramall a, C.W. McLeod a * c.w.mcleod@sheffield.ac.uk,
N. Chapman b and K. Satake c
a Centre
for Analytical Sciences, Department of Chemistry, University of Sheffield,
Dainton Building, Sheffield S3 7HF, UK
b
Department of Civil and Structural Engineering, University of Sheffield,
Mappin Street, Sheffield S1 5RD, UK
c
National Institute for Environmental Studies, Onogawa16-2, Tsukuba, Ibariki
305-0053, Japan
Received 28 April 2000; accepted 16 November 2000
Tree bark is an effective biomonitor for uranium, with isotopic analyses allowing discrimination between nuclear and non nuclear emissions.
Abstract
A new
strategy for characterisation of airborne uranium contamination based on
ICP mass spectrometric analysis of tree bark is described. The uranium
content of tree barks (50 samples) obtained from diverse locations (remote,
rural, industrial) varied over almost four orders of magnitude (0.001-8.3
µg/g U) with maximum concentrations recorded in the vicinity of a
nuclear fuel fabrication plant (0.70-8.3 µg/g U). Elevated concentrations
were also observed near a coal-fired power station (0.25-0.38 µg/g
U). Isotopic analysis revealed significant deviation from the natural uranium
isotope ratio (235U/238U, 0.00725) at four nuclear installations (235U/238
U, 0.0055-0.0097). These findings indicate that tree bark serves as an
effective biomonitor for uranium and, with isotopic analysis, discrimination
between nuclear and non-nuclear emissions is realised.
Keywords:
Uranium; Isotope ratio; Tree bark; ICP-Mass Spectrometry; Airborne pollution
*Corresponding author. Tel.: +44-114-222-3600; fax: +44-114-222-3650
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