title: Biogeochemical signatures in the lichen Hypogymnia physodes in the mid Urals.
abstract: Multi-element content and uranium (U) isotopes were investigated in the lichen Hypogymnia physodes (native and transplants) sampled across a 60-km transect, centred on Karabash smelter town, from Turgoyak Lake (SW) to Kyshtym (NE) to investigate the origin of U. Kyshtym was the site of a major nuclear accident in 1957. (234)U/(238)U activity ratios in native thalli sampled during July 2001 were within the natural isotopic ratio in minerals. Uranium/thorium (U/Th) ratios were higher in native thalli towards the NE (average 0.73) than those in the SW (average 0.57). Element signatures in native thalli and transplants suggest U was derived from fossil fuel combustion from Karabash and sources lying further to the east. Systematic and significant U enrichment indicative of a nuclear fuel cycle source was not detected in any sample. Element signatures in epiphytic lichen transplants and native thalli provide a powerful method to evaluate U deposition.
authors.affiliation: Department of Botany, Natural History Museum, Cromwell Road, London SW7 5BD, UK. w.purvis@nhm.ac.uk
authors.forename: O W
authors.initials: OW
authors.lastname: Purvis
authors.forename: J
authors.initials: J
authors.lastname: Longden
authors.forename: G
authors.initials: G
authors.lastname: Shaw
authors.forename: P D J
authors.initials: PD
authors.lastname: Chimonides
authors.forename: T E
authors.initials: TE
authors.lastname: Jeffries
authors.forename: G C
authors.initials: GC
authors.lastname: Jones
authors.forename: I N
authors.initials: IN
authors.lastname: Mikhailova
authors.forename: B J
authors.initials: BJ
authors.lastname: Williamson
mesh_terms: D016000:Cluster Analysis; D004190:Disasters / Q000706:statistics & numerical data*; D008011:Lichens / Q000737:chemistry*; D013058:Mass Spectrometry; D025341:Principal Component Analysis; D011834:Radiation Monitoring / Q000706:statistics & numerical data*; D012426:Russia; D013054:Spectrophotometry, Atomic; D014501:Uranium / Q000032:analysis*
chemical_list: D014501:Uranium