Distribution of thallium and accompanying metals in tree rings of Scots pine ( Pinus sylvestris L.) from a smelter-affected area

Abstract

Distribution of Tl, Zn, Cd, Pb, K, Ca, Mg and Mn and Pb isotopic composition in tree rings of Scots pine ( Pinus sylvestris L.) from an area affected by primary Zn smelting (Olkusz, southern Poland) were investigated. Elevated concentrations of Tl (up to 0.8 mg kg −1) in pine trees imply that conifers tend to accumulate this metal to some extent. A generally positive relationship between soil and tree-ring Tl levels was identified. The Tl patterns in stem wood did not correspond to changes in Tl deposition; the lateral translocation of Tl in the sapwood and its accumulation at the sapwood-heartwood boundary (i.e., in the inner sapwood) is suggested. It is probable that the specific behavior of Tl in trees results from its biogeochemical analogy with K. In contrast, tree-ring patterns of Zn and Cd significantly correlated with their deposition; nevertheless, a partial shift of these metals towards the stem center cannot be excluded. The isotopic composition of Pb ( 206Pb/ 207Pb ~ 1.172–1.184) in trees and underlying soils revealed the predominant influence of smelter emissions ( 206Pb/ 207Pb ~ 1.17) on Pb contamination. Analysis of main nutrients (Ca, Mg and Mn) in wood reflected environmental changes related to acid deposition.