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This study complements previous research on metal contamination of soils in the area historically affected by Zn smelting near Olkusz, southern Poland, and provides complex data on the geochemistry of anthropogenic Tl in soils with contrasting land use. Significant differences in Tl concentrations and chemical fractionation were observed between forest and grassland soil profiles indicating the effect of land use on Tl behaviour. It was found that forest soils have the ability to concentrate high amounts of Tl, particularly within the organic layers. A comparison of Tl concentrations in the upper and bottom horizons of forest and grassland soils clearly demonstrates vertical mobility of Tl. Sequential extraction results showed up to about 20% of total Tl amount was associated with exchangeable/acid-extractable fraction in forest soils, whereas the Tl concentrations in grassland soils were up to an order of magnitude lower. Taking into account dominant bonding of Tl to the residual fraction, Tl in grassland soils poses lower environmental hazard regarding potential mobilisation or uptake by plants., This study complements previous research on metal contamination of soils in the area historically affected by Zn smelting near Olkusz, southern Poland, and provides complex data on the geochemistry of anthropogenic Tl in soils with contrasting land use. Significant differences in Tl concentrations and chemical fractionation were observed between forest and grassland soil profiles indicating the effect of land use on Tl behaviour. It was found that forest soils have the ability to concentrate high amounts of Tl, particularly within the organic layers. A comparison of Tl concentrations in the upper and bottom horizons of forest and grassland soils clearly demonstrates vertical mobility of Tl. Sequential extraction results showed up to about 20% of total Tl amount was associated with exchangeable/acid-extractable fraction in forest soils, whereas the Tl concentrations in grassland soils were up to an order of magnitude lower. Taking into account dominant bonding of Tl to the residual fraction, Tl in grassland soils poses lower environmental hazard regarding potential mobilisation or uptake by plants.

Concentrations of Tl up to 0.8 mg/kg in trees affected by primary Zn smelting at Olkusz in southern Poland imply that pines tend to accumulate this metal to some extent. There was a generally positive relationship between Tl levels in soil and tree-rings, but patterns in the stem wood did not correspond to changes in Tl deposition; lateral translocation to the sapwood-heartwood boundary is suggested. In contract, tree-ring patterns for Zn and Cd showed significant correlation with their deposition. Pb isotope compositions of both trees and soils revealed the predominance of smelter emissions while the patterns of nutrient Ca, Mg and Mn in wood reflected environmental changes related to acid deposition., Concentrations of Tl up to 0.8 mg/kg in trees affected by primary Zn smelting at Olkusz in southern Poland imply that pines tend to accumulate this metal to some extent. There was a generally positive relationship between Tl levels in soil and tree-rings, but patterns in the stem wood did not correspond to changes in Tl deposition; lateral translocation to the sapwood-heartwood boundary is suggested. In contract, tree-ring patterns for Zn and Cd showed significant correlation with their deposition. Pb isotope compositions of both trees and soils revealed the predominance of smelter emissions while the patterns of nutrient Ca, Mg and Mn in wood reflected environmental changes related to acid deposition.