THE CONCENTRATIONS OF SOME SCANDIUM SUBGROUP TRACE-METALS IN SOILS OF POLAND

A survey was conducted to establish baseline contents of Ce, La, Nd, Sc, Th, Y, Yb (metals of the IIIB group of the periodic table of elements) in the surface soils of Poland. The sampling programme was designed to obtain data representative (n = 130) of arable soils in Poland, under typical management. Locations directly affected by pollution (point source pollution, roads with heavy traffic, etc.) were avoided. The metal concentrations in the soil samples were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Since frequency distributions of the metal contents of the soils were positively skewed, the data were transformed to logarithms (base 10) and central tendency and variation were expressed as geometric means (GM) and geometric deviations (GD), respectively. Mean concentrations of the metals (in mg/kg, dry weight) in the soil samples studied were: Ce 22.7, La 11.9, Nd 9.9, Sc 2.6, Th 3.5, Y 6.5, and Yb 0.9. The metal contents of the soils correlated very well (r is 0.90-0.96) with amounts of particles < 0.02 mm diameter, and with concentrations of Al and Fe, which indicate that the occurrence of the metals in the soils is controlled by pedogenic factors. All the metals studied had significantly (P < 0.05) higher concentrations in silty and loamy soils, considered as one group, than in sandy soils.