THE SPATIAL-DISTRIBUTION OF LEAD CONCENTRATIONS IN THE AGRICULTURAL SOILS AND MAIN CROP PLANTS IN POLAND

This paper presents Pb concentrations in Poland's soils, in grain of c ereal plants, and in roots or tubers of root plants, and examines the spatial distribution of these concentrations. The overall geometric me ans of Pb concentrations in the soils, cereals, and root plants were 1 6.4, 0.25 and 0.54 mg/kg, respectively. Spatial distribution of the da ta revealed that level of Pb in the soils in SW-W Poland was significa ntly higher than in the NE-E and central regions, apparently as a resu lt of the impact of contamination from various sources. About 81% of t he studied soils had natural concentrations of Pb; 16% had the metal c oncentrations higher than normal but lower than 100 mg/kg (limit conce ntration), and 3% of the soils had Pb concentrations over 100 mg/kg. L ead concentrations in the crops did not follow the pattern of the spat ial distribution of Pb content of the soils, which was also expressed by the lack of correlation between the metal content of the soils and plants. Around 10% of the samples of cereal plants and 30% of root pla nts were found to have elevated levels of Pb. The proportion of Pb cer eal grain samples with elevated Pb concentrations was greater in the N E-E region of the country (23%) than in central and SW-W Poland (6-8%) . In contrast, more root plant samples contaminated with lead were fou nd in the SW-W than in the NE-E part of the country.