The spatial distribution of lead concentrations in the agricultural soils and main crop plants in Poland

This paper presents Pb concentrations in Polandʹs soils, in grain of cereal plants, and in roots or tubers of root plants, and examines the spatial distribution of these concentrations. The overall geometric means of Pb concentrations in the soils, cereals, and root plants were 16.4, 0.25 and 0.54 mg/kg, respectively. Spatial distribution of the data revealed that level of Pb in the soils in SW-W Poland was significantly higher than in the NE-E and central regiobs, apparently as a result of the impact of contamination from various sources. About 81% of the studied soils had natural concentrations of Pb; 16% had the metal concentratiobs higher than normal but lower than 100 mg/kg (limit concentration), and 3% of the soils had Pb concentrations over 100 mg/kg. Lead concentrations in the crops did not follow the pattern of the spatial distribution of Pb content of the soils, 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 plants were found to have elevated levels of Pb. The proportion of Pb cereal grain samples with elevated Pb concentrations was greater in the NE-E region of the century (23%) than in central and SW-W Poland (6–8%). In contrast, more root plant samples contaminated with lead were found in the SW-W than in the NE-E part of the country.