The content and solubility of lead in arable soils of the Podlasie Province (eastern Poland)

The aim of the study was the estimation of total content of lead and its fraction in arable soils and permanent grassland of Podlasie Province, eastern Poland. The research material included 104 soil samples from Podlasie Province, which were collected in years 2011–2013 from the topsoil (0–30 cm) after plant harvest. The following basic physicochemical properties of soil samples were determined: granulometric composition, organic carbon content and pH in 1 mol·dm−3 KCl solution. Based on the granulometric composition soils were divided into three groups: very light and light, medium and organic soils. The total lead and its content in fractions was determined by means of GFAAS technique using Varian AA-100 apparatus. The fractions of lead were extracted by BCR method. In the case of very light and light soils the lowest percentage share of Pb on average was noted in exchangeable fraction (16.3% of total content) and the highest in fraction bound to Fe/Mn oxides (43.5%). Similarly in medium and organic soils the highest amount of Pb was stated in reducible fraction, 43.7 and 41.3% of total content, respectively, and the lowest in exchangeable fraction, 16.5 and 12.2%, respectively. It was found that content of total lead was typical for arable uncontaminated soils