SIGNIFICANCE OF SOIL PROPERTIES FOR CONTENT AND DISTRIBUTION OF CADMIUM AND LEAD IN NATURAL CALCAREOUS SOILS

The total content of Cd and Pb in 30 natural (uncultivated and unpollu ted) calcareous soils from the province of Valladolid (Spain) were det ermined. The ranges of total Cd and Pb were 0.05-0.43 mu g g(-1) and 4 .44-50.34 mu g g(-1), respectively. Significant correlations were foun d between total Cd and carbonate contents (P < 0.05), between total Pb and organic matter (P < 0.01) and between total Pb and clay contents (P < 0.01). The mean contents of both elements were higher in the less developed soils (leptosols, regosols, fluvisols, solonchaks) than in the more developed ones (acrisols, cambisols, luvisols, solonetzs). Th is distribution is parallel to that of soil components for the accumul ation of Cd and Pb in the soils studied. In the distribution of both m etals and the other soil components in the soil profiles only there we re similarities between the distribution patterns of Pb and clay. (C) 1998 Elsevier Science B.V. All rights reserved.