Lead Isotopes Tracing the Origin of Lead in an Irrigated Agricultural Soil in Crete

Measurements of the concentrations and isotopic composition of Pb in soil fractions in an irrigated cultivated soil profile developed on Miocene sediments in Crete are used to estimate the significance of soil-derived versus man-induced sources. In soil samples, lead concentrations are 7.1 ± 1 μg/g at shallow depth (40 cm), and reach 9.1 μg/g near the surface (10 cm). 206Pb/207Pb values range from 1.20 in shallow samples to 1.19 in the uppermost samples. In all the samples, the isotopic composition of Pb in the residual soil fraction, i.e. essentially silicate Pb, is slightly more radiogenic than in the soil mobile fraction. Pb in the EDTA-extracted fraction is anthropogenic Pb issuing most probably from Pb emitted in Greece.