4. Physico-chemical characterization of the soil-plant system

4.1 Sampling and analysis

Vegetable crops (vegetables, herbs, fruit) were sampled over the course of a single growing season at a stage of development corresponding to that of their usual consumption. Uneaten parts were removed, and preparation mimicked the practices of a meticulous consumer. After three washes, and peeling if necessary, the samples were dried, mechanically ground and analyzed for Cd and Pb concentrations.

Given the presumption of intra-plot variability in metal concentrations within vegetable gardens, soil samples were collected for each of the beds where vegetable plants were collected. For each bed, a composite soil sample was taken from around ten samples taken from the worked soil layer (0-20 cm). The soil samples were dried, sieved to...