PARENT SESSION

1J - Bioaccumulation
Hall 9
8:30 AM - 12:30 PM, Wednesday, 30 April 2003
Chair: Tarazona, J.¹, ¹
Co-chair: Gobas, F.², ²

(WE9/5) Transfer of metallic trace elements (Cd, Cu, Ni, Pb and Zn) in a soil—plant—invertebrate food chain: a microcosm study.

Scheifler, Renaud¹, de Vaufleury, Annette¹, Crini, Nadia¹, Badot, Pierre-Marie¹, ¹ University of Franche-Comté, Besançon, Franche-Comté, France

ABSTRACT- In this study, stainless steel cylindrical microcosms were developed and used in laboratory conditions to evaluate the transfer of five metallic trace elements (MTE), Cd, Cu, Ni, Pb and Zn, in a simplified food chain "soil—plant (lettuce Lactuca sativa)—invertebrate (snail Helix aspersa)". Two field agricultural soils were used, an unpolluted one and a contaminated one. Lettuce was cultivated for 8 weeks, and then snails were introduced into the microcosms (M-snails) and exposed for the 8 following weeks. In parallel experiments, snails were reared in containers (C-snails) without soil and were exposed only to lettuce leaves, which were cultivated on the unpolluted or the polluted soil used in the microcosm experiment. Snail tissues were analysed for MTE concentrations after 4 weeks of exposure in unpolluted systems and after 2, 4 and 8 weeks in polluted systems. After 4 weeks of exposure, concentrations in snails exposed to polluted systems were much higher than those measured in snails exposed to unpolluted systems, except for Cu and Ni. Cd and Zn concentrations in snails exposed to polluted environment showed a regular increase over time, Pb concentrations rapidly increased in the first 2 weeks and then remained stable, Cu concentrations remained stable during all experiment and Ni concentrations rapidly decreased in the first 2 weeks. Comparison concentrations between M- and C-snails allowed estimating the relative contribution of soil and plant in the total bioaccumulation in snail tissues. Contribution of soil in Cd accumulation was not consistent over time. The contribution of soil was higher than 80% for Pb and around 30% for Zn for all exposure durations.

Key words: transfer, food chain, metallic trace element, microcosm