To evaluate the contribution of digestive and epithelial transfer of Cd from soil to snail, Helix aspersa was exposed to an artificial substrate contaminated with 0,100,500, and 1000 microg Cd.g(-1) for 4 weeks under laboratory conditions. Two modes of exposure were used: (1) the snails were in direct contact with the substrate (DC) or (2) were separated from substrate with a perforated plate (no contact (NC)) which allowed ingestion of substrate but avoided epithelial contact. Cd concentrations in DC snails were twice as high as in NC snails. The bioaccumulation factors were 0.51+/-0.13 in DC snails and 0.26+/-0.04 in NC snails. Dose-dependent growth inhibition was noted in DC snails (500