Meat and Bone Meals (MBM) combustion residues (ashes) are calcium and phosphate-rich materials. The aim of this work is to evaluate ashes efficiency for remediation of cadmium-contaminated aqueous solutions, and to assess the bioavailability of cadmium on Xenopus laevis larvae. In this study both industrial (MBM-BA) and laboratory (MBM-LA) ashes are compared regarding their efficiency. Kinetic investigations reveal that cadmium ions are quickly immobilized, with a maximum cadmium uptake at 57 mg Cd2+/g of ashes for MBM-LA, two times higher than metal uptake quantity of MBM-BA, in our experimental conditions. Chemical and X-ray diffraction analysis (XRD) reveal that Cd2+ is mainly immobilized as Ca10-xCdx(PO4)(6)(OH)(2) by both ashes, whereas otavite, Cd(CO3), is also involved for MBM-LA in cadmium uptake. Otavite formation could be explained by the presence of carbonates in MBM-LA, as observed by W. Genotoxicity of cadmium solution on Xenopus larvae is observed at 0.02, 0.2 and 2 mg Cd2+/L However addition of only 0.1 g/L MBM-LA inhibits these effects for the above concentration values whereas Cd2+ bioaccumulation in larvae's liver is similar for both experiments, with and without ashes. (C) 2009 Elsevier B.V. All rights reserved.