Résumé
Because of their outstanding properties, carbon nanotubes (CNTs) are being assessed for inclusion in many manufactured products. Due to theirmassive production and growing number of potential applications, the impact of CNTs on the environment must be taken into consideration.The present investigation evaluates the ecotoxicological potential of double-walled carbon nanotubes (DWNTs) in the amphibian larvae Xenopuslaevis at a large range of concentrations in water (from 10 to 500 mg L−1). Acute toxicity and genotoxicity were analysed after 12 days of staticexposure in laboratory conditions. Acute toxicity was evaluated according to the mortality and the growth of larvae. The genotoxic effects wereanalysed by scoring the micronucleated erythrocytes of the circulating blood of larvae according to the International Standard micronucleus assay.Moreover, histological preparations of larval intestine were prepared after 12 days of exposure for observation using optical and transmissionelectron microscopy (TEM). Finally, the intestine of an exposed larva was prepared on a slide for analyse by Raman imaging.The results showed no genotoxicity in erythrocytes of larvae exposed to DWNTs in water, but acute toxicity at every concentration of DWNTsstudied which was related to physical blockage of the gills and/or digestive tract. Indeed, black masses suggesting the presence of CNTs wereobserved inside the intestine using optical microscopy and TEM, and confirmed by Raman spectroscopy analysis. Assessing the risks of CNTsrequires better understanding, especially including mechanistic and environmental investigations.