International standardized procedures for in vivo evaluation of multi-walled carbon nanotube toxicity in water

ABSTRACT

The classical approach in ecotoxicological evaluation of chemical substances consists of conducting standardized bioassays on organism models. In this work, the potential impact of industrial multi-walled carbon nanotubes was investigated by ecotoxicological standardized procedures using aquatic organisms of different trophic levels, namely bacteria, green algae, invertebrates, fish, and amphibians. The results indicated (1) inhibition of growth in amphibians at 50 mg L⁻¹ and higher, and (2) no effects on daphnia and fish up to 100 mg L⁻¹. With the exception of algae (for which Fe deficiency is measured), it seems that the observed toxicity may be due to physiological effects in relation to the ingestion of carbon nanotubes not necessarily related to their intrinsic effects.

KEYWORDS:

• Multi-walled carbon nanotubes
• ecotoxicity
• standardized bioassays
• bacteria
• algae
• fish
• amphibians

Acknowledgments

The authors acknowledge Annie Perrault and Floriane Bourdiol for their technical help. Thanks to the Groupement de Recherche de Lacq (ARKEMA) for MWNTs suspensions and technical help. We are also indebted to Michel Lagoin (Université Paul Sabatier, Toulouse, France) for reviewing the English version of the manuscript and to the language services of Elsevier.

Disclosure statement

Part of this research has been developed in the framework of the French collaborative laboratory NAUTILE (Nanotubes et Ecotoxicologie), which is the first public/private joint laboratory dedicated to the study of the ecotoxicological impact of CNTs in the aquatic environment. The framework agreement was signed by (1) Arkema France, (2) Centre National de la Recherche Scientifique (CNRS), (3) Institut National Polytechnique de Toulouse (INPT), and (4) Université Paul Sabatier (UPS) of Toulouse in September 2010. The authors declare no competing financial interests or conflict of interest.