Assessment of the potentialin vivoecotoxicity of Double-Walled Carbon Nanotubes (DWNTs) in water, using the amphibianAmbystoma mexicanum

Abstract

Because of their specific properties (mechanical, electrical, etc), carbon nanotubes (CNTs) are being assessed for inclusion in many manufactured products. Due to their massive production and number of potential applications, the impact of CNTs on the environment must be taken into consideration. The present investigation evaluates the ecotoxic potential of CNTs in the amphibian larvae (Ambystoma mexicanum ). Acute toxicity and genotoxicity were analysed after 12 days of exposure in laboratory conditions. The genotoxic effects were analysed by scoring the micronucleated erythrocytes in the circulating blood of the larvae according to the French standard micronucleus assay. The results obtained in the present study demonstrated that CNTs are neither acutely toxic nor genotoxic to larvae whatever the CNTs concentration in the water, although black masses of CNTs were observed inside the gut. In the increasing economical context of CNTs, complementary studies must be undertaken, especially including mechanistic and environmental investigations.

Chronic Toxicity of Double-Walled Carbon Nanotubes to Three Marine Organisms: Influence of Different Dispersion Methods

“…Induction of defense mechanisms may divert energy otherwise used for reproduction or development [28]. Confusion of DWNTs with food particles may also have contributed to the adverse effects previously mentioned by lowering the food intake efficiency of T. japonicus, as this was also found in other copepod [11] as well as with similar DWNT samples in the case of amphibians [29,30]. The present results also confirmed that DWNTs were not only ingested by T. japonicus but also observed inside their gut cells.…”

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

“…Concerning the absence of genotoxicity in erythrocytes of Xenopus larvae, the present results are in agreement with the previous ones obtained on amphibian larvae in the same conditions of exposure to MWNTs (Mouchet et al 2010) and DWNTs (Mouchet et al 2007(Mouchet et al , 2008. The majority of the time, if acute and chronic toxicities are generally observed after CNTs exposure of different biological models, genotoxicity, especially via micronucleus induction mechanism, is not demonstrated.…”

“…Cheng, Flahaut, and Cheng (2007) observed hatching delay in fish eggs exposed to 120 mg L ¡1 of raw SWNTs and 240 mg L ¡1 of raw DWNTs. Neither mortality nor growth inhibition was observed in urodele amphibian larvae up to 1 g L ¡1 of raw DWNTs (Mouchet et al 2007), whereas mortality was observed at 50 mg L ¡1 and growth inhibition from 10 mg L ¡1 in anuran amphibian larvae exposed to raw DWNTs (Mouchet et al 2008(Mouchet et al , 2011 as well as growth inhibition at 50 mg L ¡1 for raw MWNTs exposure (Mouchet et al 2010). Kahru and Dubourguier (2011) calculated on the basis of 34 median values a L(E)C 50 between 1 and 10 mg L ¡1 for SWNTs and MWNTs (L(E)C 50 derived from 77 individual values.…”

Systematic Consideration of Parameter Uncertainty and Variability in Probabilistic Species Sensitivity Distributions

“…Daphnia magna was shown to be the species most sensitive to CNTs; the lowest NOEC found for this organism was 13 μg/L –1 by Zhu et al (). The amphibian Ambystoma mexicanum presented an NOEC of 105 μg/L –1 (Mouchet et al ) and was the least sensitive species. The PNEC empirical probability distribution obtained from the PSSD had a mean of 86 μg/L –1 with 25th and 75th quantiles of 32 and 111 μg/L –1 , respectively (Table ).…”