The impacts of seawater acidification on Ruditapes philippinarum sensitivity to carbon nanoparticles
In the present study, the impacts of multi-walled carbon nanotubes (MWCNTs), one of the most important NMs used in broad industrial and biomedical applications, on the clam Ruditapes philippinarum were evaluated under actual and predicted ocean acidification conditions. For this, oxidative stress, metabolic capacity and neurotoxicity related biomarkers were measured after a long-term exposure of the clams to different conditions. The results obtained revealed that under low pH conditions the toxicity of MWCNTs was similar to the impacts measured under control pH. In both cases the energy-related responses in contaminated clams were altered with an increase of their metabolism which resulted in the expenditure of their energy reserves (lower glycogen content). Moreover, R. philippinarum showed oxidative stress when exposed to MWCNTs expressed by higher lipid peroxidation activity, a lower ratio between reduced and oxidized glutathione and activation of antioxidant defences and biotransformation mechanisms. Additionally, neurotoxicity was observed by inhibition of cholinesterase activity in organisms exposed to MWCNTs at both pH conditions.