Effects of Copper Nanoparticles Exposure in the Mussel Mytilus galloprovincialis

CuO NPs are widely used in various industrial and commercial applications. However, little is known about their potential toxicity or fate in the environment. In this study the effects of copper nanoparticles were investigated in the gills of mussels Mytilus galloprovincialis, comparative to Cu2+. Mussels were exposed to 10 mu gCu.L-1 of CuO NPs and Cu2+ for 15 days, and biomarkers of oxidative stress, metal exposure and neurotcodcity evaluated. Results show that mussels accumulated copper in gills and responded differently to CuO NPs and Cu2+, suggesting distinct modes of action. CuO NPs induced oxidative stress in mussels by overwhelming gills antioxidant defense system, while for Cu2+ enzymatic activities remained unchanged or increased. CuO NPs and Cu2+ originated lipid peroxidation in mussels despite different antioxidant efficiency. Moreover, an induction of MT was detected throughout the exposure in mussels exposed to nano and ionic Cu, more evident in CuO NPs exposure. Neurotoxic effects reflected as AChE inhibition were only detected at the end of the exposure period for both forms of copper. In overall, these findings show that filter-feeding organisms are significant targets for nanoparticle exposure and need to be included when evaluating the overall toxicological impact of nanoparticles in the aquatic environment.