A marine mesocosm study on the environmental fate of silver nanoparticles and toxicity effects on two endobenthic species: The ragworm Hediste diversicolor and the bivalve mollusc Scrobicularia plana
Résumé
Silver nanoparticles are widely used in a range of products and processes for their antibacterial properties, electrical and thermal conductivity. The fate and effects of Ag nanoparticles were examined in two endobenthic species (Scrobicularia plana, Hediste diversicolor), under environmentally realistic conditions in outdoor mesocosmsexposed to Ag at 10 μg L−1 in nanoparticulate (Ag NPs) or soluble salt (AgNO3) forms for 21 days. Labile Ag wasdetermined in water and sediment by using diffusive gradient in thin films. Ag levels were equivalent in contaminated Ag NPs mesocosms to those contaminated with the soluble form. Bioaccumulation of Ag was observed forboth species exposed to either Ag in the nanoparticulate or ionic forms. Concerning biomarker responses, bothsoluble and nanoparticulate Ag forms, induced defenses against oxidative stress, detoxification, apoptosis,genotoxicity and immunomodulation. Nevertheless, DNA damages measured by the comet assay in the digestivegland of S. plana, and Phenoloxidase and lysozyme activities in S. plana and H. diversicolor, respectively, werehigher in the presence of Ag NPs compared to soluble Ag suggesting a specific nano effect.