Bioaccumulation and in vivo formation of titanium dioxide nanoparticles in edible mussels

•Edible mussels can accumulate TiO2NPs if kept in water contaminated by TiO2NPs.•TiO2NPs can also be found in mussels kept in water contaminated by ionic Ti.•Potential in vivo formation of TiO2NPs occurs in mussels.•Mussels can eliminate more than 70% of TiO2NPs after 3 days’ depuration.•Non-depurated mussels may be a source of exposure to NPs for consumers.