Uptake, accumulation, and biotransformation of metal oxide nanoparticles by a marine suspension-feeder

• Published in: Journal of hazardous materials 2012-07, Vol.225-226, p.139-145
• Main Authors: Montes, Milka O., Hanna, Shannon K., Lenihan, Hunter S., Keller, Arturo A.
• Format: Article
• Language: English
• Subjects: Animals; Bioaccumulation; Biotransformation; CeO2; Cerium - metabolism; Ecosystems; Feces - chemistry; Marine; Marine fate and transport; Metal Nanoparticles; Mussels; Mytilus - metabolism; Mytilus galloprovincialis; Nanomaterials; Nanostructure; Scanning electron microscopy; Transport; Water Pollutants, Chemical - metabolism; Zinc; Zinc Oxide - metabolism; ZnO
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2012.05.009

► Suspension-feeding by mussels can greatly alter mobility and fate of metal oxide nanoparticles. ► Bioprocessing of metal oxide nanoparticles by mussels removes large fraction from water column. ► Mussels repackage metal oxide nanoparticles in highly concentrated pseudofeces. ► Novel biological pathway between major compartments in marine systems. ► Very different outcome for ZnO and CeO2 nanoparticles based on their solubility. A growing body of evidence indicates that some engineered nanoparticles (ENPs) are toxic to organisms that perform important ecosystem services in terrestrial and aquatic ecosystems. However, toxicity can be influenced by the biotransformation of contaminants, including ENPs, as it may alter the fate and transport of these substances. In turn, fate and transport can influence their bioavailability. To understand how biotransformation influences the fate and transport of ENPs in marine ecosystems, we exposed suspension-feeding mussels, Mytilus galloprovincialis, to two common nano-metal oxides, CeO2 and ZnO, over a range of concentrations from 1mgL−1 to 10mgL−1, in a laboratory experiment. Mussels exposed to 10mgL−1 accumulated 62μgg−1 of Ce and 880μgg−1 of Zn on a dry tissue basis but rejected 21,000μgg−1 for Ce and 63,000μgg−1 for Zn in pseudofeces. Scanning electron microscope evidence indicates CeO2 remained as ENPs but ZnO did not after being rejected by the mussels. Mussels filtered most of the CeO2 from the aqueous media, while a significant fraction of Zn remained in solution. Differences in ENP solubility affect ENP uptake, excretion, and accumulation in mussels. Our study highlights the potential role of marine suspension feeders in biotransformation of ENPs.