title: Cerium oxide nanoparticles induce oxidative stress in the sediment-dwelling amphipod Corophium volutator.
abstract: Cerium oxide nanoparticles (CeO2 NPs) exhibit fast valence exchange between Ce(IV) and Ce(III) associated with oxygen storage and both pro and antioxidant activities have been reported in laboratory models. The reactivity of CeO2 NPs once they are released into the aquatic environment is virtually unknown, but this is important to determine for assessing their environmental risk. Here, we show that amphipods (Corophium volutator) grown in marine sediments containing CeO2 NPs showed a significant increase in oxidative damage compared to those grown in sediments without NPs and those containing large-sized (bulk) CeO2 particles. There was no exposure effect on survival, but significant increases in single-strand DNA breaks, lipid peroxidation and superoxide dismutase activity were observed after a 10-day exposure to 12.5 mg L(-1) CeO2. Characterisation of the CeO2 NPs dispersed in deionised or saline exposure waters revealed that more radicals were produced by CeO2 NPs compared with bulk CeO2. Electron energy loss spectroscopy (EELS) analysis revealed that both CeO2 NPs were predominantly Ce(III) in saline waters compared to deionised waters where they were predominantly Ce(IV). In both types of medium, the bulk CeO2 consisted mainly of Ce(IV). These results support a model whereby redox cycling of CeO2 NPs between Ce(III) and Ce(IV) is enhanced in saline waters, leading to sublethal oxidative damage to tissues in our test organism.
authors.affiliation: a Department of Biosciences , College of Life and Environmental Sciences, The Geoffrey Pope Building, University of Exeter , Exeter , UK .
authors.forename: Yuktee
authors.initials: Y
authors.lastname: Dogra
authors.affiliation: b Department of Geography , Earth and Environmental Sciences, Facility for Environmental Nanoscience Analysis and Characterisation, University of Birmingham , Edgbaston , Birmingham , UK .
authors.forename: Kenton P
authors.initials: KP
authors.lastname: Arkill
authors.affiliation: b Department of Geography , Earth and Environmental Sciences, Facility for Environmental Nanoscience Analysis and Characterisation, University of Birmingham , Edgbaston , Birmingham , UK .
authors.forename: Christine
authors.initials: C
authors.lastname: Elgy
authors.affiliation: b Department of Geography , Earth and Environmental Sciences, Facility for Environmental Nanoscience Analysis and Characterisation, University of Birmingham , Edgbaston , Birmingham , UK .
authors.forename: Bjorn
authors.initials: B
authors.lastname: Stolpe
authors.affiliation: b Department of Geography , Earth and Environmental Sciences, Facility for Environmental Nanoscience Analysis and Characterisation, University of Birmingham , Edgbaston , Birmingham , UK .|c Centre for Environmental Nanoscience and Risk, University of South Carolina , CA , USA , and.
authors.forename: Jamie
authors.initials: J
authors.lastname: Lead
authors.affiliation: b Department of Geography , Earth and Environmental Sciences, Facility for Environmental Nanoscience Analysis and Characterisation, University of Birmingham , Edgbaston , Birmingham , UK .|d Department of Geography , Earth and Environmental Sciences, University of Birmingham , Edgbaston , Birmingham , UK.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Valsami-Jones
authors.affiliation: a Department of Biosciences , College of Life and Environmental Sciences, The Geoffrey Pope Building, University of Exeter , Exeter , UK .
authors.forename: Charles R
authors.initials: CR
authors.lastname: Tyler
authors.affiliation: a Department of Biosciences , College of Life and Environmental Sciences, The Geoffrey Pope Building, University of Exeter , Exeter , UK .
authors.forename: Tamara S
authors.initials: TS
authors.lastname: Galloway
mesh_terms: D033304:Amphipoda / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D001682:Biological Availability; D002563:Cerium / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D053960:DNA Breaks / Q000187:drug effects; D019015:Geologic Sediments; D015227:Lipid Peroxidation / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D046590:Spectroscopy, Electron Energy-Loss; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D002563:Cerium; C030583:ceric oxide; D013482:Superoxide Dismutase
keywords: Cerium oxide; Corophium volutator; nanotoxicology; oxidative stress