Cerium oxide nanoparticles induce oxidative stress in the sediment-dwelling amphipod Corophium volutator
Taylor & Francis
Reason for embargo
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.
This study was supported by grants from EPSRC EP/G043140/1, DEFRA LK0852 and EU FP7-262163 to TSG and CRT. The use of FENAC was supported by NERC access grant 2011/05/002. We acknowledge funding from NERC (NE/H013148/1) and the Centre for Environmental Nanoscience and Risk.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.
Published online: 10 Nov 2015
Vol. 10, pp. 480 - 487
Place of publication