Bioaccumulation, subcellular distribution and toxicity of sediment-associated copper in the ragworm Nereis diversicolor: The relative importance of aqueous copper, copper oxide nanoparticles and microparticles

The sediment-dwelling ragworm, Nereis diversicolor was exposed to sediment spiked with aqueous Cu (Cu-Aq, CuCl2), CuO nanoparticles (CuONP) or CuO microparticles (CUOMICRO) at 150 mu g Cu g(-1) dw sediment for 10d. Exposures to Cu-Aq and CuOMICRO caused mortality (62.5 and 37.5%, respectively), whereas mean burrowing time increased during exposure to Cu-Aq and CuONP from 0.12 h (controls) to 19.3 and 12.2 h, respectively. All Cu treatments bioaccumulated, especially Cu-Aq (up to 4 times more than the other treatments). Cu was roughly equally distributed among the five subcellular fractions in controls and worms exposed to CuONP or CuOMICRO. In contrast, approximate to 50% of accumulated Cu in Cu-Aq exposed worms was found in metal rich granules and significantly more Cu was present in heat-denatured proteins and organelles than in worms exposed to CuOMICRO or in controls. Our results suggest that Cu form affects its bioaccumulation and subsequent toxicity and detoxification in a polychaete like N. diversicolor. (C) 2015 Elsevier Ltd. All rights reserved.