Bioaccumulation and effects of different‐shaped copper oxide nanoparticles in the deposit‐feeding snail Potamopyrgus antipodarum
Copper oxide (CuO) nanoparticles (NP) are among the most widely used engineered NPs, and thus likely to end up in the environment, predominantly in sediments. CuO NPs have been found to be toxic towards a variety of (mainly pelagic) organisms, but to differing degrees. In the present study, the influence of CuO NP shape on bioavailability and toxicity in the sediment‐dwelling freshwater gastropod Potamopyrgus antipodarum was examined. In two separate studies snails were exposed to either clean sediment or sediment spiked with either aqueous Cu or CuO NPs of different shape (rods, spheres, platelets) at 240 μg Cu/g dry weight of sediment (nominal). In neither of the studies was survival found to be related to Cu form (i.e., free ion versus particle) or shape, whereas snail growth was severely influenced by both form and shape. Reproduction was only affected (by CuO NP spheres and aqueous Cu) when estimated as the total number (live plus dead) of juveniles produced per snail per week. Both the aqueous and particulate forms of Cu were available for uptake by snails when mixed into sediment. However, Cu body‐burden was not directly related to observed effects. The present study stresses that 1) better understanding of uptake mechanisms and internal distribution pathways of NPs, and that 2) assessment of long‐term consequences of NP exposure are both needed.