Aquatic environments, particularly sediments, can be important final sinks for engineered nanoparticles (ENPs), with benthic biota being potentially exposed. There is an increasing need for hazard data to improve the environmental risk assessment of ENPs regarding aquatic systems. The aim of this study was to determine the toxicokinetics of several pristine (as manufactured) Ag-NPs, Ag2S-NPs (used to simulate environmental aging of silver nanoparticles) and AgNO3 as the ionic counterpart, in the freshwater snail Physa acuta. Snails were exposed through 1) contaminated water (without sediment), 2) contaminated water and clean sediment, and 3) contaminated sediment. Bioavailability of Ag to the snails was greatly influenced by Ag characteristics, as different uptake and elimination kinetics were found for the different Ag forms within the same exposure route. Snails exposed via water revealed, in general, similar uptake kinetics, differing from exposure via contaminated sediment, suggesting that exposure route also had a determining role in Ag bioavailability. The simulated aged form (Ag2S-NPs) revealed fast uptake and depuration in snails from all experiments. When considering the double exposure route, which provides a more realistic contamination scenario, water was the main route, except for Ag2S-NPs, for which sediment was more important. The remarkably low elimination and high stored fraction of Ag in some exposures emphasizes the bioaccumulation ability of P. acuta and may raise concerns about possible trophic transfer. Snail shells accumulated low amounts of Ag. The present study highlights the need for a proper examination of the overall exposure scenario of Ag-NPs to benthic organisms. Our results contribute to the environmental risk assessment of Ag-NPs in benthic environments. This journal is
Bibliographical noteFunding Information:
This work was supported by the project NanoFASE (Nanomaterial Fate and Speciation in the Environment), financed by the European Union's Horizon 2020 research and innovation programme under grant agreement no 646002, and through a doctoral grant PVS (SFRH/BD/52571/2014) by FCT – Fundação para a Ciência e a Tecnologia. Thanks are due to FCT/MCTES for the financial support to CESAM (UIDP/ 50017/2020+UIDB/50017/2020), through national funds. AGP acknowledges support from the H2020 EU research infrastructure for nanosafety project NanoCommons (Grant Agreement No. 731032) and the POST-DOC/0718/0070 project, co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research and Innovation Foundation. SFG was funded by the project WE-NEED – WatEr NEEDs, Availability, Quality and Sustainability (WATERJPI/0008/2014) through a grant (BI/UI88/4957/2017), financed by the EU research programme Water Joint Programming Initiative 2015 Joint Call WaterWorks2014.
© 2020 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Materials Science (miscellaneous)
- Environmental Science(all)