title: Influence of hardness on the bioavailability of silver to a freshwater snail after waterborne exposure to silver nitrate and silver nanoparticles.
abstract: The release of Ag nanoparticles (AgNPs) into the aquatic environment is likely, but the influence of water chemistry on their impacts and fate remains unclear. Here, we characterize the bioavailability of Ag from AgNO(3) and from AgNPs capped with polyvinylpyrrolidone (PVP AgNP) and thiolated polyethylene glycol (PEG AgNP) in the freshwater snail, Lymnaea stagnalis, after short waterborne exposures. Results showed that water hardness, AgNP capping agents, and metal speciation affected the uptake rate of Ag from AgNPs. Comparison of the results from organisms of similar weight showed that water hardness affected the uptake of Ag from AgNPs, but not that from AgNO(3). Transformation (dissolution and aggregation) of the AgNPs was also influenced by water hardness and the capping agent. Bioavailability of Ag from AgNPs was, in turn, correlated to these physical changes. Water hardness increased the aggregation of AgNPs, especially for PEG AgNPs, reducing the bioavailability of Ag from PEG AgNPs to a greater degree than from PVP AgNPs. Higher dissolved Ag concentrations were measured for the PVP AgNPs (15%) compared to PEG AgNPs (3%) in moderately hard water, enhancing Ag bioavailability of the former. Multiple drivers of bioavailability yielded differences in Ag influx between very hard and deionized water where the uptake rate constants (k(uw), l g(-1) d(-1) ± SE) varied from 3.1 ± 0.7 to 0.2 ± 0.01 for PEG AgNPs and from 2.3 ± 0.02 to 1.3 ± 0.01 for PVP AgNPs. Modeling bioavailability of Ag from NPs revealed that Ag influx into L. stagnalis comprised uptake from the NPs themselves and from newly dissolved Ag.
authors: a John Muir Institute of the Environment, University of California , Davis , CA , USA .
authors: Tasha
authors: T
authors: Stoiber
authors: b US Geological Survey , Menlo Park , CA , USA .
authors: Marie-Noële
authors: MN
authors: Croteau
authors: c School of Geography, Earth and Environmental Sciences, University of Birmingham , Edgbaston , Birmingham , UK .
authors: Isabella
authors: I
authors: Römer
authors: c School of Geography, Earth and Environmental Sciences, University of Birmingham , Edgbaston , Birmingham , UK .|d School of Public Health, University of Indonesia, Kampus Baru UI Depok , Jawa Barat , Indonesia , and.
authors: Mila
authors: M
authors: Tejamaya
authors: c School of Geography, Earth and Environmental Sciences, University of Birmingham , Edgbaston , Birmingham , UK .|e Center for Environmental Nanoscience and Risk, University of South Carolina , Columbia , SC , USA.
authors: Jamie R
authors: JR
authors: Lead
authors: a John Muir Institute of the Environment, University of California , Davis , CA , USA .|b US Geological Survey , Menlo Park , CA , USA .
authors: Samuel N
authors: SN
authors: Luoma
mesh_terms: D000818:Animals; D001682:Biological Availability; D002413:Cations, Divalent / Q000737:chemistry / Q000493:pharmacokinetics; D005618:Fresh Water; D006244:Hardness; D008195:Lymnaea / Q000187:drug effects / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011205:Povidone / Q000737:chemistry; D012834:Silver / Q000737:chemistry* / Q000493:pharmacokinetics*; D012835:Silver Nitrate / Q000737:chemistry* / Q000493:pharmacokinetics*; D014867:Water; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D002413:Cations, Divalent; D014874:Water Pollutants, Chemical; D014867:Water; D012834:Silver; D011092:Polyethylene Glycols; D012835:Silver Nitrate; D011205:Povidone
keywords: Bioaccumulation; Lymnaea stagnalis; hardness; modeling; nanoparticles; silver