title: Impact of sulfidation on the bioavailability and toxicity of silver  nanoparticles to Caenorhabditis elegans.
abstract: Sulfidation is a major transformation product for manufactured silver nanoparticles (Ag-MNPs) in the wastewater treatment process.We studied the dissolution, uptake, and toxicity of Ag-MNP and sulfidized Ag-MNPs (sAg-MNPs) to a model soil organism, Caenorhabditis elegans. Our results show that reproduction was the most sensitive endpoint tested for both Ag-MNPs and sAg-MNPs. We also demonstrate that sulfidation not only decreases solubility of Ag-MNP, but also reduces the bioavailability of intact sAg-MNP. The relative contribution of released Ag(+) compared to intact particles to toxicity was concentration dependent. At lower total Ag concentration, a greater proportion of the toxicity could be explained by dissolved Ag, whereas at higher total Ag concentration, the toxicity appeared to be dominated by particle specific effects.
authors.affiliation: Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Starnes
authors.forename: Jason M
authors.initials: JM
authors.lastname: Unrine
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Starnes
authors.forename: Blanche E
authors.initials: BE
authors.lastname: Collin
authors.forename: Emily K
authors.initials: EK
authors.lastname: Oostveen
authors.forename: Rui
authors.initials: R
authors.lastname: Ma
authors.forename: Gregory V
authors.initials: GV
authors.lastname: Lowry
authors.forename: Paul M
authors.initials: PM
authors.lastname: Bertsch
authors.forename: Olga V
authors.initials: OV
authors.lastname: Tsyusko
mesh_terms: D000818:Animals; D001682:Biological Availability; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000378:metabolism; D053768:Metal Nanoparticles / Q000032:analysis / Q000633:toxicity*; D053758:Nanoparticles; D012834:Silver / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D012987:Soil; D012995:Solubility; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D012834:Silver; D012987:Soil; D062065:Wastewater; D014874:Water Pollutants, Chemical