title: Comparing the effects of nanosilver size and coating variations on bioavailability, internalization, and elimination, using Lumbriculus variegatus.
abstract: As the production and applications of silver nanoparticles (AgNPs) increase, it is essential to characterize fate and effects in environmental systems. Nanosilver materials may settle from suspension; therefore, the authors' objective was to utilize environmentally relevant bioassays and study the impact, bioaccumulation, tissue distribution, uptake, and depuration of AgNPs on a sediment-dwelling invertebrate, Lumbriculus variegatus. Hydrodynamic diameters of uncoated 30-nm, 80-nm, and 1500-nm AgNP powders and a polyvinyl pyrrolidone (PVP) AgNP suspension were measured utilizing dynamic light scattering in freshwater media (0-280 µS/cm). Aggregation for 30 nm, 80 nm, and 1500 nm silver increased with conductivity but was minimal for PVP silver. Lumbriculus variegatus were exposed to AgNPs or silver nitrate (AgNO3 ) spiked into sediment (nominally 100 mg/kg) and water (PVP 30 nm and 70 nm Ag, nominally 5 mg/L). Uptake was assessed through inductively coupled plasma mass spectroscopy (ICP-MS) and hyperspectral imaging. Particle sizes were examined through field flow fractionation-ICP-MS (FFF-ICP-MS) and ICP-MS in single particle mode (SP-ICP-MS). Lumbriculus variegatus were also depurated for 6 h, 8 h, 24 h, and 48 h to determine gut clearance. Bioaccumulation factors of sediment-exposed L. variegatus were similar regardless of particle size or coatings. The FFF-ICP-MS and SP-ICP-MS detected AgNPs for up to 48 h post depuration. The present study provides information on bioaccumulation and interactions of AgNPs within biological systems.
authors.affiliation: Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS, USA. jessica.g.coleman@us.army.mil
authors.forename: Jessica G
authors.initials: JG
authors.lastname: Coleman
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Kennedy
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Bednar
authors.forename: James F
authors.initials: JF
authors.lastname: Ranville
authors.forename: Jennifer G
authors.initials: JG
authors.lastname: Laird
authors.forename: Ashley R
authors.initials: AR
authors.lastname: Harmon
authors.forename: Charolett A
authors.initials: CA
authors.lastname: Hayes
authors.forename: Evan P
authors.initials: EP
authors.lastname: Gray
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Higgins
authors.forename: Guilherme
authors.initials: G
authors.lastname: Lotufo
authors.forename: Jeffery A
authors.initials: JA
authors.lastname: Steevens
mesh_terms: D000818:Animals; D001682:Biological Availability; D005618:Fresh Water; D019015:Geologic Sediments / Q000737:chemistry; D053768:Metal Nanoparticles; D009835:Oligochaeta / Q000187:drug effects* / Q000378:metabolism; D010316:Particle Size; D011205:Povidone / Q000737:chemistry; D012834:Silver / Q000737:chemistry / Q000378:metabolism*; D012835:Silver Nitrate / Q000378:metabolism; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D012834:Silver; D012835:Silver Nitrate; D011205:Povidone
keywords: Aquatic; Bioavailability; Lumbriculus variegatus; Nanoparticles; Silver