title: Properties of silver nanoparticles influencing their uptake in and toxicity to the earthworm Lumbricus rubellus following exposure in soil.
abstract: Physicochemical properties of nanoparticles influence their environmental fate and toxicity, and studies investigating this are vital for a holistic approach towards a comprehensive and adequate environmental risk assessment. In this study, we investigated the effects of size, surface coating (charge) of silver nanoparticles (AgNPs) - a most commonly-used nanoparticle-type, on the bioaccumulation in, and toxicity (survival, growth, cocoon production) to the earthworm Lumbricus rubellus. AgNPs were synthesized in three sizes: 20, 35 and 50 nm. Surface-coating with bovine serum albumin (AgNP_BSA), chitosan (AgNP_Chit), or polyvinylpyrrolidone (AgNP_PVP) produced negative, positive and neutral particles respectively. In a 28-day sub-chronic reproduction toxicity test, earthworms were exposed to these AgNPs in soil (0-250 mg Ag/kg soil DW). Earthworms were also exposed to AgNO3at concentrations below known EC50. Total Ag tissue concentration indicated uptake by earthworms was generally highest for the AgNP_BSA especially at the lower exposure concentration ranges, and seems to reach a plateau level between 50 and 100 mg Ag/kg soil DW. Reproduction was impaired at high concentrations of all AgNPs tested, with AgNP_BSA particles being the most toxic. The EC50for the 20 nm AgNP_BSA was 66.8 mg Ag/kg soil, with exposure to <60 mg Ag/kg soil already showing a decrease in the cocoon production. Thus, based on reproductive toxicity, the particles ranked: AgNP_BSA (negative) > AgNP_PVP (neutral) > Chitosan (positive). Size had an influence on uptake and toxicity of the AgNP_PVP, but not for AgNP_BSA nor AgNP_Chit. This study provides essential information on the role of physicochemical properties of AgNPs in influencing uptake by a terrestrial organism L. rubellus under environmentally relevant conditions. It also provides evidence of the influence of surface coating (charge) and the limited effect of size in the range of 20-50 nm, in driving uptake and toxicity of the AgNPs tested.
authors.affiliation: Division of Toxicology, Wageningen University and Research Centre, Tuinlaan 5, 6703 HE, Wageningen, The Netherlands; Alterra, Wageningen University and Research Centre, Droevendaalsesteeg 3, 6708 PB, Wageningen, The Netherlands. Electronic address: drsmakama@gmail.com.
authors.forename: Sunday
authors.initials: S
authors.lastname: Makama
authors.affiliation: Institut Català de Nanociència i Nanotecnologia (ICN2), Campus de la Universitat Autònoma de Barcelona (Campus UAB), 08193, Bellaterra, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Piella
authors.affiliation: RIKILT- Inst. of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB, Wageningen, The Netherlands.
authors.forename: Anna
authors.initials: A
authors.lastname: Undas
authors.affiliation: Alterra, Wageningen University and Research Centre, Droevendaalsesteeg 3, 6708 PB, Wageningen, The Netherlands.
authors.forename: Wim J
authors.initials: WJ
authors.lastname: Dimmers
authors.affiliation: RIKILT- Inst. of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB, Wageningen, The Netherlands.
authors.forename: Ruud
authors.initials: R
authors.lastname: Peters
authors.affiliation: Institut Català de Nanociència i Nanotecnologia (ICN2), Campus de la Universitat Autònoma de Barcelona (Campus UAB), 08193, Bellaterra, Barcelona, Spain; Vall d'Hebron Institut de Recerca (VHIR), Edificio Mediterránea, Hospital Vall d'Hebron, Passeig de la Vall d'Hebron, 119-129, 08035, Barcelona, Spain; Institut Català de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010, Barcelona, Spain.
authors.forename: Victor F
authors.initials: VF
authors.lastname: Puntes
authors.affiliation: Division of Toxicology, Wageningen University and Research Centre, Tuinlaan 5, 6703 HE, Wageningen, The Netherlands. Electronic address: nico.vandenbrink@wur.nl.
authors.forename: Nico W
authors.initials: NW
authors.lastname: van den Brink
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D048271:Chitosan / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004777:Environment; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D009835:Oligochaeta / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D010316:Particle Size; D011205:Povidone / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012834:Silver / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D013499:Surface Properties
chemical_list: D012989:Soil Pollutants; D012710:Serum Albumin, Bovine; D012834:Silver; D048271:Chitosan; D011205:Povidone
keywords: Cocoon production; Particle characterization; Soil organism; Surface coating; Toxicodynamics; Toxicokinetics