title: Short-term soil bioassays may not reveal the full toxicity potential for nanomaterials; bioavailability and toxicity of silver ions (AgNO₃) and silver nanoparticles to earthworm Eisenia fetida in long-term aged soils.
abstract: This study investigated if standard risk assessment hazard tests are long enough to adequately provide the worst case exposure for nanomaterials. This study therefore determined the comparative effects of the aging on the bioavailability and toxicity to earthworms of soils dosed with silver ions and silver nanoparticles (Ag NP) for 1, 9, 30 & 52 weeks, and related this to the total Ag in the soil, Ag in soil pore water and earthworm tissue Ag concentrations. For ionic Ag, a classical pattern of reduced bioavailability and toxicity with time aged in the soil was observed. For the Ag NP, toxicity increased with time apparently driven by Ag ion dissolution from the added Ag NPs. Internal Ag in the earthworms did not always explain toxicity and suggested the presence of an internalised, low-toxicity Ag fraction (as intact or transformed NPs) after shorter aging times. Our results indicate that short-term exposures, without long-term soil aging, are not able to properly assess the environmental risk of Ag NPs and that ultimately, with aging time, Ag ion and Ag NP effect will merge to a common value.
authors.affiliation: Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, UK. Electronic address: mdiez@leitat.org.
authors.forename: Maria
authors.initials: M
authors.lastname: Diez-Ortiz
authors.affiliation: Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, UK.
authors.forename: Elma
authors.initials: E
authors.lastname: Lahive
authors.affiliation: Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, UK.
authors.forename: Suzanne
authors.initials: S
authors.lastname: George
authors.affiliation: Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, UK; Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
authors.forename: Anneke
authors.initials: A
authors.lastname: Ter Schure
authors.affiliation: Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
authors.forename: Cornelis A M
authors.initials: CAM
authors.lastname: Van Gestel
authors.affiliation: Department of Materials, Oxford University, Begbroke Science Park, Sandy Lane, Yarnton, Oxford OX5 1PF, UK.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Jurkschat
authors.affiliation: Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, UK.
authors.forename: Claus
authors.initials: C
authors.lastname: Svendsen
authors.affiliation: Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Spurgeon
mesh_terms: D000818:Animals; D001681:Biological Assay; D001682:Biological Availability; D053768:Metal Nanoparticles / Q000633:toxicity*; D009835:Oligochaeta / Q000187:drug effects*; D018570:Risk Assessment; D012834:Silver / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D013997:Time Factors; D014867:Water
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014867:Water; D012834:Silver
keywords: Aging; Bioavailability; Dissolution; Earthworm; Silver nanoparticles