title: Soil pH effects on the comparative toxicity of dissolved zinc, non-nano and nano ZnO to the earthworm Eisenia fetida.
abstract: To determine how soil properties influence nanoparticle (NP) fate, bioavailability and toxicity, this study compared the toxicity of nano zinc oxide (ZnO NPs), non-nano ZnO and ionic ZnCl2 to the earthworm Eisenia fetida in a natural soil at three pH levels. NP characterisation indicated that reaction with the soil media greatly controls ZnO properties. Three main conclusions were drawn. First that Zn toxicity, especially for reproduction, was influenced by pH for all Zn forms. This can be linked to the influence of pH on Zn dissolution. Secondly, that ZnO fate, toxicity and bioaccumulation were similar (including relationships with pH) for both ZnO forms, indicating the absence of NP-specific effects. Finally, earthworm Zn concentrations were higher in worms exposed to ZnO compared to ZnCl2, despite the greater toxicity of the ionic form. This observation suggests the importance of considering the relationship between uptake and toxicity in nanotoxicology studies.
authors.affiliation: Department of Basic Science and Environment, University of Copenhagen , Thorvaldsensvej 40, 1871 Frederiksberg , Denmark.
authors.forename: Laura R
authors.initials: LR
authors.lastname: Heggelund
authors.forename: Maria
authors.initials: M
authors.lastname: Diez-Ortiz
authors.forename: Stephen
authors.initials: S
authors.lastname: Lofts
authors.forename: Elma
authors.initials: E
authors.lastname: Lahive
authors.forename: Kerstin
authors.initials: K
authors.lastname: Jurkschat
authors.forename: Jacek
authors.initials: J
authors.lastname: Wojnarowicz
authors.forename: Nina
authors.initials: N
authors.lastname: Cedergreen
authors.forename: David
authors.initials: D
authors.lastname: Spurgeon
authors.forename: Claus
authors.initials: C
authors.lastname: Svendsen
mesh_terms: D000818:Animals; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D009835:Oligochaeta / Q000737:chemistry* / Q000187:drug effects; D012098:Reproduction / Q000187:drug effects; D012987:Soil / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D015032:Zinc / Q000737:chemistry / Q000633:toxicity*; D015034:Zinc Oxide / Q000737:chemistry / Q000633:toxicity*
chemical_list: D012987:Soil; D014867:Water; D015032:Zinc; D015034:Zinc Oxide