title: The effects of silver nanoparticles on fathead minnow  (Pimephales promelas) embryos.
abstract: Nanoparticles are being used in many commercial applications. We describe the toxicity of two commercial silver (Ag) nanoparticle (NP) products, NanoAmor and Sigma on Pimephales promelas embryos. Embryos were exposed to varying concentrations of either sonicated or stirred NP solutions for 96 h. LC(50) values for NanoAmor and Sigma Ag NPs were 9.4 and 10.6 mg/L for stirred and 1.25 and 1.36 mg/L for sonicated NPs, respectively. Uptake of Ag NPs into the embryos was observed after 24 h using Transmission Electron Microscopy and Ag NPs induced a concentration-dependent increase in larval abnormalities, mostly edema. Dissolved Ag released from Ag NPs was measured using Inductively Coupled-Mass Spectrometry and the effects tested were found to be three times less toxic when compared to Ag nitrate (AgNO(3)). The percentage of dissolved Ag released was inversely proportional to the concentration of Ag NPs with the lowest (0.625 mg/L) and highest (20 mg/L) concentrations tested releasing 3.7 and 0.45% dissolved Ag, respectively and percent release was similar regardless if concentrations were stirred or sonicated. Thus increased toxicity after sonication cannot be solely explained by dissolved Ag. We conclude that both dissolved and particulate forms of Ag elicited toxicity to fish embryos.
authors.affiliation: Department of Forestry & Natural Resources, Purdue University, 195 Marsteller St., West Lafayette, IN 47907, USA.
authors.forename: Geoff
authors.initials: G
authors.lastname: Laban
authors.forename: Loring F
authors.initials: LF
authors.lastname: Nies
authors.forename: Ronald F
authors.initials: RF
authors.lastname: Turco
authors.forename: John W
authors.initials: JW
authors.lastname: Bickham
authors.forename: Maria S
authors.initials: MS
authors.lastname: Sepúlveda
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003530:Cyprinidae / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000648:ultrastructure; D007928:Lethal Dose 50; D013058:Mass Spectrometry; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000633:toxicity*; D012834:Silver / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D012834:Silver