title: Ecotoxicological assessment of silica and polystyrene nanoparticles assessed by a multitrophic test battery.
abstract: The acute ecotoxicity of different diameters of silica and polyethyleneimine polystyrene (PS-PEI) nanoparticles (NPs) was assessed on a test battery of aquatic organisms representing different trophic levels. Daphnia magna, Thamnocephalus platyurus, Pseudokirchneriella subcapitata and Vibrio fischeri, were employed in a series of standard acute ecotoxicity tests and work was complemented with two cytotoxicological end points on a rainbow trout gonadal cell line (RTG-2). Physico-chemical characterization of the NPs was performed in the different test media employed, using dynamic light scattering (DLS) and zeta potentiometry. In contrast to silica NPs exposure, for which no effect was observed for concentrations up to 1000 μg ml(-1) for all in vivo aquatic organisms tested, significant toxicity was detected after exposure to PS-PEI NPs at concentrations from 0.40 μg ml(-1) to 416.5 μg ml(-1). Differing sensitivities for each NP diameter for the different organisms were observed as: P. subcapitata≥D. magna>T. platyurus>V. fischeri. The effects observed were dependent in some cases on the NP size, a higher effect being observed for the larger NPs. Finally, cytotoxicity studies showed an effect at the highest concentrations for both sets of NPs which was greater in the case of the PS-PEI NPs. However, as agglomeration and sedimentation of the nanoparticles was observed at these concentrations, the cytotoxicity studies were found not to be a reliable ecotoxicity test model.
authors.affiliation: Radiation and Environmental Science Centre, Focas Research Institute, Dublin Institute of Technology, Dublin 8, Ireland. maria.casado@mydit.ie
authors.forename: Maria P
authors.initials: MP
authors.lastname: Casado
authors.forename: Ailbhe
authors.initials: A
authors.lastname: Macken
authors.forename: Hugh J
authors.initials: HJ
authors.lastname: Byrne
mesh_terms: D048908:Aliivibrio fischeri; D000818:Animals; D033202:Anostraca / Q000187:drug effects; D059001:Aquatic Organisms; D000460:Chlorophyta; D003621:Daphnia / Q000187:drug effects; D054750:Ecotoxicology; D020387:Food Chain; D006801:Humans; D053758:Nanoparticles / Q000633:toxicity*; D017686:Oncorhynchus mykiss; D011137:Polystyrenes / Q000633:toxicity*; D018570:Risk Assessment; D012822:Silicon Dioxide / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D011137:Polystyrenes; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide