title: Quantity and quality of natural organic matter influence the ecotoxicity of titanium dioxide nanoparticles.
abstract: Nanoparticles' fate is amongst other parameters determined by the quantity and quality of natural organic matter (NOM). Consequently, the ecotoxicity of nanoparticles is modified, while only little information is available on the NOM characteristics triggering this interplay. This study systematically examined how NOM quantity and quality influences the acute ecotoxicity of titanium dioxide nanoparticles (nTiO2) towards Daphnia magna. Therefore, two nTiO2products (A-100 and P25; ∼100 nm) were investigated in combination with seven NOM types of variable quality at four levels each (up to 4.00 mg total organic carbon/L). The results showed that - independent of the applied nTiO2product and NOM type - nTiO2ecotoxicity decreased up to a factor of >18 with increasing NOM concentration. More importantly, increasing levels of aromaticity and hydrophobicity of the NOM decreased the magnitude of toxic effects caused by nTiO2, which was again independent of the nTiO2product tested. In the light of the ubiquitary presence of NOM, the ecotoxicological risk of nTiO2in surface waters with high NOM loads is likely moderate. However, interactions of nTiO2and NOM in combination with other natural or chemical stressors are not well-understood but seem to be fundamental for a reliable risk assessment of nanoparticles.
authors: a Institute for Environmental Sciences, University of Koblenz-Landau , Landau , Germany.|b nEcoTox Consult , Schifferstadt , Germany , and.
authors: Frank
authors: F
authors: Seitz
authors: a Institute for Environmental Sciences, University of Koblenz-Landau , Landau , Germany.|b nEcoTox Consult , Schifferstadt , Germany , and.
authors: Ricki R
authors: RR
authors: Rosenfeldt
authors: a Institute for Environmental Sciences, University of Koblenz-Landau , Landau , Germany.
authors: Marie
authors: M
authors: Müller
authors: a Institute for Environmental Sciences, University of Koblenz-Landau , Landau , Germany.
authors: Simon
authors: S
authors: Lüderwald
authors: a Institute for Environmental Sciences, University of Koblenz-Landau , Landau , Germany.
authors: Ralf
authors: R
authors: Schulz
authors: a Institute for Environmental Sciences, University of Koblenz-Landau , Landau , Germany.|c Department of Aquatic Sciences and Assessment , Swedish University of Agricultural, Sciences , Uppsala , Sweden.
authors: Mirco
authors: M
authors: Bundschuh
mesh_terms: D000818:Animals; D003621:Daphnia / Q000187:drug effects*; D054750:Ecotoxicology / Q000379:methods*; D006812:Humic Substances / Q000032:analysis*; D053758:Nanoparticles / Q000633:toxicity*; D014025:Titanium / Q000633:toxicity*; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D006812:Humic Substances; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium
keywords: Crustacea; SUVA; Suwannee River; dissolved organic matter; toxicity mitigation