Influence of Humic Acid on Titanium Dioxide Nanoparticle Toxicity to Developing Zebrafish

TitleInfluence of Humic Acid on Titanium Dioxide Nanoparticle Toxicity to Developing Zebrafish
Publication TypeJournal Article
Year of Publication2013
AuthorsYang, SP, Bar-Ilan, O, Peterson, RE, Heideman, W, Hamers, RJ, Pedersen, JA
JournalEnvironmental Science & Technology
Volume47
Pagination4718-4725
Abstract

Titanium dioxide nanoparticle (TiO2NP) suspension stability can be altered by adsorption of dissolved organic matter (DOM). This is expected to impact their environmental fate and bioavailabllity. To date, the influence of DOM on the toxicity of TiO(2)NPs to aquatic vertebrates has not been reported. We examined the impact of Suwannee River humic acid (HA) on the toxicity of TiO(2)NPs to developing zebrafish (Danio rerio) in the dark and under simulated sunlight illumination. Adsorption of HA increased suspension stability and decreased TiO2NP exposure. TiO(2)NPs were more toxic in the presence of HA. In the absence of simulated sunlight, a small but significant increase in lethality was observed in fish exposed to TiO(2)NPs in the presence of HA. Under simulated sunlight illumination, photocatalytic degradation of HA reduced suspension stability. Despite the lower concentrations of Ti associated with fish in the treatments containing HA, under simulated sunlight illumination, median lethal concentrations were lower and oxidative DNA damage was elevated relative to fish exposed to TiO(2)NPs in the absence of HA. This study demonstrates the importance of considering environmental factors (i.e., exposure to sunlight, adsorption of DOM) when assessing the potential risks posed by engineered nanomaterials in the environment.