Photocatalytic properties of titanium dioxide nanoparticles affect habitat selection of and food quality for a key species in the leaf litter decomposition process

Feckler, Alexander; Rosenfeldt, Ricki R.; Seitz, Frank; Schulz, Ralf; Bundschuh, Mirco

Photocatalytic properties of titanium dioxide nanoparticles affect habitat selection of and food quality for a key species in the leaf litter decomposition process

2015

Feckler, Alexander | Rosenfeldt, Ricki R. | Seitz, Frank | Schulz, Ralf | Bundschuh, Mirco

Interactions with environmental parameters may alter the ecotoxicity of nanoparticles. The present study therefore assessed the (in)direct effects of nanoparticulate titanium dioxide (nano-TiO2) towards Gammarus fossarum, considering nano-TiO2's photocatalytic properties at ambient UV-intensities. Gammarids' habitat selection was investigated using its feeding preference on leaf discs either exposed to or protected from UV-irradiation in presence of nano-TiO2 as proxy (n = 49). UV-irradiation alone induced a significant preference for UV-protected habitats, which was more pronounced in simultaneous presence of nano-TiO2. This behaviour may be mainly explained by the UV-induced formation of reactive oxygen species (ROS) by nano-TiO2. Besides their direct toxicity, ROS may have lowered the leaf-quality in UV-exposed areas contributing (approximately 30%) to the observed behavioural pattern. Since the predicted no effect concentration of nano-TiO2 in combination with UV-irradiation falls below the predicted environmental concentration this study underpins the importance of considering environmental parameters during the risk assessment of nanoparticles.

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