The utilization of nanoparticles is still increasing, which is accompanied by their (accidental) release into environments, where they pose a potential risk for e.g. aquatic ecosystems. However, their implications in the welfare of human and wildlife are largely unknown. Titanium dioxide nanoparticles (nTiO2), in particular, are frequently used as ingredients in consumer products. Studies that investigated the impact of nTiO2 on aquatic organisms indicated inconsistent toxicities. This may be explained by different products and preparation procedures applied to obtain nanoparticle suspensions, which may also translate into different nanoparticle characteristics.

Therefore, this project aims at understanding the importance of nanoparticle characteristics for their impact on aquatic macroinvertebrates under varying environmental scenarios relevant for floodplain conditions. Hence, IMPACT contributes particularly to the following main questions:

What are the mechanisms causing biological impact?
To which extent is the biological impact influenced by the original nanoparticle characteristics and its aging status?
For this purpose nTiO2 will be used as model nanoparticles, and Daphnia magna as model organism. The identified mechanisms of toxicity will be investigated for their general applicability using other nanoparticles as well as a further Crustacean species, namely Gammarus fossarum.