Background:Nanoparticles are usually defined as material with at least one dimension between 1 nm and 100 nm.Manufactured nanoparticles (NPs) show great technical promise, but little is known about their effects onliving systems. NPs exhibit special physico-chemical properties and reactivities due to their small sizeand homogenous composition, which are not present at the larger scale. Depending on their use, NPs willpotentially pollute subsurface aquifers, surface lakes and rivers. This contamination may affect aquaticorganisms and environmental health as NPs may enter the food chain. Recently, critical questions havebeen raised regarding the impact of manufactured NPs on the environment, their interaction with otherpollutants (such as metals and organic compounds) and with human health. NPs are a very importantgroup of emerging compounds. Some NPs are known to be incorporated in living organisms followed bybinding and deformation of DNA, impact crustacean population and food web dynamics, and to induceoxidative radicals and changing gene expression patterns in exposed tissues. All this can potentiallycounteract the sustainable use of water bodies for drinking water, recreation and adding an additionalstress to the aquatic environment.Objectives:The aim of NanEAU is to adapt and develop test protocols for the evaluation of (environmental) toxicityof emerging NPs alone or in combination with more common contaminants. In addition to classicalassays using established biomarkers and standardized procedures, novel predicting biomarkers applyingproteomic and genomic approaches will be developed. The possibility of uptake from the water in highervertebrates and intracellular localization will be studied.Applied Methods: NPs will be selected in close cooperation with the ongoing FP7 project NANOTEST(see appendix II) to make best use of the expertise available in this project.Within NanEAU a miniaturized version of the Microtox-Assay® (mMicrotox-Assay®) will be applied tostudy effects of NPs alone and the modulating interaction of NPs in co-incubation with selected classes ofcontaminants (Hg, PCBs, etc.) on the light production of a bacterium (Vibrio fischeri).Different classes of aquatic organisms (algae, crustaceans) will be evaluated for their potential use asrelevant test systems for NPs applying available standardized test protocols for algae (OECD 201 biotest)or for Daphnias (OECD Guideline 202). Relevant combinations (NPs, contaminants) depending onresults from the mMicrotox-Assay® will be tested for the correlation with mMicrotox-Assay® results totest its predictive value.Two model systems to study uptake of NPs from water, namely a relevant in-vivo fish model (Daniorerio) and a relevant in-vitro model for the intestine of humans (Caco-2 in co-culture with HT29-MTXmucus-secreting cells) will be applied to study NP uptake (applying nano-secondary ion massspectrometry – NanoSIMS), the effects on NP influenced pathways (apoptosis, oxidative stress, etc.) andeffects on the proteome/transcriptome to search for new predictive biomarkers.Expected outcomes: The expected outcome of NanEAU is additional information on behaviour andinteraction of NPs in the water, its potential risks for a range of organisms, and new biomarkers for thepresence and effects of NPs supporting the sustainable use of water resources.