Source tracking (contact Anders Baun)
While environmental exposure to engineered nanomaterials may be low today, the rapid increase in the number of construction materials and commodities containing nanomaterials will result in an increased dispersal in the urban environment and in the discharges to the environment. It is thus important to identify the sources and estimate the flows through the society in order to assess risks, to choose suitable mitigation options and to communicate with stakeholders. Procedures are developed for estimating environmental exposures to nanomaterials with the aim of coupling these to screening and ranking procedures to pinpoint potentially hazardous nanomaterials. The procedures are based on inherent properties of nanomaterials, well-known and established principles for substance and material flow analysis and new approaches for source tracking such as database mining and questionnaires as well as principles for forensic source tracking.
Ecotoxicity of nanomaterials (contact Anders Baun and K. Ole Kusk)
The ecotoxicological and other effects of nanomaterials on aquatic organisms are investigated for hazard identification and comparisons of toxicity. Results are aimed at filling data gaps in our current knowledge on environmental effects of nanomaterials with a strong focus of method evaluation and development. Our main focus is on non-vertebrate organisms like unicellular green algae and crustaceans, but our studies also cover other organisms like bacteria, sediment-dwelling invertebrates, aquatic plants and willow trees.
Nanoparticles as contaminant carriers (contact Anders Baun and Nanna Hartmann)
The study of possible interactions between nanoparticles and environmental contaminants is one of the major focal points of the group. These studies are carried out to establish if the presence of nanoparticles in non-toxic concentrations influence the effects and/or bioaccumulation of individual chemicals and/or chemical mixtures. The outcome of interaction (increase/decrease in effect/bioaccumulation) depends among other processes upon sorption of chemical to nanoparticles resulting in altered bioavailability of the sorbed chemical. Mixtures of nanoparticles as well as nanoparticles-chemicals are studied to analyze whether interaction occurs in the aquatic environment referring to a scenario where one substance affects the biological site of another (antagonism/synergism), and mixture studies enable quantitative analyses of the combined action of similarly and dissimilarly acting compounds.
Bioaccumulation in aquatic organisms (contact Anders Baun and K. Ole Kusk)
While the present environmental exposure concentrations to engineered nanomaterials may be low, the long term exposure and effect will depend on the bioaccumulation behaviour of the nanomaterials. Therefore, uptake and excretion of nanoparticles in aquatic organisms like algae and daphnids is investigated to obtain an insight in the processes and factors determining bioaccumulation levels and potential biomagnification in the food chain.