Fate and Effects of Nanoparticles in the Environment and New Approaches for Their Risk Assessment

Considering the needs for the Environmental Risk Assessment (ERA) of Engineered Nanoparticles (ENPs), the main aim of this PhD study is to propose an ERA approach for ENPs that enables evaluating all representative factors for the risk, provides tools for reducing uncertainties and points out further research needs and risk management strategies with quantitative risk communication. Silver nanoparticles (AgNPs) and TiO2 NP were chosen as model ENPs due to their common usage in consumer products. Two different AgNPs, with citrate and PVP coating, were used to compare the effects of coating material. In the context of this main aim, the following objectives were studied to generate data or knowledge for the proposed ERA: 1) to determine in a systematic manner the most relevant water chemistry parameters for the agglomeration of model ENPs, which is the key fate process for the fate of ENPs 2) to classify the aquatic environment based on the relevant water chemistry parameters for agglomeration by considering the possible temporal changes according to the results of ENP agglomeration behavior in natural water samples 3) to evaluate the toxicokinetics and toxicodynamics of AgNPs in E. crypticus by investigating the relation between uptake and effects and 4) to determine the survival and reproductive toxicity of AgNPs to E. crypticus and the relation between toxicity and soil organic matter content and pH of the soil.