Environmental fate and effect of engineered nanoparticles: state of the art and research need for risk assessment.

The increasing use of engineered nanoparticles (ENP) in various applications will likely lead to their release into the environment. Assessing the environmental risk posed by these ENP requires an understanding of their environmental behaviour and ecotoxicity. In this review, the state of knowledge on the possible environmental sources and fate of ENP, and potential ecotixocological effects, is presented. ENP features relevant to their environmental behaviour are identified and discussed, as well as the specific processes of NPs in the environment (e.g. aggregation, stability, and possible interaction with contaminants). Although preliminary results from ecotoxicological studies show that physicochemical properties of ENP play an important role with respect to their potential hazard, much less is known how these properties affect the behaviour and reactivity of NPs in the environment, and how these features may be used to develop preliminary hazard or risk analysis or to provide a basis for effective risk management approaches