Invited Paper AS+NS-TuA7
Behavior of Engineered Nanoparticles in Aquatic Environments – An Overview

Tuesday, November 10, 2009, 4:00 pm, Room C2

The behavior of engineered nanoparticles in aquatic systems will be influenced by three main factors: the physiochemical conditions encountered in a specific environment; the nanoparticles' bioavailability; and any transformation that may occur during biological uptake and excretion. Physiological conditions, such as the type and concentration of organic matter and inorganic species, will dictate aggregation kinetics. Environments that encourage nanoparticle stability may increase their persistence in the water column while those that favor instability may result in nanoparticle deposition among bottom sediments. Nanoparticle bioavailability will be dictated by both spatial and phase distribution; large nanoparticle aggregates bound to sediment material may be less available to aquatic organisms than, for example, single nanoparticles remaining in solution. Biological ingestion and subsequent excretion may result in nanoparticle degradation and/or changes to aggregation behavior. The objective of this presentation is to provide an overview of these three factors as they apply to the fate, transport, and bioavailability of engineered nanoparticles. Information gained from studying naturally-formed nanoparticles (colloids) will be reviewed and case studies will illustrate our current knowledge of engineered nanoparticle behavior.