Contaminated bottom sediments and their negative impacts on water quality are a major problem in surface waters throughout the United States as well as in many other parts of the world. Even after elimination of the primary contaminant sources, these bottom sediments will be a main source of contaminants for many years to come. In order to determin

Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.

This is the first interdisciplinary book on the mobilization of nutrients and pollutants in the water phase due to hydrodynamic processes. Coverage includes the formation of aggregates in turbulent water; flocks and biofilms from organic reactions; and the formation of new surfaces for re-adsorption of dissolved pollutants. The book gathers papers resulting from an International Symposium on Sediment Dynamics and Pollutant Mobility in River Basins in Hamburg, Germany, March, 2006.