This volume describes the theory and methods of environmental risk assessment, the use of environmental effect, fate and hazard information in risk management of chemicals and contaminated land, explains why an integrated assessment is needed both for the risk of chemicals and polluted sites. Efficient tools such as early warning and environmental monitoring with special sensors, or in situ measurements and decision making, modeling and mapping are discussed in details. A nanotechnology method, using the special molecule of cyclodextrin, is introduced as a versatile tool in environmental assessment and monitoring.