Approaches to the Assessment of the Environmental Fate of Chemical Contaminants: Introduction. Predictive Approaches and Models. The Role of Physiocochemical Properties. Evaluative Models. The Role of Field Studies. References. Environmental Toxicology: Introduction. Classic Toxicology. Toxicology of Mixtures. Field Studies: Biological Monitoring and Nondestructive Biomarkers. Predictive Tools in Environmental Toxicology (SARs). The Need for the Evaluation of Ecosystem Responses. References. Hazard Evaluation and Risk Assessment: Introduction. Environmental Fate Assessment. Hazard and Risk Characterization. The Ecotoxicological Approach. An Example of Application: Semivolatile Organochlorinated Hydrocarbons (SOCs) in the Mediterranean Sea: Sources, Fate and Hazard Assessment. Uncertainty of Present Approaches: Future Research Needs. Conclusions. References. Index.