Practical and provocative, Bioavailability reviews prevalent understanding of the physical-chemical-biological mechanisms that control the bioavailability of both organic and inorganic contaminants in aquatic environments. Discusses the complex issues that surround many regulatory issues Emphasizes the need to identify and control that portion of the total concentration that is biologically available and can cause adverse effects, i.e., "active" Examines the influence of dynamic factors, such as pH, alkalinity, and light on these mechanisms Addresses the subject of speciation for both organic and inorganic contaminants