In the continuing fight against organic environmental xenobiotics, the initial success attributed to bioremediation has paled, in part due to the low availability of xenobiotics entrapped within a soil or sediment matrix. This has generated a very significant wave of interest in the bioavailability issue. However, much experimental evidence is puzzling or contradictory, mechanistic theories are embryonic, and implications for the practice of bioremediation or concerning the natural fate of xenobiotics are still tentative.
The debate in Europe and the USA is vigorous. Eastern Europe, following the liberalisation of the economy and political life, is evolving in a similar direction. In many cases, however, limited access to literature sources, severe language barriers, and the lack of a strong pluridisciplinary tradition are hampering the adoption of state of the art techniques.
Originally intended to allow scientists in East European countries to become acquainted with the key aspects of the bioavailability debate that is unfolding in the scientific literature in the West, and with its implications for bioremediation efforts, the present book presents a very complete coverage of the theoretical and practical aspects of the (limited) bioavailability of organic xenobiotics in the environment.

Zusammenfassung
Proceedings of the NATO Advanced Study Institute, held in Prague, Czech Republic from 18-29 August 1997

Inhalt
I. Organic Pollutants and Bioremediation.- Persistent Organic Contaminants in the Environment: PAHs as a Case Study.- Evaluation of Contamination Level of Dnieper River Basin by Organic and Inorganic Toxicants.- Underground Pollution at a Former Military Installation in Valciunai (Lithuania).- Application of a Biodegradation-Redox Model for Predicting Bioremediation Performance *.- Bioremediation of Environments Contaminated with Organic Xenobiotics: Putting Microbial Metabolism to Work: What happens with the Contaminant once it has reached the Cell Surface?.- Factors Controlling the Biodegradation of Chemicals in Soils.- II. Assessment of Bioavailability.- The Use of Laboratory Model Systems to Elucidate the Mechanisms of Bioavailability of Hydrophobic Organic Compounds.- Pollutant Aging Studies in Soils. Relevancy of Bench Scale Assessments to Field Conditions *.- Factors Affecting the Evaluation of Long-Term PCB Biodegradation in Soils by White Rot Fungi *.- Quantifying the Intrinsic Bioremediation Potential and the Hazard Index of Organic Xenobiotics in Aquifers Based on their Bioavailability Rates *.- The Use of Whole-Cell Living Biosensors to Determine the Bioavailability of Pollutants to Micoorganisms .- Abiotic Transformations of Organic Xenobiotics in Soils: A Compounding Factor in the Assessment of Bioavailability.- Evaluation of Soil Adsorption-Desorption Capacity for the Assessment of Pesticide Bioavailability.- Bioavailability of Organic Xenobiotics in the Environment: A Critical Perspective.- III. Processes that Control Bioavailability.- Physico-Chemical Characterization, Reactivity and Biodegradability of Soil-Organic Matter.- Organic Pollutants Associated with Macromolecular Soil Organic Matter and Natural Formation of Bound Residues.- Phase-Distributions of Hydrophobic Chemicals in the Aquatic Environment: Existing Portioning Models are Unable to Predict the Dissolved Component in Several Common Situations.- Bioavailability of Xenobiotic Organic Compounds to Remediate Soil Containing Clay Fractions: Limits of Engineering Solutions.- Effect of PAHs and Heavy Metals on Activity of Soil Microflora.- Transport of Organic Xenobiotics in the Environment.- IV. Strategies to Modify Bioavailability in Situ.- Limited Bioavailability of Organic Contaminants in the Environment: Policy Implications.- The Role of Plants in the Remediation of Contaminated Soils: Phytoremediation of Soils.- Reduction of the Bioavailability of PAHS in Heavily Contaminated Soils and Sediments Treated via a Physico-Chemical Process.- Surfactants-Enhanced Bioremediation: A Review of the Effects of Surfactants on the Bioavailability of Hydrophobic Organic Chemicals in Soils.