Bioassay procedures to describe, evaluate, and predict the potential hazard of toxic materials to organisms and ecosystems, and the health-related aspects of polluted waters continue to receive widespread attention. Symposium proceedings and books pertinent to toxic substances management and test procedures have appeared, as have several literature reviews pertinent to specific pollutants. The proceedings of the fifth annual ASTM symposium on aquatic toxicology presented a collection of papers directed to research needs in aquatic toxicology and hazard assessment, new concepts in aquatic toxicology, biological availability and sediment toxicity, and hazard assessment and water quality criteria.1 A state-of-the-art overview pertinent to modeling the fate of chemicals in the aquatic environment propounded the concept that hazard assessment requires understanding the relationships between chemical concentrations that cause adverse affects on aquatic life and environmental exposure.2 This book featured definitions of chemical, physical, and biological processes that determine chemical fate; modeling of physical and chemical fate processes, water quality, microbial transformation and bio degradation; and modeling as a tool in assessing chemical hazard. Cairns et al.3 provided methods, advantages, difficulties, and future possibilities of biological monitoring in water pollution condensed into six categories including: early-warning systems; receiving system functional methods, relationships, and indexes; receiving system methodology based on community structure; toxicity testing; preference and avoidance studies; and future needs within the field as a whole. Fundamentals of freshwater pollution and its effects on living organisms, including an account of the work of the water industry in pollution control, were presented in a new textbook.4 Specific pollutants toxic to aquatic organisms were reviewed including petroleum and specific petroleum hydrocarbons,5 copper,6 zinc,7 lead,8 cadmium,9 chlorine residuals,10 halogenated hydrocarbons,11 oil well drilling fluids,12 and acidic de position on aquatic ecosystems.13