In 2002, the Swedish Metal Information Task Force (MITF) engaged the Environmental Research Group (MFG) to update previous monographs on copper, zinc and major alloying metals (such as chromium, nickel and molybdenum) in society and in the environment. This book presents new results on metal fluxes from society to the environment, on metal speciation in water, soil and sediment, and its interpretation in terms of mobility, biological uptake and toxicity. The scientific fundamentals of new approaches, like the Acid Volatile Sulphide (AVS) concept to predict metal bioavailability in sediments, and the Biotic Ligand Model (BLM) to calculate the toxicity of metals to aquatic organisms, are critically evaluated, with a focus on copper, nickel, zinc, and, in part, chromium.

Recent scientific advances now offer an improved understanding of the mechanisms and factors controlling the intricate behaviour of trace metals, their interactions, uptake and effect in natural systems. Traditional risk assessment methods usually built on quite crude toxicity tests done in unrealistic "laboratory waters," and did not consider natural conditions. In contrast, modern approaches now increasingly involve the full utilisation of site-specific factors, which are decisive for the formation of bioavailable and toxic metal forms.

Audience: This book provides excellent guidance not only to scientists focusing on the assessment of the ecological risk of metals, but also to authorities, decision makers in industry, educational staff and the interested public concerned with the occurrence and fate of trace metals.

Hazard assessment of a compound (xenobiotic) discharged to the aquatic environment requires data on both exposure and effects to various components of the ecosystem. The multitude of ecological gradients in the Baltic Sea is used as a background example for discussing the complexity of the issue and the need for new approaches. Therefore, this book attempts to go beyond the simplistic, standardized short-term laboratory tests traditionally used as a basis for hazard assessment of chemicals, and gives strong emphasis to the interpretation of ecotoxicological data in their real, ecological context, pointing out the need to consider the natural mortality distribution of the population under study, the role of keystone species and of species with broad ecological niches versus those with narrow, specialized niches.

The particular behavior of trace metals in the environment is determined by their specific physico-chemical form rather than by their total concentration. The introduction of atomic absorption spectrometry has lead to a plethora of scientific papers and reports in which metal concentrations in the environment are only reported as total concentrations. Only recently has the need for improved knowledge on the various forms and bioavailability of metals been realised. Considerable research effort is now devoted to measuring the concentrations of trace metals in surface waters. Efforts are made to couple chemical analytical techniques to process-related biological problems. The proceedings of the workshop on "The Speciation of Metals in " "Water, Sediment and Soil Systems" held in Sunne, Sweden, comprise these efforts and show aspects for further cooperation between analytical chemists and biologists.