Contamination of the earth's ecosystems by potentially toxie metalsl metalloids is a global problem. It will likely grow with our planet's increasing populations and their requirements for natural resources (e. g. , water, food, energy, waste-disposal sites) and metals-based goods. The health impacts of pollution from the ingestion of heavy metals/metalloids via respiration, food, and drinking water are most often long-term and manifest themselves in many ways. These include, for example, disminution of mental acuity, loss of motor control, critieal organ dysfunction, cancer, chronie illnesses and con­ comitant suffering, incapacitation, and finally death. The incidence and geographie distribution of disease (epidemiology) has been well-documented historieally and in modern times for toxic metals­ triggered diseases in humans, animals and vegetation. The role of the environmental geochemist and colleagues in environ­ mental sciences is to scientifically evaluate how to manage metalsl metalloids at sources or in-situ so as to alleviate or eliminate their negative health impacts on living populations. This is initiated by identifying sources and by developing models of the physieal, chem­ ieal and biologieal controls on mobilization, interaction, deposition and accumulation of potentially toxie metals/metalloids in source systems and earth ecosystems. Prom this knowledge base, environ­ mental scientists (e. g. , geologists, chemists, biologists, environmen­ tal engineers, physicists/meteorologists) work together to develop Preface VI concepts and technologieal methodologies to preserve global eco­ systems. Their concerted efforts are equally focussed on devising strategems to remediate ecosystems still carrying heavy metals/metal­ loids pollutant burdens from ancient and modern societies.