ABSTRACT
Environmental contamination with metals is a serious problem worldwide. All metals may be toxic above a certain threshold. No less than one-fourth of all metals are included in priority pollutant lists, and some metals such as mercury, lead, and cadmium rank highest among those of regulatory concern (Figure 12.1). Furthermore, metals are ubiquitous, at least in trace concentrations, and are remarkably diverse. More than half of all chemical elements are metals, and occur as dissolved ions and in a wide variety of inorganic compounds, metal complexes, and organometallic compounds, and form myriad alloys.
