Representative studies of the environmental significance of inorganic species (as opposed to total-element content) in water are reviewed. The effects of chemical forms on human health and on plant and animal life, and the roles of valence state, ionization, complexation, and adsorption in the transport and cycling of elements are considered along with factors affecting the distribution of elements and species in freshwater streams and impoundments, in estuaries, and in the sea. Information on the chronic effects on human health of trace inorganic pollutants in water is almost entirely limited to total elements because of an inability to distinguish among forms of an element. The elements of greatest concern with respect to the toxicity of different species are arsenic, chromium, lead, mercury, and selenium. In the toxicology of aquatic biota, there is a rapidly growing appreciation that both acute and chronic effects are strongly related to chemical species. The movement of inorganic pollutants in the aquatic environment is strongly influenced by adsorption of particular species on both mineral and organic particulates. No broadly applicable analytical techniques of adequate sensitivity are available for elemental speciation. This deficiency in analytical ability prevents the evaluation of research on toxicology and on transport of these chemical forms.

Includes bibliographical references (pages 51-99).