API PUBL 4666 : 1999

This review focuses on laboratory data regarding the effects of common cations and anions on both freshwater and marine organisms. While a given water can have a variety of constituents, only a few are considered to be common. The major cations are calcium (Ca2+), magnesium (Mg2+), potassium (K+), sodium (Na+), and strontium (Sr2+), and the major anions are bicarbonate (HCO3−), borate (B4O72−), bromide (Br−), chloride (Cl−), fluoride (F−), and sulfate (SO42−). This document provides a general summary of the results of toxicity studies on ions and explores the physiological effects of those ions on a tissue and cellular basis.

Section 1 describes some of the current regulatory schemes concerned about ion toxicity. Section 2 summarizes the ionic composition of natural waters in the world, both fresh and saline. A review of some of the sources of high TDS waters is provided in Section 3, along with a discussion of Toxicity Identification Methods (TIE) and what techniques are effective in separating toxicity related to common ions from toxicity due to other constituents. Section 4 is a review of the toxicological data for different ions. Section 5 explores the physiological function of ions and the various models of ion regulation that exist in different taxa. A summary is included in Section 6. References, a Glossary, and a Bibliography follow the summary.

Information for this review was gathered in three ways. First, several computer databases were searched for information related to the toxicity of the common ions (listed above) to aquatic organisms. Those databases included AQUIRE, Biosis Previews®, Compendex®, Oceanic Abstracts, Aquatic Science Abstracts, CAB Abstracts, Inside Conferences, Wilson Applied Science and Technology Abstracts, Water Resources Abstracts, WATERNET™, GEOBASE™, IAC Newsletter DB™, Enviroline®, Pollution Abstracts, Environmental Bibliography, and SciSearch®. Second, a manual literature search was conducted to gather information that might not be found in the databases. Finally, there was direct communication with researchers involved in ion toxicity studies.