Most people associate fluoride with the practice of intentionally adding fluoride to public drinking water supplies for the prevention of tooth decay. However, fluoride can also enter public water systems from natural sources, including runoff from the weathering of fluoride-containing rocks and soils and leaching from soil into groundwater. Fluoride pollution from various industrial emissions can also contaminate water supplies. In a few areas of the United States fluoride concentrations in water are much higher than normal, mostly from natural sources. Fluoride is one of the drinking water contaminants regulated by the U.S. Environmental Protection Agency (EPA) because it can occur at these toxic levels. In 1986, the EPA established a maximum allowable concentration for fluoride in drinking water of 4 milligrams per liter, a guideline designed to prevent the public from being exposed to harmful levels of fluoride. Fluoride in Drinking Water reviews research on various health effects from exposure to fluoride, including studies conducted in the last 10 years.

The book mainly introduces readers to the development and current status of water quality criteria (WQC) in China and other countries or areas, and proposes a minimum toxicity data requirement (MTDR; i.e., six species from three phyla) as the principle metric for deriving WQC in China. Further, ten model species from 4 different phyla are recommended as domestic test species, and the methodologies for deriving aquatic life criteria, sediment criteria, ecocriteria and nutrient criteria in China are also described in detail. In order to demonstrate the methods, several representative chemical pollutants and aquatic environments are highlighted as examples. The book provides important references for future WQC-related research in China, which will make it of great interest to researchers and graduate students in the fields of environmental science, ecology and aquatic science etc.

This document presents EPA's recommended Methodology for developing ambient water quality criteria as required under Section 304(a) of the Clean Water Act (CWA for States & Tribes' needs). The Methodology is guidance for scientific human health assessments used by EPA to develop, publish, & from time to time revise, recommended criteria for water quality accurately reflecting the latest scientific knowledge. Chapters: introduction to water quality criteria & standards & ambient water quality criteria (AWQC) methodology; clarifications on the methodology, risk characterization, & other issues for developing criteria; risk assessment; exposure; & references.