In response to increasing information arising from the scientific community, the news media reported that pharmaceuticals have been detected in the drinking water of 24 major metropolitan areas across the United States. These reports raised concerns about the potential impact of these pharmaceuticals on human health and the environment. Pharmaceuticals are a particular concern because they are designed to interact with human or animal physiology. Much is known about the therapeutic uses of pharmaceuticals, but little is known about their potential risk to human health from long-term exposure through drinking water. This book examines the research reported in the detection of pharmaceuticals in the U.S. water supply.