The seventh edition of Casarett and Doull’s Toxicology: The Basic Science of Poisons, as the previous six, is meant to serve primarily as a text for, or an adjunct to, graduate courses in toxicology. Because the six previous editions have been widely used in courses in environmental health and related areas, an attempt has been made to maintain those characteristics that make it useful to scientists from other disciplines. This edition will again provide information on the many facets of toxicology, especially the principles, concepts, and modes of thoughts that are the foundation of the discipline. Mechanisms of toxicity are emphasized. Research toxicologists will find this book an excellent reference.