[en] This text consists of a total of 74 chapters of which 68 are devoted to individual elements and derived substances. The introductory chapter contains general definitions and describes the manner in which each elemental chapter is organized. For each of these chapters the points covered include chemistry and distribution, technological uses, physiological processes, detoxification mechanisms, levels of tolerance, summary of ecotoxicity, and analytical chemistry as well as a list of references. In addition to the elements, a chapter is also devoted to radiotoxicity. Aside from a discussion of individual elements, the second chapter covers the chemistry of inorganic compounds from the point of view of essentiality in biological systems and the properties and interdependency of these compounds. The third chapter is a very brief description of general principles used in toxicology, with emphasis on metals. The fourth chapter deals specifically with the collection, storage, and handling of biological materials for subsequent analysis. This is followed by chapters on the individual elements. The final chapter is a summary containing various tables describing values for threshold limits, biological tolerance, and acceptable intake