The book you are just going to read represents the greater part of the papers presented at the International Conference on Industrial and En- vironmental Xenobiotics, held in Prague, 1980, and some contributions by those who could not come. The first aim of the meeting was to fol- low the tradition set up by the first conference in 1977. Again, we in- vited biochemists, pharmacologists, and toxicologists from both East and West, who were involved in the study of disposition, biotransforma- tion, and toxicity of important kinds of industrial and environmental pollutants, to promote the exchange of ideas and opinions on priorities in this area of the study of human environment. The invited contributions offer an excellent survey of and pro- found insight into specific areas of toxicology and disposition of metals and organic chemicals, and the series of papers on specific subjects bring fresh information on the biotransformation and mechanisms of toxic action of several industrially important solvents tmd monomers of plastics. Rather than from the Preface, the reader should seek guidance from the Index, which clearly shows the overlapping of this area of toxicology with the latest results in biochemistry. We gratefully acknowledge the understanding, care, and preciSion of the publisher that made this book possible. The Editors Contents Metals Metabolic Factors in the Distribution and Half Time of Mercury After Exposure to Different Mercurials 1. Magos. With 1 Figure . . . . . . . . . . . . . . . . . . .. . . . 1 . . . . . Biliary Excretion of Metals M. Cikrt. With 9 Figures. . . . . . . . . . . . . . . . . . . .. . . 17 . . . . .