Human beings vary in their sensitivity to environmental chemicals. Some people are particularly sensitive to certain chemical compounds and may, therefore, develop adverse effects as a result of exposures that are otherwise considered safe. Considerable variation in susceptibility may be determined by inherited patterns of metabolism. Research in several fields is now beginning to uncover the mechanisms and the significance of such inherited hypersusceptibility to environmental chemicals. This evidence will be of crucial importance for successful protection of all individuals against toxic chemicals. This book, which is based on a WHO consultation, provides an overview of current knowledge on genetic predisposition to chemical toxicity. It reviews the experimental, pharmacological, toxicogenetic and epidemiological evidence and considers the implications for preventative action and future research. The important ethical and legal aspects are covered, as is the importance of genetic factors in the pathogenesis of ischaemic heart disease and major types of cancer. Written and edited by an international team of experts, this book should be a vital reference source for industrial and environmental health officers, health care planners and physicians and researchers in toxicology, pharmacology, genetics, clinical chemistry, epidemiology and occupational health.