Summarizes current understanding of the complex interactions between chemicals, the immune system, and target organs that lead to manifestations of allergic hypersensitivity and autoimmunity. Noting that the incidence of allergic disorders has increased significantly in many countries, the book responds to the urgent need to improve methods for detecting potential allergens and predicting their effects in both individuals and populations. The need for better preventive strategies and therapeutic options is also considered, particularly in view of the high costs of allergic disorders in terms of health care and time lost from work. Addressed to researchers, the book concentrates on what is known about the mechanisms of sensitization and autoimmunity elicited by numerous industrial chemicals, adjuvant environmental factors, such as air pollution, tobacco smoke, and ultraviolet radiation, and food allergens with a proven involvement of the immune system. Although a large number of allergies are covered, particular attention is given to asthma and contact dermatitis as major occupational diseases undergoing intensive investigation. Throughout, a special effort is made to identify lines of investigation that will lead to a better understanding of fundamental mechanisms and thus improve the prospects for treatment and prevention. Over 1000 references to the literature are included. The book opens with a detailed explanation of the structure and functional processes of the immune system, followed by a discussion of the mechanisms by which chemicals can disrupt these functions. Also discussed are fundamental concepts of immunosuppression, immunodeficiency, and immunological tolerance that help explain the mechanistic basis of sensitization, allergic responses, and autoimmunity. Chapter two provides an overview of mechanisms involved in four major types of hypersensitivity and in autoimmunity. Mechanisms are illustrated with examples of diseases - from occupational asthma, through myasthenia gravis, to chronic beryllium disease - where exposure to environmental chemicals might play a role. The numerous hypotheses put forward to explain the mechanisms of autoimmune reactions are also critically assessed. Factors influencing allergenicity are covered in chapter three, which concentrates on the many complex endogenous and exogenous factors that govern the induction of allergic responses. Against this background, chapter four discusses clinical aspects of the most important allergic diseases. These include allergic contact dermatitis, atopic eczema, allergic rhinitis and conjunctivitis, allergic asthma caused by contact with chemicals, food allergy, and autoimmune diseases associated with drugs, chemicals, and environmental factors. Each disease is profiled in terms of its epidemiology, clinical manifestations, etiology, pathogenesis, diagnosis, and strategies for treatment and prevention. The remaining chapters review the epidemiology of asthma and allergic disease, including trends over time in different geographical regions, describe procedures for hazard identification through the demonstration of allergenicity, and explain how the principles of risk assessment can be applied to allergy. The book concludes with a glossary of terms, followed by 15 precise recommendations for the protection of human health and a list of priorities for further research.