This fourth edition continues to provide a link between occupational health and clinical practice. It covers target organ systems that can be affected by hazardous exposures in workplaces, and it focuses on the clinical presentations, investigations and management of affected individuals. The book is targeted at all those who are interested in the interaction between work and health, and how occupational diseases and work-related disorders may present. We have retained consideration of some special issues relevant to occupational medicine practice in Section 2 of this new edition.The main emphasis continues to be prevention of disease and early detection of health effects. This edition of the book has been updated to include new materials, topics, and references. We have retained a few of the previous case studies and illustrations, and introduced several new ones. There are new chapters on audit and evidence-based practice and on occupational cancer. We trust that this edition addresses many of the recommendations that were provided by readers of the previous edition.We have again asked international experts to author many of the chapters. Some of the authors are from Asia, and others from the US, UK, Europe, the Middle East and Australia. All the authors will have either clinical or academic experience in occupational medicine practice.The book will be of interest to medical practitioners, especially those in primary care and doctors intending to pursue a career in occupational medicine. It would also be relevant for non-medical health and safety professionals wanting to know more about health effects resulting from occupational exposures. Other groups who may find this edition useful as a ready reference are medical students, occupational health nurses, or clinical specialists in fields such as dermatology, respiratory medicine or toxicology.