This book offers a comprehensive review of disinfection by-products (DBPs), exploring various aspects from detection methods and precursors to their potential health risks, regulation, and future implications. This book is also a memorial to the 50th anniversary of the first major DBP report in 1974 by Dr. Rook, who identified chloroform in chlorinated drinking water, initiating the study of DBPs. For half a century, toxicologists and chemists have been identifying more DBPs, understanding their formation mechanism, and evaluating their health effects on the public. Divided into four parts, the book commences with an introduction to the general knowledge of DBPs, shedding light on the significance of DBPs and their impact on water quality. It also delves into the detection methods employed to identify and quantify DBPs, offering readers invaluable insights into cutting-edge techniques and emerging technologies, and explores the sources and characteristics of DBP precursors. In Part II, several expert contributors provide an overview of individual DBPs, including halogenated aliphatic, iodinated, aromatic, and heterocyclic DBPs, discussing their properties and potential implications. The discussion extends to nitrogenous DBPs, the group of nitrosamines, and inorganic DBPs as well. Part III provides an authoritative perspective on the relationship between energy consumption, climate change, and DBP formation, offering also insights into DBPs in the context of water treatment plants, water reuse plants, swimming pools, and everyday life. The book closes with a section devoted to the health effects of DBPs, where particular attention is given to the analysis of the toxicity and health risks associated with DBPs. In this section, readers will find more about the potential adverse effects of DBPs on human health and current research on risk assessment and management strategies. In today's era of water scarcity and increasing demands for safe drinking water, the presence of DBPs has emerged as a critical concern in the field of public health. This book is, therefore, an invaluable resource for researchers, water treatment professionals, public health officials, and policymakers seeking a comprehensive understanding of DBPs.