Mercury is one of the most significant environmental pollutants due to its persistence, mobility, and high toxicity. This book provides a comprehensive and up-to-date overview of this element, covering its physicochemical properties, biogeochemical cycle, speciation, toxicokinetics, and mechanisms of toxicity, as well as its effects on human health and the environment. It analyzes biomonitoring, analytical methods for its determination and speciation, the diagnosis and treatment of poisoning, international regulations-including the Minamata Convention-and the main remediation technologies. It also presents the latest trends in analytical chemistry, nanotechnology, biomarkers, advanced materials, and environmental monitoring strategies. With an interdisciplinary approach and supported by an up-to-date bibliography, this book serves as a reference tool for researchers, educators, students, and professionals in the chemical, biological, environmental, and health sciences.