With remarkable vision, Prof. Otto Hutzinger initiated The Handbook of Envir- mental Chemistry in 1980 and became the founding Editor-in-Chief. At that time, environmental chemistry was an emerging ?eld, aiming at a complete description of the Earth's environment, encompassing the physical, chemical, biological, and geological transformations of chemical substances occurring on a local as well as a global scale. Environmental chemistry was intended to provide an account of the impact of man's activities on the natural environment by describing observed changes. While a considerable amount of knowledge has been accumulated over the last three decades, as re?ected in the more than 70 volumes of The Handbook of Environmental Chemistry, there are still many scienti?c and policy challenges ahead due to the complexity and interdisciplinary nature of the ?eld. The series will therefore continue to provide compilations of current knowledge. Contri- tions are written by leading experts with practical experience in their ?elds. The Handbook of Environmental Chemistry grows with the increases in our scienti?c understanding, and provides a valuable source not only for scientists but also for environmental managers and decision-makers. Today, the series covers a broad range of environmental topics from a chemical perspective, including methodol- ical advances in environmental analytical chemistry.