About the editor WERNER STUMM is Professor and Head of the Institute for Water Resources and Water Pollution Control associated with the Swiss Federal Institute of Technology in Zurich, Switzerland. He received the Tyler Prize for Environmental Achievement, the Albert Einstein World Award of Science, the Monsanto Prize for Pollution Control, and has been awarded numerous international honorary degrees. He is the author of Aquatic Chemistry (Wiley-Interscience, 1970;Second Edition, 1981; Japanese translation, 1974; Chinese translation, 1987) and Gewasser als Okosysteme (with R. Kummert), and ha