About the Editors...Terry Roberts obtained his BSc in Chemistry and PhD at the University College of North Wales, Bangor. He then went to Case Western Reserve University in Cleveland, Ohio to do research in organic chemistry before taking a Research Associateship at the University of St Andrews. He joined Shell Research at Sittingbourne in 1969 to work on metabolism of pesticides in plants and soils, and subsequently took responsibility for metabolism, residues chemistry, environmental fate and ecotoxicology activities. In 1990 he joined Corning Hazleton Ltd and is currently Director of Agrochemical and Environmental Services. Terry Roberts is the author of many research papers and reviews on agrochemical environmental topics and of a book entitled Radiochromatography. He is a Fellow of the Society of Chemistry and Secretary to the Applied Chemistry Division of IUPAC. He has recently been appointed Editor-in-Chief of the new Wiley series on "Agrochemicals and Plant Protection". Philip Kearney received his BS and MS degrees from the University of Maryland in 1955 and 1957, and his PhD from Cornell University in 1960. For many years he was a research leader at the Pesticide Degradation Laboratory at USDA (United States Department of Agriculture), Beltsville, Maryland. Until recently Philip Kearney was Deputy Area Director, Natural Resources Institute, Agricultural Research Service (ARS), at Beltsville with major areas of interest in water quality, food safety and sustainable agriculture. His research interests include environmental chemistry, biotechnology and waste water treatment. Philip Kearney is currently Adjunct Professor at the Water Resources Research Center, Department of Chemistry, University of Maryland. His involvements in international activities include leading the IUPAC Agrochemicals Commission and Applied Chemistry Division and he was President of the Eighth International Congress of Pesticide Chemistry, held in Washington in 1994. Philip Kearney has received many awards including the Burdick and Jackson Award from the American Chemical Society and the ARS Distinguished Scientist of the year 1986.