W. GEORGE FONG, a widely recognized expert in the pesticide residue field, is the Environmental Administrator of the Florida Department of Agriculture. His published work includes the chapter on toxicology in the Encyclopedia of Chemical Technology, Fourth Edition, available from Wiley. H. ANSON MOYE is Professor in the Food Science and Human Nutrition Department at the University of Florida. He has published numerous papers and articles in a career that spans nearly three decades. JAMES N. SEIBER is Director of the Center for Environmental Sciences and Engineering at the University of Nevada in Reno. Dr. Seiber is the coeditor of Fumigants: Environmental Fate, Exposures, and Analysis and Treatment and Disposal of Pesticide Wastes. JOHN P. TOTH is Coordinator of the mass spectrometry facility at the University of Florida's Institute of Food and Agricultural Sciences. Among others, his research interests include the application of mass spectrometry to pesticide residue analysis.