About the editors EVERT NIEBOER is Professor of Toxicology, Department of Biochemistry and Occupational Health Program, McMaster University, Ontario. Since his arrival at McMaster in 1980, Dr. Nieboer's research interests have centered on the human toxicity of metals with an emphasis on physicochemical, metabolic, and molecular aspects of nickel carcinogenesis, the renal clearance and toxicity of metals, and the use of biological monitoring to assess worker exposure and health risks. Dr. Nieboer's research team at McMaster has prepared a number of health effects documents for industrial and governmental agencies. The author's extensive published work has centered on the biological roles and trace analysis of metals. Dr. Nieboer received a BSc in chemistry and an MSc in analytical chemistry from McMaster University and a PhD in analytical/organic chemistry from the University of Waterloo. JEROME O. NRIAGU is a research scientist with the National Water Research Institute, Burlington, Ontario, and Adjunct Professor at the University of Waterloo. He is the editor of the Wiley Series in Advances in Environmental Science and Technology and has edited, among many other volumes, Environmental Impacts of Smelters, Toxic Contaminants in the Great Lakes, and Aquatic Toxicolog. Dr. Nriagu received the BSc and DSc degrees from the University of Ibadan, Nigeria, an MS from the University of Wisconsin, Madison, and a PhD in geochemistry from the University of Toronto. He has published extensively in leading geochemical and environmental science journals, and has received a number of awards for his work.