Dr. Andrey Korchevskiy, PhD, DABT, CIH, is a diplomate of the American Board of Toxicology (DABT) and a certified industrial hygienist (CIH), USA. He is the Director of Research and Development at Chemistry & Industrial Hygiene, Inc. (C&IH) (Lakewood, Colorado). Dr. Korchevskiy holds separate PhD degrees in Applied Mathematics and Biology. He has over 150 publications in various peer-reviewed journals and was a leading editor and author of a monograph on risk assessment for asbestos and other fibrous minerals. He has also published works in the area of the theory of numbers, his favorite area of mathematics.Dr. Ann Wylie, PhD, holds a BA from Wellesley College and a PhD from Columbia University, USA. She joined the faculty at the University of Maryland in 1972, where she has taught courses in optical mineralogy, mineralogy, economic geology, X-ray diffraction, and ore microscopy. She currently holds the rank of Emerita Professor and Distinguished Scholar Teacher in the Department of Geology. She is an elected fellow of the Geological Society of America and the American Association for the Advancement of Science. She is also a senior scientific advisor for Chemistry & Industrial Hygiene, Inc. Her work has been published in both the mineralogical and toxicological literature. She has served as a consultant to both government and industry.