Michael K. Peterson, M.E.M., DABT, ATS is Senior Principal at Gradient and a board-certified toxicologist and risk assessor with over 25 years of experience evaluating the human health toxicity of environmental chemicals, particles, and fibers. He is a Director on the Washington Governor’s Industrial Safety and Health Advisory Board, and a past President of the Society of Toxicology’s Occupational and Public Health Specialty Section.