Dr. Robert Root is a Research Assistant Professor at the University of Arizona in the Department of Soil, Water, and Environmental Science. His research is in the area of metal(loid) transport and sequestration in the environment and contaminant bioaccessibility utilizing in vitro bio-assays. He applies advanced spectroscopic methods, in particular synchrotron X-ray methods, to characterize biogeochemical mechanisms controlling the fate of environmental contaminants in geomedia (e.g., soils, sediments, mine tailings, and dusts). Previously, Dr. Root was a NIEHS post-doc training fellow in the University of Arizona, College of Pharmacy researching the relation between molecular speciation and bioavailability of arsenic in geo-dusts released into the atmosphere at two U.S. Superfund sites in Arizona. His dissertation, “Arsenic mobility in suboxic environments: the role of phosphate competition and green rust mineralization”, examined the thermodynamic and kinetic controls of mineral transition and contaminant release in the environment, with special focus on arsenic release as a function of redox induced changes in iron mineralogy. Dr. Root's current interests include investigating the surface geochemistry of natural particles and the interaction of contaminants with natural and synthetic substrates to elucidate conditions of likely release and potential strategies of remediation.