Dr. Martin F Soto-Jimenez is a research geochemist with the ICMyL-UNAM in Mexico since 2004. Dr. Soto-Jimenez received a B.A. degree (Biochemistry) from Instituto Tecnologico de Mazatlan, a Master and Doctorate in Science in Marine Chemistry from Universidad Nacional Autonoma de Mexico in 1998 and 2002, respectively. He was a Postdoctoral researcher at the Boston University Marine Program (2002-2003) and Fulbrigther Scholar in the Department of Microbiology and Environmental Toxicology at U.C. Santa Cruz (2003-2004). Nowadays, Dr. Soto-Jimenez is a Visiting Scientist in the Department of Environmental Health of the Harvard School of Public Health. He is an expert in the geochemical fractionation of metals of solid matrices, on metal and nutrient cycling, diagenetic processes in the near surface environment, and understanding of isotope systematics and applications. His recent research is on the utilization of in vitro bioaccessibility protocols that mimics the human digestive tract and then to use it in the determination of the bioavailable fraction of metals in urban soils and dusts for assess human health risk. He has studied perturbed coastal ecosystems and urban areas in Mexico in the past 15 years using a wide range of geochemical techniques including sequential extraction protocols, trace analyses of metals (ICP/OES, ICP-MS, GF and FAAS), nutrient analysis (UV-Vis, CHN/O analyzer) and isotopic analysis (GC-IRMS, TIMS, HR and MC-ICP/MS). In addition to the proposed associate editorship with the Journal of Geochemical Exploration, Dr. Soto-Jimenez has served on the editorial board of The Scientific World Journal, and, as frequent reviewer for different peer-review journals.