David G. Rickerby, PhD, is a senior scientific officer in the Institute for Environment and Sustainability at the European Commission Joint Research Centre, Ispra, Italy. After earning a doctoral degree from the University of Cambridge, he carried out postdoctoral research at the Pennsylvania State University. His present research interests involve evaluation of the potential risks and benefits of nanotechnologies, including development of risk assessment tools and methodologies. He was one of the group of international experts who coauthored a chapter on nanotechnology and the environment for the UNEP GEO Year Book and is a member of the OECD Working Party on Manufactured Nanomaterials, Steering Group 9 on the Environmentally Sustainable Use of Nanotechnology.