Dr Landa holds an M.S. and Ph.D. in soil science from the University of Minnesota, and has been the U.S. Geological Survey since 1978. His research focuses on radionuclide and metal mobility in soil and aquatic environments, and has included studies of uranium mill tailings, radium processing residues, oil field brines, and indoor radon. He participated in the IAEA International Chernobyl Project, and in studies of radioactive contamination in the Arctic regions. Dr Landa’s interest and publication record in the history of science spans from the late 1970’s, with an early focus on the history of the radium processing industry—a spin-off of his research on present-day soil contamination at these sites. This historical research resulted in a paper in Scientific American (1982) and a monograph published by the Colorado School of Mines (1987). His recent historical focus has been on the history of soil science; he has co-authored papers on soil physicists Lyman Briggs and Edgar Buckingham (SSSAJ 2003, 2005). His co-authored paper on Albert Munsell appeared in the September-October 2005 issue of American Scientist. Dr Landa served as the Chair of the SSSA Committee on the History, Philosophy and Sociology of Soil Science in 2004. He is presently the Chair (2006-2010) of IUSS Commission 4.5 on the History, Philosophy and Sociology of Soil Science. As part of that activity, he and Vice Chair Christian Feller are editing a book “Soil and Culture”, to be published by Springer in 2009.