Peter Santschi’s pioneering work and groundbreaking theories on the source and fate of radionuclides and colloids in the environment have become a research standard in the United States and abroad. When the Chernobyl disaster occurred in 1986, for example, Santschi oversaw the effort to assess the levels of resulting radiation. This led him to investigate the modifying effects of organic matter in soils and wetlands to potentially toxic radioactive iodine-129 and plutonium at US waste sites and in soils from Fukushima in Japan. He is determining how radioisotopes interact with organic substances, both underground and on the surface. This research could ultimately help shield humans from health risks related to the transportation, storage and disposal of radioactive materials. He also is researching ways to slowdown or stop the migration of the radioactive contaminants through surface and groundwater. During his career, he has advised 23 graduate students and 16 post-doctoral fellows. Many of his graduates now hold senior level positions in academia, government and the private sectors in different countries. He is Regents Professor of Marine Sciences at Texas A&M University at Galveston and of Oceanography at Texas A&M in College Station. Santschi earned an MS and Ph.D. from the University of Berne, Switzerland and joined the Texas A&M faculty in 1988.