Paul Francis Hahn received his bachelor's degree in chemistry from MIT and his doctorate in biochemistry from the University of Rochester. He pioneered the use of radioisotopes in cancer research while on the faculty of the Vanderbilt University School of Medicine. As associate professor of biochemistry at Vanderbilt from 1943-1948, Hahn focused his research primarily upon the use of radioisotopes for the treatment of cancer, leukemia, and Hodgkin's Disease. Hahn then served as professor of experimental oncology and Director of the Cancer Research Laboratory at Meharry Medical College (1948-1960). From 1960 until his death in 1967, Hahn worked with the Public Health Service as assistant to the director of its National Center for Radiological Health in Bethesda, Maryland.

Hahn is the author of Therapeutic Use of Artificial Radioisotopes, a medical book published in the mid-1950s and regarded as a classic in the field. Dr. Hahn helped evacuate the effects of nuclear fallout after tests at Bikini Atoll in the 1940s. Additionally, he was a member of the board of medical consultants to the Oak Ridge Institute for Nuclear Studies.