Leonidas D. Marinelli
Written by L.D. Marinelli, August, 1974
Leonidas D. Marinelli, at the time of his retirement in 1971, was a Senior Scientist in the Radiological Physics Division at Argonne National Laboratory—having been with the Laboratory since 1948. He served as Associate Director (1948-1963) and Director of the Radiological Physics Division (1963-1967.)
Marinelli began his career in 1929 as a research technician in the Physics Department of Memorial Hospital, New York City, and remained with that hospital until 1948 when he terminated his employment as Physicist-in-Charge. He obtained his M.A. degree in 1936 and completed the course requirements for a Ph.D. degree in Columbia University's Division of Mathematical and Physical Science in 1938.
While at Memorial Hospital, he devised an original method for accurately measuring very high ohmic and non-ohmic resistances. He was one of the earliest investigators to apply X-ray radiation to industrial uses and designed many semi-automatic devices for the safe handling of large quantities of radium for routine use. He played a decisive role in the first treatment of metastatic thyroid cancer with radioactive iodine, laid the foundations of radiation dosimetry in the internal use of radioisotopes, and was the first to use radioisotopes to study metabolic effects of X-radiation on mammalian tissues.
Marinelli was with Cornell University Medical College as an assistant professor of Radiology from 1944 until 1949 and headed the Division of Physics and Biophysics of Sloan-Kettering Institute from 1945 until 1949. Immediately prior to joining the Argonne staff, he was a visiting lecturer on biophysics at the University of Chicago, where he was an associate professor of radiology in the medical school.
At Argonne, Marinelli is credited with playing a key role in the study of radioactivity in human beings by leading investigations that culminated in the gamma-ray measurements in vivo of the total potassium content in normal people and, later, its detailed localization. He worked closely with other Argonne National Laboratory investigators who studied radium-injected patients at a state hospital. He has significantly contributed to the leading role played by the Radiological Physics Division in the field of low-level γ-ray spectrometry and its applications to nuclear medicine, radiation protection, and in vivo and in vitro fallout surveys. Through his efforts, special biophysical studies on radiation-damaged bone have been established. These have led to a better understanding of the basic metabolic processes in bone and the radiation dosimetry of bone seekers.
Marinelli is designer of a special type of beaker for the determination of gamma-ray activity in liquids which bears his name and is used extensively throughout the world. His many other achievements in cancer and radiation fields are described in about 100 papers published in professional journals.
He has served on the following committees at various times: Standardization Committee of the Radiological Society of North America, National Research Council's Committee on Growth, on Nuclear Science, National Advisory Committee on Radiation Protection, International Committee on Radiation Protection, the Commission on Radiological Units of the American College of Radiology, Advisory Committee to the AEC Division of Biology and Medicine, the World Health Organization's Expert Advisory Panel on Radiation, and the Advisory Committee to the Bureau of Radiological Health of the Public Health Service.
In addition to serving as an editorial board member of Cancer, Radiation Research, Minerva Nucleare, Health Physics (Journal), Marinelli is a fellow of the American Association for the Advancement of Science and is a member of the American Radium Society, American College of Radiology, Harvey Society, New York Roentgen Ray Society, American Physical Society, and the Radiological Society of North America.
Leonidas D. Marinelli: Cold War Scientist
By Judith Marinelli Godfrey, M.A., University of Chicago;
Glenn F. Flux, Ph.D.,
Feb. 2023_Radiation Research journal
ABSTRACT: Knowledge about the long-term effects of low-level ionizing
radiation in the human body, urgently needed after the first Atomic bomb in
1945, was pioneered by American scientist Leonidas D. Marinelli.
In 1950, he designed and led the major 25-year study at the Argonne National Laboratory, Illinois, which yielded a major understanding of the anthropological effects of radiation. His investigations produced the evidence for radium-induced cancer found in Elgin State Hospital patients injected with medical radium in 1930, Illinois watch dial painters who ingested radium ink in the 1920s and ‘30s, in German uranium miners, and in Marshall Islanders at atomic tests in the South Pacific Ocean, workers in nuclear industries, and Danish Thorotrast patients
contaminated with radium from the decay of thorium inside their bodies.
Marinelli developed the first formalism of biological dosimetry in 1942, applied it to the first treatment of metastatic thyroid cancer in 1946, and developed new cancer treatments at the Memorial Hospital-Sloan-Kettering Institute which Time Magazine featured in 1949. At Argonne Laboratory, Marinelli developed the dosimetry and spectrometry to extract minimal burdens of radioactivity in humans and their distribution and variation in biological tissues.
At international conferences, Marinelli personally invited scientists to duplicate his Whole Body Counter, apply it to study low-level gamma ray radiation in bone, and gather bone data worldwide. He urged the importance of Thorotrast studies and the gathering more data. Hospitals discontinued Thorotrast injections. From the vast data gathered, Marinelli extracted unprecedented low level measurements . "Marinelli's greatest single contributions were to the complex subject of human radioactivity…,” wrote Harald H. Rossi, Director of Columbia University Radiological Research Laboratory in 1975.
Dosimetrist Glenn Flux describes the enduring legacy Marinelli laid regarding effects of radiation delivered from radionuclides. Marinelli’s methods
and calculations are desirable for the delivery of personalized radiation
treatment in the present day, and are of extreme relevance as the field grows
exponentially for cancer treatment. Marinelli’s daughter, Judith, seeks to present the practicality and humanism of her fathers contributions in his 42 year career. She reveals his deep patriotism for the new country he adopted when he emigrated from Italy at the age of nineteen. She points to his priority for radiation protection, borne in the decades he served the National and International Radiation Protection
Commissions, shared information with international colleagues, and with the
United States Health Service. Above all, she portrays him a loving father, faithful to science, to his wife, to his Catholicism, to the respect for other people--- and to the Italian opera that so delighted him.