Other academic advisors Gioacchino Failla Name Leonidas Marinelli Fields Radiology | Known for Marinelli beaker Alma mater Cooper Union Doctoral advisor Gioacchino Failla | |
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Born 28 November 1906
Argentina ( 1906-11-28 ) Institutions Memorial Hospital
Known today as
Memorial Sloan Kettering Cancer Center
Argonne National Laboratory Died September 13, 1974, Hinsdale, Illinois, United States Institution Memorial Sloan Kettering Cancer Center, Argonne National Laboratory | ||
Leonidas D. Marinelli, (28 November 1906 - 13 September 1974), was born in Argentina and died in Hinsdale, DuPage County, Illinois was an American radiologist, health physicist and inventor.
Contents
Life and Education
Marinelli was born of Italian parents in Argentina and in 1906 the family moved back to Italy where rather modest circumstances permitted him only a technical high school education. He immigrated to New York in the late 1920s and supported himself as a meter tester working his way through Cooper Union. His opportunity came with a technician's position in Gioacchino Failla's laboratory at Memorial Hospital (New York City, New York), (known today as Memorial Sloan Kettering Cancer Center), where the groundwork was being done on the quantitative study of X-rays for medical use. By 1933 he was joining Failla, Edith Quimby, and John E. Rose as a coauthor.
Dr. John E. Rose - Health Physicist
Dr. John E. Rose would become Health Physics and radiological physics division director at Argonne. Rose was involved with radiation detection instrumentation, including hand and foot monitors and other detectors. Further note regarding Rose: it was in the Manhattan District of U.S. Army Corps of Engineers that the name "health physics" was born, and great advances were made in radiation safety. From the beginning, the leaders of the Manhattan District recognized that a new and intense source of radiation and radioactivity would be created, and thus, in the summer of 1942, asked Ernest O. Wollan, a cosmic ray physicist at the University of Chicago, to form a group to study and control radiation hazards. Thus, Wollan was the first to bear the title of health physicist. He was soon joined by Carl G. Gamertsfelder, recently graduated physics baccalaureate, and Herbert M. Parker, the noted British-American medical physicist. By mid 1943, six others had been added: Karl Z. Morgan, James C. Hart, Robert R. Coveyou, Ole G. Landsverk, Ph.D. of the Ryerson Physical Laboratory, University of Chicago, L.A. Pardue and Dr. John E. Rose.
Within the Manhattan District, the name health physicist seems to have been derived in part from the need for secrecy (and hence a code name for radiation protection activities) and the fact that there was a group of mostly physicists working on health related problems. Thus, their activities included development of appropriate monitoring instruments, developing physical controls, administrative procedures, monitoring areas and personnel, and radioactive waste disposal—in short, the entire spectrum of modern day radiation protection problems. It was in the Manhattan District that many of the modern concepts of protection were born, including the rem unit, which took into account the biological effectiveness of the radiation, and the maximum permissible concentration (MPC) for inhaled radioactivity. Indeed, it was in the Manhattan District that modern day radiation protection effects, born in the early days of x-ray and radium, realized their maturity.
Career and Profession
In 1935 Marinelli became an Assistant Physicist.
The 1940s saw Marinelli blossoming into an independent scientist. The responsibilities of laboratory director were thrust upon him, by the departure of Failla and Quimby from Memorial, while the explosive growth of radiation medicine gave them further scope.
In 1941 his papers dealt with postirradiation blood studies and with early tracer work on cancer; in 1942 with the production of chromosomal breaks in plant cells and with the theory of time distribution of radiation treatments. Then came the breakthrough of radioiodine therapy, followed by autoradiography techniques and by a Review of Modern Physics report on beta rays. A modicum of economic ease permitted him now to enjoy fully his role of husband and father of a wonderful family.
In 1948 he moved to the Argonne National Laboratory, with a position on the University of Chicago faculty. Here, with John Rose, he provided early leadership and scientific direction of the Radiological Physics Division.
Maturity was marked by authorship of textbook articles on dosimetry in the Annual Review of Nuclear Science, in Radiation Biology, and in the Handbook of Medical Radiology. His studies of physics dealt now with electron diffusion from point sources in air and with the cosmic ray background. In radiology he pioneered the detection of minimal burdens of radioactivity in humans, studying their distribution and variation in tissues and the epidemiology of chronic low levels of radiation. The Center for Human Radiobiology, which now has the responsibility for all AEC-supported research on the effects of internally deposited radioisotopes, grew out of his effort.
Nature granted Marinelli a generous amount of vitality and healthy spirits, but then allowed them to be sapped by early onset of health problems that one would hope to face only later in life. Thus, a shadow of worry and sadness came to surround his later years to the deep sorrow of all those that had been blessed by his warm contact.
Marinelli beaker
The following footnote regarding the Marinelli beaker is found in a report by R.F. Hill, G.J. Hine and L.D. Marinelli (1950) of the Sloan-Kettering Institute in New York:
“This equipment first designed by one of the present authors (L.D.M.) and in use in this laboratory since 1943, can now be obtained from Technical Associates, Inc. Glendale, California.”
Development
In the 1940s and 1950s, the main application of the Marinelli beaker was the analysis of I-131 in liquids (e.g., urine). The original version of the Marinelli beaker, pictured here, consisted of a pyrex/glass laboratory beaker with a central hollow tube projecting from the bottom. A detector, usually a glass GM tube designed for gamma counting, was positioned in the central tube while the beaker was filled with the sample. Since the sample effectively surrounded the detector, the counting efficiency was greater than would be the case if the sample were in any other type of container.
A laboratory often used Marinelli beakers of different sizes - small beakers for small volume samples and large beakers for large volume samples. While it was always possible to increase the volume of a small sample by dilution so that it would fill a large beaker, this sacrificed counting efficiency.
Until the mid-to-late1950’s when liquid scintillation countings came along and gamma scintillators (NaI crystals) became larger and more widely available, the major options for counting liquid samples were Marinelli beakers, jacketed (annular) GM tubes, and dipping GM tubes . Since Marinelli beakers could hold larger volume samples than annular GMs, they had a higher counting efficiency for gamma rays. On the other hand, their efficiency for beta particles was lower than that of annular GM tubes because the betas had to penetrate the glass of the beaker as well as the GM tube wall. Dipping GM tubes, which were dipped into the radioactive solution, were primarily used for beta emitters. While the problem was not as severe as with the annular GM, they could be difficult to clean - a potential problem with long-lived radionuclides.
A different type of alternative was to dry the sample and count it with an end window GM or electroscope (e.g., the Landsverk Model L-75). However, the preparation of dried samples was difficult to perform in a reproducible manner and it risked the volatilization of the iodine.
As NaI detectors became more widely available, workers started to use the type of sample container that most people think of today as the Marinelli beaker: a relatively large plastic jar/beaker with an annular bottom that slid over the NaI crystal (e.g., Haigh, 1954 and Dratz, 1957). Sometimes referred to as a “well-bottom” container, the end of the well was sealed so that the container “hung” from the top of the detector.
Notes
Held a patent for "Apparatus for counting fast neutrons in the presence of gamma rays", US #2795703 A.