In Memoriam: Melvin R. Sikov

1928-2005

by William J. Bair

On 4 August 2005, the radiation protection community lost its pioneer in developing our understanding of the risks to the embryo/fetus from the maternal intakes of radionuclides, and I lost a good friend and colleague of over 50 years. Melvin R. Sikov was born 8 July 1928 and graduated from high school in Detroit, Michigan. During 1947-1948 he served in the U.S. Army, stationed in Alaska. After earning a BS degree in biology and physics at Wayne State University in Detroit, in 1951-1952 he was awarded a fellowship in radiological physics at the Oak Ridge Institute of Nuclear Studies,  where he was one of Elda Anderson's students. Upon completion of his fellowship program, he was admitted to the University of Rochester School of Medicine and Dentistry as a graduate student in the Department of Radiation Biology and Biophysics, which was associated with the Atomic Energy Project. He studied under Dr. Thomas Noonan, receiving a PhD in radiation biology in 1955. He and Robert G. Thomas were recipients of the University of Rochester's (and the world's) second and third PhDs in radiation biology; since the degrees were awarded alphabetically, Mel took pleasure in needling Bob, claiming his was second and Bob's third.

A major event in Mel's life occurred on 1 June 1952 when he married Shirley Dressler, whom he had met at Wayne State University. Following their marriage, Shirley was employed in the Department of Statistics in the Atomic Energy Project.

Mel was fortunate in having Tom Noonan as his mentor. He was an outstanding physician/scientist and teacher with a wonderful sense of humor. He introduced Mel to the relatively new field of radiation effects on the female reproductive system and, in particular, the intricacies of radionuclide transfer across the placental membrane and the incorporation into fetal tissue.

After completing his PhD, Mel returned to Detroit as assistant professor of radiobiology in the Department of Radiology, Wayne State University College of Medicine. In 1961 he was appointed associate professor in the same department. He held concurrent staff appointments at Detroit Receiving Hospital and the Veterans Administration Hospital in Dearborn, Michigan. In these positions he taught graduate courses in radiation biology and isotopic tracer techniques, supervised graduate students, and lectured to medical students and radiology residents. His research continued along the lines of his doctoral work—radiobiology of tumors and effects of x radiation and ³²P on embryos, including neurological deficits and behavioral and developmental effects.

In 1965 Mel joined Dr. Bruce Stuart and me as the third University of Rochester graduate at Battelle's Pacific Northwest Laboratory's Biology Department at Hanford. Mel reported to Dr. Roy C. Thompson, a pioneer in radionuclide radiation biology. Mel advanced through several scientific positions, achieving the highest scientific rank. Upon his retirement in 1995 he was named Scientist Emeritus in the Molecular Biosciences Department. Mel also held adjunct faculty appointments at Oregon State University and the Joint Center for Graduate Studies, which subsequently became Washington State University Tri-Cities, where, at the time of his death, he held an appointment with the United States Transuranium and Uranium Registries in the Pharmaceutical Sciences Department, College of Pharmacy.

Mel considered himself a “specialist in reproductive and developmental toxicology and radiobiology, placental transfer and prenatal dosimetry of radionuclides, biological effects of radionuclides, and biokinetics of nutrients and toxic substances,” and indeed he was. His research led to 256 publications. Mel was especially skilled in developing successful collaborative efforts with other scientists and he mentored several postdoctoral staff.

At Hanford he continued his interest in the possible health consequences to the embryo and fetus following maternal intakes of radionuclides. With several collaborators he expanded his research to include a much larger range of radionuclides including fission products such as ⁸⁵Kr, ¹³¹I, ¹⁴⁴Ce, and ⁹⁰Sr; radon; uranium; and the transuranium elements including ²³⁹Pu, ¹⁴¹Am, ²⁵³Es, and ²⁴⁹Bk. This research has contributed significantly to the biokinetic and dosimetric models developed by the International Commission on Radiological Protection (ICRP) and National Council on Radiation Protection and Measurements (NCRP) for deriving dose coefficients for members of the public. Mel's most important contribution may be in identifying the many factors that influence the transfer of specific radionuclides across the placental membrane, the incorporation in the conceptus, the radiation doses received by the embryo/fetus, and the potential for early and long-term biological effects. His research showed that radionuclides have specific affinities and localize in characteristic organs and tissues of the feto-placental unit and of the embryo/fetus, influenced by the physical, chemical, and physiochemical state of radionuclides, the gestational stage, and maternal biokinetics. Mel's nearly 50 years of research have significantly increased our understanding of the risks to the embryo and fetus from maternal intakes of radionuclides and led to radiation protection practices directed to the reduction of these risks.

While pursuing studies on radionuclides, he collaborated with other scientists in some of the first research to apply ultrasound imaging to embryonic tissues. Mel's work on the prenatal effects of ultrasound helped to establish the safeness of this valuable clinical technique. With other scientists he examined the potential prenatal and postnatal effects of metals and slow-release system contraceptives used in intrauterine devices for birth control. He also investigated possible effects of nonionizing radiations including extremely low-frequency electromagnetic fields, microwaves, and dc-magnetic fields on the developing fetus. These studies were in response to concerns for potential health effects resulting from exposures to radiations from radar generators, microwave ovens, high-voltage electrical transmission lines, cell phones, etc. Then in the 1970s, during the Department of Energy's push to explore alternative energy sources, Mel conducted developmental and teratogenic studies on high-temperature-boiling liquids derived from coal liquefaction processes. He participated with other scientists in studies of a wide range of industrial chemicals, his emphasis always being on possible embryo toxicity.

Mel was extremely generous in sharing his expertise with others, but he remained focused on the developmental effects of radionuclides and improving radiation protection for members of the public. He was a charter member of the Health Physics Society (HPS), which honored him with Fellow membership. The Columbia Chapter of the HPS also honored him with Lifetime membership. He was a Fellow of the American Association for the Advancement of Science and the American Institute of Ultrasound. He was a member of the American Society for Investigative Pathology, Radiation Research Society, Society of Toxicology, and Teratology Society. He was actively involved in outreach and public educational efforts of regional professional organizations.

His expertise was recognized by his being asked to serve on numerous committees and panels, such as those of the National Academy of Sciences-National Research Council, Federal Food and Drug Administration, American Institute of Ultrasound in Medicine, Organisation for Economic Co-operation and Development Nuclear Energy Agency, and Committee on Interagency Radiation Research and Policy Coordination. Mel chaired the committee of the NCRP that authored NCRP Report 128, “Radionuclide Exposure of the Embryo/Fetus,” issued in 1998. He was a consulting member of the ICRP task group that prepared ICRP Publication 88, “Doses to the Embryo and Fetus from Intakes of Radionuclides by the Mother,” issued in 2002.

Mel epitomized the successful research team leader. He was generous with his knowledge and generous in sharing credit. He was skilled in experimental design and wise in bringing in outside expertise when needed. His easy-going manner gained him respect, admiration and, perhaps most important, for a research team, cooperation. He recognized the importance of making the results of his research available to sponsors and the public by publishing frequently in the peer-reviewed literature.

Mel was a true scholar, had a great sense of humor, was a good storyteller, was modest about his accomplishments, and set an example for all of us in his dealing with a series of health problems in the last few years. His hobbies included furniture making and photography and recently he had been growing gourds to make Southwest Indian-style rattles. He was an avid reader. With his family he enjoyed frequent visits to their vacation home at Seal Rocks on the Oregon coast. Mel was an active member of the Trinity United Church of Christ in Richland.

Mel is greatly missed by his wife Shirley, two sons, one daughter, and seven grandchildren. He is also missed by his many friends and colleagues, including a few of us who shared an occasional evening of “very low stakes” poker with him.