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Leonard Sagan BELLE Award

The Biological Effects of Low Level Exposures (BELLE) Advisory Committee announces that Dr. Sheldon Wolff, University of California, San Francisco and the Radiation Effects Research Foundation, Hiroshima, Japan is the recipient of the 1998 Leonard Sagan BELLE Award for outstanding scientific contributions providing important insights regarding the biological actions of chemicals and/or radiation at the low end of the dose-response curve.


Dr. Sheldon Wolff obtained his B.S. degree (Magna cum Laude) from Tufts College in 1950, an M.A. from Harvard in 1951, and his Ph.D. from Harvard in 1953. He then joined the staff of the Biology Division of the Oak Ridge National Laboratory. Dr. Wolff was the first to demonstrate the metabolic repair of damage to the genetic apparatus, the genes and chromosomes within the cell. In this work, he showed that the repair, or rejoining, of radiation-induced chromosome breaks was dependent upon metabolic processes and the synthesis of chemical bonds, rather than being a simple physical fusion of broken ends, as had hitherto been thought. This work, and his biochemical and biophysical studies on the kinetics of the induction and repair of genetic damage, changed the way researchers thought about chromosomal damage and was instrumental in Dr. Wolff becoming known as one of the world's leading cytogeneticists. In 1966 he was recruited to the faculty of the University of California at San Francisco (UCSF) as Professor of Cytogenetics and Radiology with a joint appointment in the Department of Anatomy where he continued his pioneering research into the mechanisms of chromosome damage and repair until 1996.

Dr. Wolff's interest in chromosomes and how they react to chemical and physical insults never waned. During his tenure at UCSF he devised the methodology that allowed sister chromatid exchanges (SCEs) to become a standard cytogenetic tool. The extensive studies on the mechanisms and biological significance of SCEs by Wolff and his colleagues led to their use throughout the world as one of the most sensitive mammalian cell assay systems to detect the effects of mutagens and carcinogens. As a result of this work, three of Dr. Wolff's publications in this area have been honored as Citation Classics by the Institute for Scientific Information, which publishes Current Contents

More recently he turned his attention to the controversial area of radiation hormesis whereby low doses of radiation are reputedly beneficial. Dr. Wolff's work on the induction of chromosome aberrations in human lymphocytes has shown that extremely low doses of radiation do trigger the induction of new proteins that are involved in the repair of the molecular lesions that manifested as chromosome aberrations. Once induced, these repair enzymes can be effective in cells for up to three cell cycles, and cells “adapted” with a low dose of radiation or chemical, show much less damage after a subsequent exposure to a high dose of radiation, or even chemical mutagens, than observed in cells not pre-exposed (adapted) to the low doses. This phenomenon, termed the adaptive response to low doses of radiation, has now led to a worldwide explosion of research in this area not only with cellular systems, but also with whole animals to see if our current risk estimates of the effects of mutagens are appropriate. To date, there have been at least four international conferences that have been spawned by Dr. Wolff's work

During his tenure at Oak Ridge National Laboratory and UCSF, Dr. Wolff has mentored a large number of graduate students and postdoctoral fellows. Many of those individuals who spent part of their scientific careers in Dr. Wolff's laboratory are now leaders in different areas of radiation biology research, cytogenetics and environmental toxicology. His students and fellows have positions in industry, the government, and academia, and function to continue the legacy of high quality science and scientific judgment learnt in “the Wolff lab.”

His national and international reputation has led to his being continually called upon for scientific advice for the government, scientific societies, and scientific journals. In 1993 he was awarded the prestigious E.O. Lawrence Memorial Award from the United States government. Dr. Wolff served on the “Mammalian Genetics Study Section” and has been involved in a number of scientific peer review committees for the National Institute of Health and the National Cancer Institute. He has served on several committees of the National Academy of Sciences-National Research Council, and was a member of its Space Science Board and its first Safe Drinking Water Committee.

For an unprecedented nine years, he was Chairman of the United States Department of Energy's Health and Environmental Research Advisory Committee, and for three years was co-chair of the National Institute of Health/Department of Energy Joint Subcommittee on the Human Genome. He also was an advisor to the European Community's Coordinated Research Program on Low-Dose Radiation and Inducible Repair Phenomena, which was run by the United Nations through its International Atomic Energy Agency. In addition, he has been an Associate Editor, or on the Editorial Board, of 11 different scientific journals. Dr. Wolff has served as the President of the Environmental Mutagen Society (U.S.A.) and as Treasurer of the International Association of Environmental Mutagens. He was Chairman of the program committee of the XIII International Congress of Genetics, whereby he was responsible for the entire scientific organization of the Congress, and organized numerous other workshops and/or symposia presentations on SCE or low-dose radiation effects.

In addition to contributing heavily to University Service at UCSF, where he was the Director of the Laboratory of Radiobiology and Environmental Health, an Organized Research Unit of the Department of Energy, he also had been, and is, heavily involved in public service in the scientific arena.

Currently Dr. Wolff, who is Professor Emeritus at UCSF, is the Vice Chairman and Chief of Research of the Radiation Effects Research Foundation (RERF) in Hiroshima, Japan. RERF is the successor agency to the Atomic Bomb Casualty Commission in Hiroshima and Nagasaki, Japan.

William F. Morgan, Ph.D. Dept. of Radiation Oncology, University of California Tel: 415-476-3155, Fax: 415-476-0721


Nominations for the 1999 Leonard Sagan BELLE Award should include a two-page summary of the nominee and should be received by June 29, 1998 in the BELLE Office. The recipient will receive an honorarium and plaque and will provide a synopsis of their work for publication in the journal Human and Experimental Toxicology.

BELLE, which represents a cooperative activity of representatives of various federal agencies, private-sector companies and universities, was established in 1990 and is administered by the University of Massachusetts in Amherst under the direction of Professor Edward J. Calabrese.


BELLE Office Northeast Regional Environmental Public Health Center School of Public Health, University of Massachusetts Amherst, MA 01003. Telephone: 413-545-3164 Fax: 413-545-4692; Email:; Website: