Oregon State University

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Understanding Ionizing Radiation Carcinogenesis

Prof. Otto G. Raabe, Ph.D.

Wednesday, March 6, 2013 4:00 PM - 5:00 PM

 Prof. Raabe Professor Emeritus of Veterinary Molecular Biosciences and of Environmental Engineering at the University of California, Davis, where he has taught and conducted scientific research since 1976 in the fields of Radiation Biology andBiophysics, Airborne Particle Science, and Inhalation Toxicology.Also, he has been a board-certified Health Physicist (CHP) since1970 and a member of the Health Physics Society for over 50years.  

Abstract of Prof. Raabe's seminar:   

The current understanding of ionizing radiation carcinogenesis is informed by epidemiological studies of human populations exposed to elevated levels of ionizing radiation and controlled studies utilizing laboratory animals. In this presentation the ionizing radiation dose-response relationships for internally deposited radionuclides are reviewed using data from humans exposed to 226Ra and 228Ra and laboratory animal studies with alpha-emitters 226Ra, 238Pu, 239Pu, and 241Am and beta-emitters 90Sr, 91Y and 144Ce. Intake routes included ingestion, inhalation, and injection. The lifetime effects are best described by three-dimensional average-doserate/time/response surfaces that compete with other causes of death during an individual's lifetime. Protracted exposures induce cancer with a latency that depends on the lifetime average dose-rate of exposure to the target organ. At low dose rates the latent period may exceed the natural lifespan leading to a lifetime virtual threshold for cancer induction. These results are contrasted with the linear no-threshold hypothesis of ionizing radiation carcinogenesis based on the Japanese atomic bomb survivor studies. The findings have important implications with respect to peaceful uses of nuclear technology, medical procedures utilizing ionizing radiation,and safety standards for human exposures to ionizing radiation.


Radiation Center (campus map)
C 104
Casey Mills
541-737-2644
casey.mills at oregonstate.edu
Nuclear Engineering