Dr. Ohtsura Niwa was a graduate student in radiation biology at Kyoto University and in biophysics at Stanford University, where he earned a PhD in 1975. Starting his post-graduate career at Kyoto University Medical School in 1975, he moved to Hiroshima University in 1984, to Kyoto University Radiation Biology Centre in 1997, and to Japan’s National Institute of Radiological Sciences in 2007.
His research interest has been the molecular mechanisms of untargeted mutagenesis and their implications in somatic and heritable effects of radiation. In the early 1980s, he discovered that radiation can induce endogenous retroviruses in mice by de-methylation, whereupon they integrate into new sites in the genome to induce leukemia in some cases. His work includes mutations of maternally inherited minisatellite sequences in F1 mice conceived with irradiated spermatozoa, demonstrating the untargeted nature of mutation induction in these unstable sequence motifs.
Professor Niwa promoted radiation biology as a specialty by serving as president of the International Association of Radiation Research from 2007 to 2011. He moved to Fukushima Medical University after the Fukushima nuclear accident to serve as Professor and Chief Scientific Officer in the Radiation Medical Science Center’s Office of International Cooperation. Making the whole prefecture his campus, he has greatly advanced the understanding radiation risks among Fukushima residents. In June 2015, he was elected Chairman and Representative Director of the Radiation Effects Research Foundation in Hiroshima. Further information is available at: http://www.rerf.jp/intro/index_e.html He is a current member of ICRP Main Commission.