1. Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwado-kita, Komae, Tokyo 201-8511, Japan
2. Clinical Department, Southern Urals Biophysics Institute (SUBI), Ozyorskoe Shosse 19, Ozyorsk Chelyabinsk Region, 456780, Ozersk, Russia
3. Radiation Epidemiology Branch, National Cancer Institute (NCI), National Institutes of Health (NIH), 9609 Medical Center Drive, MSC 9778, Bethesda, MD 20892-9778, USA