1. Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences (NIRS) Chiba, Japan;
2. Department of Urology and Renal Transplantation, Yokohama City University Medical Center, Yokohama, Japan;
3. Division of Radiological Sciences, Faculty of Health Sciences, Tokyo Metropolitan University, Tokyo, Japan;
4. Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan; and
5. Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan