1 Department of Environmental Health, National Institute of Public Health, 351-0197, Wako, Japan.
2 Hiroshima High-Precision Radiotherapy Cancer Center, 732-0057, Hiroshima, Japan; Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 734-8551, Hiroshima, Japan. Electronic address: ozawa@hiprac.jp.