Department of Radiobiology and Hygiene Management

Professor: Ryuji Okazaki, MD, PhD

Assistant Professor: Masaoki Kohzaki, PhD



In April 2013, this laboratory was newly established at the Institute of Industrial Ecological Sciences. We will be involved in comprehensive occupational health measures for radiation workers in decommissioning of nuclear power plants and medical personnel involved. Appropriate implementation of work management, work environment management, health management, and worker education are important. We will train professional occupational health personnel who can provide appropriate guidance and implementation of these in the field. We will conduct epidemiological studies of the health effects of radiation workers, develop methods for assessing the biological effects of low-dose radiation exposure, and study basic radiation effects using cell and mouse experiments with molecular biology, biochemistry, and genetic methods.

In addition, we will provide education and practical activities for disaster responders including radiation disasters and Fukushima nuclear power plant workers.

Research outlines

1.Support and research of TEPCO Fukushima nuclear power plant workers

As the Fukushima nuclear power plant support team at the University of Occupational and Environmental Health, we continue to support workers in hygiene management and radiation education. We analyze TEPCO's health diagnosis data and conduct radiation anxiety surveys.


2.Study of the effects of low-dose radiation using mice and cultured cells

The radioadaptive response is the only scientific evaluation of low-dose radiation. We will analyze the long-term effects of low-dose radiation based on survival rate and cause of death. We will study the involvement of the p53 gene immunologically and molecularly biologically using p53 gene-modified mice that have been subcultured in our classroom. Furthermore, in order to elucidate the carcinogenic mechanism of radiation exposure, we will use the uniquely established radiation-sensitive tumor suppressor gene RecQL4 knock-in cells and use molecular biology, biochemistry, and genetic techniques.


3.Development of personal assessment of radiation sensitivity

 The legal radiation dose limit is the collective dose determined by epidemiological surveys, so it is not strictly an evaluation of individual radiation sensitivity. We are considering a study to evaluate the radiosensitivity of individuals.


4.Development of education policy for radiation disasters and Fukushima nuclear workers

  We hold seminars on radiation disasters for first responders and create manuals for educational methods. We are also developing an educational program to reduce the anxiety of Fukushima nuclear power plant workers.


・Song Y, Okazaki R, Yoshida Y. Developmental and Comparative Immunology Senescence-associated secretory phenotype and activation of NF-κB in splenocytes of old mice exposed to irradiation at a young age. Developmental and Comparative Immunology. in press. 2021.

・Hayashi T, Mafune K, Matsuda N, Hasegawa A, Kato T, Kanda R, Shimada Y, Satoh K, Mori K, Tateishi S, Kohzaki M, Okazaki R. Questionnaire Survey of Fukushima Daiichi Nuclear Power Plant Workers in 2016 on Knowledge and Anxiety About Radiation. J UOEH. 42(4):339-346, 2020.

・Mori K, Tateishi S, Kubo T, Kobayashi Y, Hiraoka K, Kawashita F, Hayashi T, Kiyomoto Y, Kobashi M, Fukai K, Tahara H, Okazaki R, Ogami A, Igari K, Suzuki K, Kikuchi H, Sakai K, Yoshikawa T, Fujino Y. Assessing the effect of mandatory progress reporting on treatment requirements identified during health examinations at the Fukushima Daiichi Nuclear Power Plant: A time series analysis, J Occup Health. 62(1) : e12111, 2020.

・Kohzaki M, Ootsuyama A, Lue Sun, Moritake T, Okazaki R. Human RECQL4 represses the RAD52-mediated single-strand annealing pathway after ionizing radiation or cisplatin treatment. Int. J. Cancer: 146(11), 3098–3113 , 2020., 2020.

・Sun L, Inaba Y, Sato KHirayama A, Tsuboi K,  Okazaki R, Chida K, Moritake T. Dose-dependent decrease in anti-oxidant capacity of whole blood after irradiation: A novel potential marker for biodosimetry. Sci Rep. 8 (1): 7425, 2018. doi: 10.1038/s41598-018-25650-y.

・Mori K, Tateishi S, Kubo T, Kobayashi Y, Hiraoka K, Kawashita F, Hayashi T, Kiyomoto Y, Kobashi M, Fukai K, Tahara H, Okazaki R, Ogami A, Igari K, Suzuki K, Kikuchi H, Sakai K. Continuous Improvement of Fitness for Duty Management Programs for Workers Engaging in Stabilizing and Decommissioning Work at the Fukushima Daiichi Nuclear Power Plant, J Occup Health, 60(2):196-201. 2018 doi: 10.1539/joh.17-0150-CS.

・Okazaki R, Ohga K, Yoko-o M, Kohzaki M. A Survey about the Radiation Effects and A Health Survey of Fukushima Inhabitants after the Fukushima Daiichi Nuclear Power Plant Accident, J UOEH. 39(4):277-290, 2017.

・Morota K, Moritake T , Sun L , Ishihara T, Kuma N, Murata S, Yamada T, Okazaki R. Collection of DICOM RDSR (Digital Imaging and Communication in Medicine, Radiation Dose Structured Report) Information Aimed at Reducing Patient Exposure Dose. J UOEH. 38(4):335-343, 2016.

・Ohguri T, Kunugita N, Yahara K, Imada H, Uemura H, Shinya N, Youjirou G, Takashi C, Okazaki R,

    Ootsuyama A, Korogi Y. Efficacy of hyperbaric oxygen therapy combined with mild hyperthermia for

    improving the anti-tumour effects of carboplatin. Int J Hyperthermia. 31(6):643-648, 2015.

・Kohzaki M, Ootsuyama A, Moritake T, Abe T, Kubo T, Okazaki R. What have we learned from a

    questionnaire survey of citizens and doctors both inside and outside Fukushima? –Survey comparison

    between 2011 and 2013-. J Radiol Prot. 35(1):N1-N17, 2015.

・Mori K, Tateishi S, Kubo T, Okazaki R, Suzuki K, Kobayashi Y, Hiraoka K, Hayashi T, Takeda M, Kiyomoto Y,

    Kawashita F, Yoshikawa T, Sakai K, Transition of Occupational Health Issues Associated With Stabilization

    and Decommissioning of the Nuclear Reactors in the Fukushima Daiichi Nuclear Power Plant Through 2013,

    J OCCUP ENVIRON MED 56(11):1145-1152, 2014.

・Okazaki R, Ootsuyama A.p53-dependent delayed effects of radiation vary according to time of irradiation of

    p53(+/-)mice. Journal of Radiation Research, 55(1):25-31, 2014.

・Mori K, Tateishi, S Hiraoka, K, Kubo T, Okazaki R, Suzuki K, Kobayashi Y, Kohno K. How Occupational

    Health Can Contribute at a Disaster and What Should Prepare for the Future? -Lessons Learned through

    Support Activities of a Medical School at the Fukushima Daiichi Nuclear Power Plant in Summer 2011.

    Journal of Occupational Health 55(1):6-10, 2013.

・Okazaki R.Fukushima is not Chernobyl - The prognosis for Fukushima and the importance of education

    about radiation -, J UOEH 34 Supple:31-33, 2012.

・Okazaki R, Ootsuyama A, Yoshida Y, Norimura T, Molecular Biology International, Establishment of

    methylation-specific PCR for the mouse p53 gene. vol. 2011, Article ID 938435, 4 pages, 2011.