1. Cabinet Office.Situation on ageing population in annual report on the ageing society: 2018 (summary). Accessed July 21 2022.https://www8.cao.go.jp/kourei/whitepaper/w‐2018/gaiyou/pdf/1s1s.pdf
2. The Ministry of Health Labour and Welfare.The situation concerning the nursing care. Accessed July 21 2022.https://www.mhlw.go.jp/content/12300000/000608284.pdf
3. World Health Organization.Health risk assessment from the nuclear accident after the 2011 great East Japan earthquake and tsunami based on a preliminary dose estimation. Accessed July 21 2022.https://apps.who.int/iris/bitstream/handle/10665/78373/WHO_HSE_PHE_2013.1_eng.pdf;sequence=1
4. United Nations Scientific Committee on the Effects of Atomic Radiation.UNSCEAR 2013 report. Volume I: Report to the General Assembly annex A: levels and effects of radiation exposure due to the nuclear accident after the 2011 great east‐Japan earthquake and tsunami.
5. Health effects of radiation and other health problems in the aftermath of nuclear accidents, with an emphasis on Fukushima