Introduction
The health impact on local residents following a nuclear disaster extends beyond radiation exposure, encompassing diverse effects related to lifestyle and changes in the social environment, with long-term implications observed across multiple aspects of life. In affected areas, the number of individuals certified for long-term care rises, leading to an increase in long-term care insurance expenditure.Reference Morita, Leppold and Tsubokura1
Rising public expenditure on long-term care represents one of the most significant challenges faced by aging societies and constitutes a major public health concern. However, medium-to-long-term trends in long-term care insurance expenditure following the lifting of evacuation orders after a nuclear disaster remain unclear. This could lay the groundwork for creating a more resilient health and welfare system in preparation for future large-scale earthquakes.
Katsurao Village, located near the Fukushima Daiichi Nuclear Power Plant, experienced a marked increase in residents requiring long-term care. At one point, long-term care insurance premiums were the highest among all municipalities nationwide. Understanding the long-term care challenges faced by Katsurao Village will offer valuable insights into the sustained impact of disasters on care needs and contribute to the development of effective post-disaster long-term care strategies.
Thus, this study aimed to analyze medium-to-long-term changes in long-term care insurance expenditure in disaster-affected areas by examining the trends in Katsurao Village, with the goal of informing future disaster response and public health policy.
Materials and Methods
Katsurao Village is a small mountainous village located approximately 20-30 km from the Fukushima Daiichi Nuclear Power Plant. With a pre-disaster population of around 1,500 people, the entire village was evacuated following the nuclear disaster. Although evacuation orders were lifted for most of the village in 2016 and residents gradually returned, the registered population decreased to 1,239 as of November 2024, with only 468 people residing in the village. As of February 2024, the aging rate among village residents reached 45.6%.2
We analyzed data from the “Katsurao Village Long-term Care Insurance Business Status Report,” utilizing the village’s long-term care insurance expenditure and population aged 65 years and over from 2010 to 2023. Long-term care insurance refers to the remuneration paid by the government to a business operator for providing nursing care services to a person who requires nursing care or support. The analysis period spanned from April 2010 to March 2023. Per capita long-term care insurance expenditure was calculated and compared with the national average,3 and the results are presented graphically.
Per capita long-term care insurance expenditure was defined as Katsurao Village’s total long-term care insurance expenditure divided by the village’s population aged ≥65 years.2 This metric allows the evaluation of substantive changes in long-term care insurance expenditures and facilitates comparisons with other regions by controlling for population size.
The study was conducted with the approval of the ethics committee of Fukushima Medical University (November 22, 2024, approval number: 2022-054).
AI-assisted tools, such as ChatGPT and OpenAI, were only used for language editing and formatting support. No AI-generated content was used to create, interpret, or analyze scientific data. The authors reviewed, modified, and verified all content and take full responsibility for the final manuscript.
Results
From the annual long-term care insurance expenditure data for Katsurao Village, the changes in per capita long-term care insurance expenditure for older residents before and after the disaster were calculated (Figure 1).

Figure 1. Trends in per capita long-term care insurance expenditures in Katsurao Village and nationwide, and Katsurao Village’s aging rate.
Compared to pre-disaster levels in 2010, when evacuation orders were largely lifted, in 2016, the average long-term care insurance expenditure increased by 2.85 times, reaching its peak. The number of individuals certified for long-term care increased from 100 in 2010 to 159 in 2016 before declining to 108 in 2023. While the national average remained relatively stable, Katsurao Village’s per capita long-term care insurance expenditure in 2016 reached JPY 562,970, approximately three times higher than the 2010 figure of JPY 197,461. This expenditure has gradually decreased since its peak in 2016 and has gradually declined, with a further decrease of approximately JPY 50,000 by 2020. However, it remained elevated at JPY 415,884 in 2023, which was still significantly higher than the pre-disaster levels.
Discussion
This study revealed that total long-term care insurance expenditure increased compared to 2010 levels and remained consistently high over the long term. This study revealed that total expenditures under the long-term care insurance system increased 2.85-fold in just six years, from 2010 (before the earthquake) to 2016. These expenditures have remained high over the long term. Many older residents who did not require long-term care before the nuclear accident may have become frail and were subsequently certified for care because of the sudden lifestyle changes associated with evacuation.Reference Tsubota-Utsugi, Sasaki and Suzuki4 Analysis of regional variations shows that even 6 years after the nuclear accident, long-term care certification rates in 15 cities within Fukushima Prefecture that suffered particularly severe damage remained higher than those in neighboring municipalities.Reference Inoue and Jeong5, Reference Tomata, Kakizaki and Suzuki6 Therefore, early preventive measures are essential to minimize the increase in the number of individuals requiring long-term care following nuclear accidents.
Furthermore, our findings showed that the per-capita long-term care insurance expenditure initially increased but began to decline after the lifting of evacuation orders in 2016. The initial increase can be attributed to deteriorating physical and mental health conditions associated with evacuation life and reduced informal support due to family separation resulting from evacuation.Reference Sawano, Kambe and Seno7 The decrease in the per-capita long-term care insurance in 2020 may also be attributed in part to a decrease in the use of day care and short-stay services due to the spread of COVID-19. However, approximately five years after the nuclear accident, expenditures decreased because of the promotion of preventive care activities, the natural decline in the number of care recipients, and population decline. Meanwhile, the government continues to fully exempt national health insurance and long-term care insurance premiums as affected people support even after more than a decade, which may contribute to the continued utilization of long-term care services.Reference Morita, Leppold and Tsubokura1, Reference Morita, Nomura and Furutani8
These trends in long-term care insurance expenditures reflect the complex challenges faced by post-disaster communities. In particular, the low return rate after the lifting of the evacuation orders (37.8% as of November 2024) may hinder the reconstruction of community support systems for older adults in need of care. Moreover, the current aging rate of 45.6% suggests a further increase in future long-term care insurance expenditures.
Therefore, when long-term evacuation is anticipated following disasters, it is crucial to implement frailty prevention activities at evacuation sites at an early stage. Furthermore, comprehensive measures are required, including support for community reconstruction and the development of evacuation plans that minimize family separation. Additionally, support measures, such as insurance premium exemptions, require careful evaluation of their effectiveness and long-term impact.
A limitation of this study is that the data were collected from only one village. This focus on a specific setting may introduce bias related to local cultural or environmental factors, thereby limiting the generalizability of our findings to other populations. Second, there was no data on relocated residents who moved their resident registrations to other areas except Katsurao Village. Our survey pertains solely to registered residents of Katsurao Village. Consequently, it did not include individuals who were Katsurao residents at the time of the disaster but later relocated to other villages. Therefore, it cannot be said that the subsequent circumstances of all disaster victims were tracked. Those who transferred their resident registration included households with children and individuals who utilized services at evacuation centers and subsequently settled permanently.
Conclusions
This study examined the long-term impact of post-nuclear accident evacuation on long-term care insurance expenditures. These expenditures remained elevated compared to pre-accident levels, even after evacuation orders were lifted, suggesting the prolonged effects of the disaster on care needs. The findings highlight the importance of frailty prevention in areas where evacuation may occur during future disasters. Furthermore, they suggest the necessity for continued preventive care measures after the lifting of the evacuation orders. Immediately after a disaster, it is important to provide support not only from local governments but also through cooperation with external organizations.Reference Zhao, Moriyama and Ito9
Data availability statement
None.
Author contribution
S.L. and N.I. conducted the data analysis; S.L., N.I., N.M., T.A., and M.T. drafted the manuscript; N.M., H.S., T.A., Y.K., and M.T. revised the manuscript; and N.I. and M.T. supervised the study. All authors have read and agreed to the published version of the manuscript.
Funding statement
This study was supported by the JSPS KAKENHI (grant number MO22K11233) and the Research Project on the Health Effects of Radiation organized by the Ministry of the Environment, Japan.
Consent for Publication
All the authors approved the publication of the article.
Competing interests
None.
Ethical standard
The study was approved by the Ethics Review Committee of Fukushima Medical University (Fukushima Medical University Ethics Review Committee, approval number: 2022-054) on November 22, 2024. All procedures were conducted in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
