I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. This study was funded by JSPS KAKENHI Grant Number JP17K20069, JP20H04354 and 'The Nippon Foundation - Osaka University Project for Infectious Disease Prevention.' Author Declarations The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Ozaki has received personal fees from Medical Network Systems and Kyowa Kirin Inc., outside the scope of the submitted work. Therefore, this novel indicator of the LHpLE can provide a foundation for promoting effective public health measures following disasters. Within 7 years following the disaster, LHpLE due to diabetes increased, highlighting that diabetes is an ongoing issue. This suggests that the association of LHpLE with diabetes and psychological distress was over two orders of magnitude greater than that associated with radiation-induced cancer. In the population aged 40–74 years, the LHpLE due to radiation-induced cancer, diabetes, and psychological distress were 0.0013, 0.14, and 0.21 years, respectively. Although no significant reduction was found in emotional happiness due to diabetes or breast cancer, a significant reduction occurred due to psychological distress (0.265 and 0.476 for males and females, respectively). Additionally, we calculated the LHpLE owing to these risks. Two questionnaire surveys were conducted on people affected by the disaster to investigate the potential associations between diabetes and psychological distress, as well as breast cancer and reduced emotional happiness, with 680 and 582 participants, respectively. In this study, we used the loss of happy life expectancy (LHpLE) to compare the risks associated with diabetes, psychological distress, and radiation-induced cancer after the 2011 Fukushima disaster. It is critical to compare the magnitudes of these risks to promote effective public health measures. After disasters, direct deaths and secondary health effects, such as diabetes and psychological distress, can occur.

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