Diabetes and psychological distress posed greater risks than model-inferred risk of radiation-induced cancer after the Fukushima disaster: An application of the loss of happy life expectancy indicator.

After disasters, direct deaths and secondary health effects, such as diabetes and psychological distress, can occur. After the 2011 Fukushima disaster, radiation exposure was extremely limited; however, secondary health effects increased significantly. It is critical to compare the magnitudes of these model-inferred risks to promote lifespan development and effective public health measures. Here, we used the loss of happy life expectancy (LHpLE) to compare the model-inferred risks associated with diabetes, psychological distress, and radiation-induced cancer after the disaster. Two questionnaire surveys were conducted among individuals 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 554 participants, respectively. Additionally, we calculated the LHpLE owing to these model-inferred risks. 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). In the population aged 40-74 years, the LHpLE due to model-inferred risks of radiation-induced cancer, diabetes, and psychological distress were 0.0013, 0.14, and 0.21 years, respectively. This suggests that the association of LHpLE with diabetes and psychological distress was over two orders of magnitude greater than that associated with model-inferred risk of radiation-induced cancer. Within 7 years following the disaster, LHpLE due to diabetes increased, highlighting that diabetes is an ongoing issue. Therefore, this novel indicator of the LHpLE can provide a foundation for promoting lifespan development and effective public health measures following disasters.