Comparing the risks of diabetes, psychological distress, and radiation-induced cancer exposure after the Fukushima disaster using the loss of happy life expectancy

After disasters, direct deaths and secondary health effects, such as diabetes and psychological distress, can occur. It is critical to compare the magnitudes of these risks to promote effective public health measures. 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. 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. Additionally, we calculated the LHpLE owing to these 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 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 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 effective public health measures following disasters.