Challenges and perspectives for internal radiation exposure examinations using the whole-body counting system following the Fukushima Daiichi nuclear power plant accident.

Radiation protection is a fundamental component of public health crisis management. Following the Fukushima Daiichi nuclear power plant (FDNPP) accident, relevant authorities have conducted internal radiation exposure examinations (IREEs) for residents for more than 15 years as part of ongoing public health response efforts. This report identifies three major challenges in evaluating the continued implementation of IREEs: (i) determining why IREEs have been sustained despite the extremely low proportion of residents with internal radiation exposure >1 mSv; (ii) examining how large-scale IREEs using whole-body counting systems have been implemented in practice; and (iii) evaluating how stakeholder engagement in radiation risk communication has contributed to both safety and security in Fukushima. These challenges and perspectives encompass numerous "Lessons learned from Fukushima." Three key perspectives were identified: (i) improving understanding of residents' perceptions of IREEs and identifying an appropriate balance between service provision and community demand to ensure equitable access; (ii) promoting the sustainable implementation of IREEs, strengthening preparedness for future nuclear disasters, and preserving Fukushima's long-term experience; and (iii) clarifying the current status and effectiveness of radiation risk communication associated with IREEs. To address these issues, a new initiative, the "Establishing Resident-Centered Implementation Policies for Internal Radiation Exposure Examinations" (RECIPEx) project, was launched in Japan from April 2025 to March 2028. The RECIPEx project is expected to provide a practical framework for integrating protection against internal radiation exposure into disaster preparedness strategies, thereby strengthening health management systems through the application of "Lessons learned from Fukushima."