Nearly 40% of Self-Defense Forces troops, police officers and firefighters involved in evacuation operations right after the 2011 Fukushima nuclear crisis were exposed to radiation above the annual public limit of 1 millisievert, the government said Monday.
The Cabinet Office surveyed for the first time 2,967 personnel who assisted in evacuating residents living within a 20-kilometer radius of the Fukushima Daiichi nuclear complex as well as radiation cleanup and other activities from March 12 to 31, 2011.
The survey found that around 62% were exposed to radiation of less than 1 millisievert. But 38% were exposed to 1 millisievert or more, of whom 19% received 1 to 2 millisieverts and 5% received 5 to 10 millisieverts.
Daily radiation doses remained high until around March 15—the day the third reactor building suffered an explosion at the plant—and dropped below 0.1 millisievert from March 18.
The Cabinet Office revealed the data at a meeting to discuss ways to mitigate the radiation exposure of civilians helping others to evacuate in the event of a nuclear accident.
The government plans to set a 1-millisievert-limit for civilians assisting in evacuations such as bus drivers. But some bus drivers are reluctant to accept the proposal.
The maximum radiation dose for ordinary members of the public is set at 1 millisievert per year. The limit for workers at nuclear facilities is 100 millisieverts over five years and 50 millisieverts per year in normal times, but it is raised in emergencies.