Medical Management of the Consequences of the Fukushima Nuclear Plant Incident

Makoto Akashi, M.D., Ph.D.
Executive Director, National Institute of Radiological Sciences (NIRS), Chiba, Japan

Abstract

An earthquake named The Great East Japan Earthquake measuring 9.0 on the Richter scale struck the northeast coast of the Honshu Island in Japan at 14:46 on 11 March 2011, triggering a tsunami with over 10 meter-high waves hitting the area. The earthquake was followed by sustained numerous aftershocks. The earthquake and aftershocks left more than 15,700 people dead and almost 4,500 missing. The earthquake affected the Fukushima nuclear power plants (NPPs) of Tokyo Electric Power Company (TEPCO) and caused serious damages to NPPs, resulting in a large amount of radioactive materials being released into the environment. Damage was caused to the cooling systems of the NPPs, whereas they automatically shut down after the earthquake. The trouble in the cooling systems led to hydrogen explosions and core melt-down. The major nuclides released on land were I-131, Cs-134 and Cs-137. The deposition of these radioactive materials on land resulted in a high ambient dose of radiation around the NPP, especially within a 20 km radius. Therefore, almost 170,000 people had to evacuate or stay indoors. This earthquake also affected infrastructures such as the monitoring system for radiation as well as NPPs and the telecommunications system. We dispatched our Radiation Emergency Medical Assistance Team (REMAT) to the local headquarters located 5 km from the NPPs almost 17 hours after the earthquake. However, the local headquarters did not function, since community lifelines such as water supply and electricity were severely damaged by the earthquake and tsunami. Furthermore, the local hospital system including radiation emergency medicine was dysfunctional. Fortunately, on the other hand, there have been no workers at NPPs or residents at the site who required treatment from the viewpoint of radiation exposure. We have learned from this disaster that the potential of damage to the monitoring and/or calculation system for radiation as well as lifelines in case of an earthquake should be taken into account, and a scenario including an impaired monitoring system for radiation is important for the drill of nuclear disasters. There is urgent need for a "combined disaster" strategy, which should be emphasized for current disaster planning and response.