24 Septembre 2015
September 24, 2015
The sudden evacuation of elderly nursing home residents with long-standing ailments or disabilities after the Fukushima No. 1 Nuclear Power Plant disaster was more harmful to their health than radiation exposure had they remained at the homes, suggests a new study.
Researchers looked at 191 residents and 184 employees at three special care elderly nursing homes in Minamisoma, Fukushima Prefecture, within 20 to 30 kilometers of the stricken Fukushima plant.
The residents were evacuated to other municipalities around 10 days after the disaster. Researchers compared data on their deaths afterwards to a hypothetical situation where they stayed at the homes and faced no added risks to their health besides radiation exposure.
The researchers determined that the evacuation caused a combined loss of 11,000 days to the lifespans of the evacuated residents. A possible reason, they say, is a drop in the level of care due to the sudden evacuation. On the other hand, if the residents had stayed at the homes for 100 days, the researchers estimated based on radiation exposure data from Hiroshima and Nagasaki atomic bombing survivors that the drop in lifespan would have been a combined 27 days, a difference of around 400 times.
Researchers also considered a case where non-evacuating residents were exposed to 100 millisieverts of radiation, an amount at which the International Commission on Radiological Protection says that health effects from radiation are highly likely to appear. Even in that case, the lost lifespan was a combined 5,800 days. In a case of 20 millisieverts the lost lifespan was 1,100 days. Both were less than what was estimated lost from the hasty evacuation.
Former University of Tokyo instructor Michio Murakami, one of the researchers, said, "It is important to plan evacuations of the elderly ahead of time to reduce risk factors, such as not making them feel a sudden change in their environment."
The research results were carried in the American science journal Plos One.