Nuclear radiation is the kind of thing that strikes fear in the hearts of just about everybody. So strong is this fear, however, that it may lead us to overlook more serious hazards associated with nuclear accidents. For example, a team of Japanese researchers report that evacuation following the Fukushima nuclear accident may have been much worse for Japanese citizen's health than nuclear radiation.
"Radiation doses ... and the consequent cancer risks, have been comprehensively evaluated," writes a team led by Michio Murakami, an associate professor in the department of health risk communication at Fukushima Medical University. "However, evacuation-related risks are also a major issue," they write, particularly for seniors and others who are already in poor health. Those individuals might not survive the mental and physical stresses associated with evacuation, such as being treated by doctors who may not be up to speed on each patient's needs.
Evacuation could be much worse than sitting tight for a few months.
The question is, could evacuation really pose a greater risk than radiation? For residents in three nursing homes in Minamisoma, roughly 25 kilometers from the accident site, the answer is a resounding yes, according to the researchers. In developing that conclusion, the team compared four hypothetical scenarios: a rapid evacuation, similar to those that occurred shortly after the accident; a delayed evacuation 90 days later, which would give officials time to plan post-evacuation patient care; and two scenarios in which nursing home workers and patients stayed put and were exposed to (relatively) low and high doses of radiation. For each scenario, the team estimated cancer risk based on radiation exposure around the nursing homes and at evacuation sites about 250 kilometers away. To estimate the impacts of evacuation, the team drew on actual mortality rates before and after the accident, both among residents of the three nursing homes and two others that were located farther from the nuclear reactor and didn't evacuate.
Putting the data together, the researchers found evacuation could be much worse than sitting tight for a few months. Assuming a rapid evacuation, the researchers estimated that nursing-home residents would lose about 11,000 days of their lives—roughly two months for each of the 191 evacuated residents—while staff wouldn't lose a day. In contrast, staff and residents would lose just a few hours off their lives due to radiation in the delayed scenario. Only in the high-dose, no-evacuation scenario was there comparable loss of life expectancy—around 5,800 days all told—suggesting that immediate evacuation wasn't necessarily the best option.
"Here, our intention is not to insist that the decisions made by nursing homes in the 2011 accident were inappropriate," especially given the uncertainty following the accident, the researchers write. But, they add, "[t]here needs to be serious deliberation as to whether to reduce evacuation-related risks or pursue protective actions other than evacuation."
Quick Studies is an award-winning series that sheds light on new research and discoveries that change the way we look at the world.