Fukushima Radiation Exposure Far Less Than Feared
In the months following the Fukushima Daiichi nuclear accident, there has been much speculation about the amount of radiation exposure received by people who lived near the plant. Many press reports left readers with the impression that the members of the general public had been exposed to extremely high amounts of radiation. One notable example, “Japan Held Nuclear Data, Leaving Evacuees in Peril” by Martin Fackler and Norimitsu Onishi of the New York Times, described bureaucrats’ delayed release of radiation forecasting information as an act that would kill people:
“From the 12th to the 15th we were in a location with one of the highest levels of radiation,” said Tamotsu Baba, the mayor of Namie, which is about five miles from the nuclear plant. He and thousands from Namie now live in temporary housing in another town, Nihonmatsu. “We are extremely worried about internal exposure to radiation.”
The withholding of information, he said, was akin to “murder.”
Were residents of the evacuation zone directly exposed to murderous levels of radiation?
Subsequent studies have found that the direct exposure higher than normal, but not at a dangerous level. As NHK reports:
On Tuesday, the prefecture released the results for 1,727 people in Namie Town, Iitate Village and a district in Kawamata Town. The municipalities are 10 to 50 kilometers from the plant.
Fukushima says 1,675, or 97 percent, of the people are thought to have been exposed to less than 5 millisieverts of radiation. 1,084 people are thought to have been exposed to less than one millisievert — the government’s safety limit for one year.
Nine people are thought to have been exposed to 10 millisieverts or more. Five of them are nuclear plant workers, among whom the highest level was 37 millisieverts. Of other 4, one who repeatedly visited an evacuation zone was exposed to 14 millisieverts.
Fukushima Medical University Vice President Shunichi Yamashita says the results show that exposure levels of most people were lower than a standard that would require evacuation, with extremely low health impact.
That means that none of the people are thought to have been exposed to anything close to the 100 millisieverts, which is the minimum level of radiation exposure which is found to cause a statistically higher chance of developing cancer.
In related news, Dokkyo Medical University has been conducting tests with WBC scanners to determine the internal radiation exposure of people in the town of Nihonmatsu. Of the 467 people examined, only 81 were confirmed to have detectable amounts of cesium in their bodies. However, the amounts detected were far below dangerous levels, and would apparently have resulted in a cumulative exposure of under 1 millisievert.