Before the residents were allowed to return this week, an extensive cleanup was undertaken in the Miyakoji district.
Even so, the radiation that remains at Miyakoji is still probably much higher than what it was before the accident, according to Kelly Classic, a health physicist for the Mayo Clinic in Rochester, Minnesota, and an expert on radiation exposure. She said that the most recent testing at Miyakoji showed a range between 0.1 and 0.5 microsieverts per hour. On an annual basis, that means that residents are exposed to as much as 4,380 microsieverts per year, which Classic said is about ten times the normal background radiation level for the area.
These levels are far below what it would take to cause immediate illness, but the risk of long-term exposure to low-level radiation is unclear.
Classic and other experts said they were concerned that returning residents might be exposed to levels of radioactivity higher than 0.5 microsieverts per hour if they drank water from local aquifers or ate vegetables and meat grown in the area. (See related, “Fukushima’s Radioactive Water Leak: What You Should Know.”) Surface measurements by government inspectors, who walked around with hand-held radiation meters, might not have detected contamination from such sources, Classic said.
Edwin Lyman, a physicist and a senior scientist for the Union of Concerned Scientists, said he was concerned that the Japanese government was reopening Miyakoji and other restricted areas before they were fully cleaned up, out of a desire to stop paying compensation to evacuees. According to Asahi Shimbun, the government’s Nuclear Damage Liability Facilitation Fund has lent Tokyo Electric Power Company (TEPCO), the utility that operated the stricken plant, 1.5 trillion yen ($14.63 billion) so far to pay compensation to people in restricted areas. Lifting the evacuation orders would hasten the end of those payments.
“People should not be forced to make a choice between losing their homes and not being compensated, and moving back to a region that’s still more radioactive than it was before the accident,” Lyman said.