The easing was a bid by the government to bring the country a step closer to normalcy after the March 11 quake and tsunami, which destroyed wide areas of Japan’s Pacific coast and set off the world’s worst nuclear disaster since Chernobyl. But with lingering fears over radiation levels — as well as slow progress in decontaminating towns and cities hit by radioactive plumes — a return to these areas is likely to be slow.
A 12-mile exclusion zone will remain in place around the nuclear power plant, Fukushima Daiichi, which the government is working to bring under control. The worst contaminated areas close to the plant are likely to remain uninhabitable for decades, government officials have acknowledged.
Still, the government decided Friday to lift evacuation advisories for five lesser-hit towns and cities just outside that radius. Radiation levels in those towns and cities were stable enough to warrant lifting the advisories, which affected about 59,000 people, officials said. About 30,000 of those people had already returned to the area as radiation fears eased.
But questions remain about whether radiation levels are low enough for all residents to return. On Friday morning, for example, the entrance to Minamisoma city’s main hospital measured 0.51 microsieverts per hour in radiation, according to numbers released daily by the city. A simple calculation would bring annual exposure at the level to almost 4,500 microsieverts, or 4.5 millisieverts a year, far above the annual limit of 1 millisievert for civilians that is recommended by the International Commission on Radiological Protection.
At an elementary school in the town of Naraha, also declared safe for residents to return, the measurement came to 0.77 microsieverts per hour, or 6.75 millisieverts a year at that level.
While experts say these levels are still low — the limit for radiation workers in the United States is 50 millisieverts per year, for example — little is known about the health effects of extended exposure to low-level radiation. Moreover, children and pregnant women are known to be especially sensitive to radiation. A sievert measures the effect of radiation on the human body.
Defending its decision, the government cited progress in bringing the Fukushima plant to a relatively stable condition. In one milestone on Thursday, the government said that temperatures in the plant’s three most damaged reactors had fallen below 100 degrees Celsius, an important step toward what experts call a stable “cold shutdown” of the facility.
Despite Friday’s easing, many shops, schools, hospitals and train lines in the affected area remain closed — either damaged in the tsunami or simply unable to open because of the lack of staff and supplies — hindering any quick return to normalcy.
“There are many challenges we must overcome so residents can safely return home,” said Prime Minister Yoshihiko Noda, promising to speed up a cleanup effort that is expected to cost tens of billions of dollars. “The government must unite and lead the way in decontamination and recovery efforts, so we can clear away any doubts evacuees may have about returning,” he said.
The central government’s slowness in aiding areas affected by the disaster has irked some residents, however. Katsunobu Sakurai, mayor of one of the cities cleared for rehabilitation, said that tireless efforts by city officials were behind any progress made in preparing for residents to return. Since early summer, the city, Minamisoma, has teamed up with researchers from Tokyo University to decontaminate kindergartens and elementary schools, digging up contaminated soil in school yards and scrubbing surfaces with brushes.
Many residents also worry that “hot spots” of high radiation still exist across the city, posing health risks. “We’re the ones who took the lead,” Mr. Sakurai told the public broadcaster, NHK. “Now we’d like more assistance from the country.”
There is also the question of where to dispose of the huge amounts of nuclear waste from the decontamination work. Lacking proper disposal or treatment facilities, cities and towns in the area are simply piling up radioactive soil and debris in fields and parking lots and even in corners of school playgrounds.
Goshi Hosono, the minister in charge of the nuclear disaster, said that the government would come up with new laws and measures to deal with radioactive waste by next month.