A person who consumed the tainted food continuously for a year would take in the same amount of radiation as a single CT scan, Edano said. That's about 7 millisieverts or double what an average person in an industrialized country is exposed to in a year, according to the U.S. Food and Drug Administration.

Beyond Saturday's food safety announcement, there have been few indications of any immediate fallout from the nuclear crisis.

Airborne radiation levels around Japan have shown no signs of spiking drastically, according to measurements posted online Saturday by the nation's education and science ministry.

Most readings showed detectable but relatively small amounts of radiation. Even the two top readings in Mito (in Ibaraki prefecture) and Utsonomiya (in Toshigi prefecture) are well below what's considered dangerous to humans and had fallen in recent days.

Still, no one has said that authorities are in the clear. In fact, authorities acknowledged Friday that the situation is far more serious than they'd originally estimated.

" We sincerely apologize ... for causing such a great concern and nuisance," said a statement from Masataka Shimizu, the president of Tokyo Electric.

And the company's managing director, Akio Komori, broke down in a tears after leaving a news conference in Fukushima at which exposure levels were discussed.

Six members of the emergency crew at the plant have been exposed to more than 100 millisieverts of radiation per hour, the equivalent of getting 10 chest X-rays per hour, Tokyo Electric Power Company said.

The utility said the workers were exposed when trying to restore electricity to the stricken reactors in hopes of using the cooling systems again.

Tokyo Electric had raised the exposure level for emergency workers from its previous standard of 100 millisieverts per hour to 250 millisieverts.

People are naturally exposed to about 3 millisieverts of radiation a year. The International Commission on Radiological Protection recommends no more than 50 millisieverts exposure in a given year for nuclear rescue and recovery workers. It offers no restriction in a crisis when " the benefit to others clearly outweighs the rescuer's risk."

CNN's Yoko Wakatsuki, Stan Grant and Steven Jiang contributed to this report

Good News :)