The government on Monday told Fukushima, Ibaraki, Tochigi and Gunma prefectures to suspend shipping of spinach and kakina, a locally produced leaf vegetable, following the detection of radioactive substances at levels above the provisional limits under the Food Sanitation Law. It also told Fukushima Prefecture to suspend shipping of raw milk for a similar reason. The radioactive substances apparently came from Tokyo Electric Power Co.'s stricken Fukushima No. 1 nuclear power plant. The government the next day called on people to limit consumption of spinach, cabbage and a few other leaf vegetables from Fukushima Prefecture.

The government, which had ruled out a large-scale nuclear accident, had not set allowable limits for radioactive substances in farm products. The health ministry hurriedly established provisional limits and notified prefectural governments March 17.

Chief Cabinet Secretary Yukio Edano said that even if one continues to eat 1 kg of the spinach every day for a year, the accumulated radiation level will be one-fifth that of one computerized tomography scan. And if one consumed the milk at the national average amount for a year, the accumulated radiation level would be about the same as that of one CT scan, he said.