Yukio Edano, the chief cabinet secretary, said more foods will be checked, but what's been discovered so far poses no immediate health risk. He said a person would have to drink the milk for a year to ingest as much radiation as in a CT scan. A year of the spinach would amount to about one-fifth of a CT scan.
"It's not like if you ate it right away you would be harmed," Edano told reporters in Tokyo as Japan's nuclear crisis entered its second week. "It would not be good to continue to eat it for some time."
Also worrisome were the traces of radioactive iodine detected in tap water in Tokyo, 220 kilometres from the overheating nuclear plant in Fukushima prefecture, and in several other prefectures, although again the government played down any safety concern.
The iodine in Fukushima tap water tested above safety limits on Thursday, the government said, but had fallen to within legal limits by Saturday.
First reports of tainted food, water
The food and water reports were the first since the March 11 quake and tsunami knocked out power to cooling systems at the Fukushima Daiichi nuclear complex. Four of the plant's six reactor units have experienced fires, explosions or partial meltdowns.
The contaminated milk was found on farms 30 kilometres from the plant, and the spinach was collected between 80 and 100 kilometres to the south, Edano said.
The government has banned sales and exports of food from the areas where the tainted food was found.
UN radiation tracking shows levels taken elsewhere in Japan, as well as in Russia and California, are minuscule, a diplomat with access to the readings said.
The quake and tsunami that ravaged Japan's northeastern coast knocked out backup cooling systems at the nuclear plant, which has been leaking radiation.
Emergency crews worked Saturday to restore electrical power to the plant so they can try to restart the systems that cool the nuclear reactors.
Tokyo Electric Power Co., the company trying to get the reactors under control, said it has managed to lay power lines to four units at Fukushima Daiichi.
By Sunday, the company said, it may have a line to the most dangerously hot unit, but there are no guarantees its cooling pumps will work after a week of explosions, the CBC's Curt Petrovich reported.
Spraying troubled plant
Emergency crews were working frantically Saturday to restore electrical power to the plant so they can try to restart the systems that cool the nuclear reactors.
Firefighters were water directly from the ocean Saturday into one of the most troubled areas of the nuclear complex - the cooling pool for used fuel rods at the plant's Unit 3. The rods are at risk of burning up and sending radioactive material into the environment.
The quake spawned a tsunami that ravaged Japan's northeastern coast, killing more than 7,200 people and knocking out backup cooling systems at the nuclear plant, which has been leaking radiation.
The tainted milk was found 30 kilometres from the plant, while the spinach was collected between 80 and 100 kilometres to the south, Edano told reporters in Tokyo.
Nuclear reactors at the Fukushima plant began overheating and leaking radiation into the atmosphere in the days after the quake and the subsequent tsunami overwhelmed its cooling systems.
Total Disaster and Chaos
Things not getting worse: government
The government admitted it was slow to respond to the nuclear troubles, which added another crisis on top of natural disasters, which officials estimate killed more than 10,000 people and displaced more than 400,000 others.
The complex is deeply troubled, Edano said Saturday, but it's not getting worse.
"The situation at the nuclear complex still remains unpredictable. But at least we are preventing things from deteriorating."
A fire truck with a high-pressure cannon was parked outside the plant's Unit 3, about 300 metres from the Pacific coast, and began shooting a stream of water nonstop into the pool for seven straight hours, said Kenji Kawasaki, a spokesman for the nuclear safety agency.
A separate pumping vehicle will keep the fire truck's water tank refilled. Because of high radiation levels, firefighters will only go to the truck every three hours when it needs to be refuelled.
Emergency workers are also funnelling water into the complex's most troubled reactors - Units 1, 2 and 3, officials said.
A power company official said holes had to punched in the roofs of the buildings housing Units 5 and 6, as workers tried to prevent dangerous buildups of hydrogen gas - a sign that temperatures continued to rise in those units' fuel storage pools.
Firefighters had started pumping water into Unit 5's pool, and the temperature had gone down, but a pump broke, delaying the refilling, the official said.
Meanwhile, Hidehiko Nishiyama of Japan's Nuclear and Industrial Safety Agency said backup power systems at the plant had been improperly protected, leaving them vulnerable to the tsunami that savaged the northeastern coast.
The failure of Fukushima's backup power systems, which were supposed to keep cooling systems going in the aftermath of the quake, let uranium fuel overheat and were a "main cause" of the crisis, Nishiyama said.
"I cannot say whether it was a human error, but we should examine the case closely," he told reporters.
A spokesman for Tokyo Electric Power Co., which owns and runs the plants, said that while the generators themselves were not directly exposed to the waves, some electrical support equipment was outside.
Find out more about the dangerous health effects radiation has on humans here.