Tap water in Tokyo has tested more than twice the limits for radioactive iodine considered safe for infants, officials said today.
Levels at a downtown water treatment center that supplies much of the city’s tap water contained 210 becquerels per liter of iodine-131.
That’s more than twice the recommended limit of 100 becquerels per liter for infants.
Babies in Tokyo should not be given tap water although the level is not an immediate health risk for adults, officials said.
The news came after a day in which temperatures soared in the core of one of Japan’s quake-crippled nuclear reactors, sparking new meltdown concerns.
An executive of the power company said the core of reactor No. 1 had reached nearly 735 degrees — more than 150 degrees higher than its recommended operating temperature.
“We need to strive to bring that down a bit,” said Tokyo Electric Power Co.’s understated vice president, Sakae Muto. “We need more time. It’s too early to say that they are sufficiently stable.”
There was still more bad news:
* Workers had to be pulled from the plant’s No. 2 reactor because of high radiation levels. It was not immediately clear when they’d be allowed back.
* Two workers were injured trying to restore power to the plant’s critical cooling systems.
The power plant, battered by a tsunami after the March 11 quake, continued to spew radiation from an undetermined source, according to the International Atomic Energy Agency.
Radioactive particles from the battered plant found their way into the sea, raising concern that seafood, a staple for the country, may become tainted.
Five kinds of materials released by damaged fuel rods were detected in the sea, including iodine-131, which increases the risk of thyroid cancer.
Levels of that isotope were 127 times higher than normal in a sample of seawater, but radiation experts said that even those levels posed only a limited risk.
Seawater readings showed the much longer-lived cesium-134 was 25 times normal and cesium-137 was 17 times higher. Cobalt has also been detected.
Minuscule traces of radiation have been detected as far away as Iceland, officials said.
“You could swim in the water with these levels of iodine-131 and there shouldn’t be a problem,” said Don Higson, a Sydney-based fellow at the Australian Radiation Protection Society.
“The only risk might be if people eat seafood with these materials inside it, and this will be something the authorities will be paying careful attention to.”
Japanese officials have already detected levels of radioactive material beyond legal limits in broccoli and raw milk in areas near the Fukushima Daiichi plant.
And traces of radioactive material were found in drinking-water supplies as well as spinach in Fukushima.
The US said it will ban imports of dairy products and produce from the troubled areas.
Gregory Hartl, a spokesman for the World Health Organization, said “food-borne radiation will last longer than airborne radiation. Even smaller amounts of radiation in food could potentially be more dangerous because you ingest it.”
Prime Minister Naoto Kan ordered two prefectures near the plant to halt shipments of farm products.