Tokyo is warned on fallout in tap water

Radioactivity levels declared unsafe for babies

TOKYO — Radioactive iodine detected in Tokyo’s water supply prompted Japanese authorities yesterday to warn that infants in Tokyo and surrounding areas should not be given tap water to drink, adding to the anxiety about public safety posed by Japan’s unfolding nuclear crisis.

Ei Yoshida, head of water purification for the Tokyo water department, said at a televised news conference that infants in Tokyo and surrounding areas should not drink tap water. He said iodine-131 had been detected in water samples at a level of 210 becquerels per liter, about a quart. The recommended limit for infants is 100 becquerels per liter. For adults, the recommended limit is 300 becquerels. (The measurement unit is named for Henri Becquerel, one of the discoverers of radioactivity.)

The announcement added to the growing anxiety about public safety posed by the Fukushima Daiichi Nuclear Power Station, which was severely damaged by the March 11 earthquake and tsunami, and it prompted a run on bottled water at stores in Tokyo.

Prime Minister Naoto Kan said earlier yesterday that the public should avoid 11 types of vegetables grown near the power station because of contamination, according to the Japanese news media.

The Health Ministry said in a statement that it was unlikely that there would be negative consequences to infants who did drink the water, but that it should be avoided if possible and not be used to make infant formula. The warning applied to the 23 wards of Tokyo and the towns of Mitaka, Tama, Musashino, Machidam, and Inagi to the west of the city.

“It’s unfortunate, but the radiation is clearly being carried on the air from the Fukushima plant,’’ said Yukio Edano, the chief Cabinet secretary. “Because it’s raining, it’s possible that a lot of places will be affected. Even if people consume the water a few times, there should be no long-term ill effects.’’ There has been frequent rain in recent days and the watershed for Tokyo’s tap water lies almost entirely to the north and northeast of the city; the nuclear plant is about 140 miles to the north.

The Japanese daily Asahi Shimbun cited the Health Ministry as saying that drinking the water would hurt neither a pregnant woman nor her fetus, and that it was safe for bathing and other everyday activities.

But specialists say that pregnant women, nursing mothers, and fetuses, and children, face the greatest danger from radioactive iodine, which is taken in by the thyroid gland and can cause thyroid cancer. Children are at much higher risk than adults because they are growing and their thyroid glands are more active and in need of iodine. In addition, the gland is smaller in children than in adults, so there is less tissue to share the radiation, and a given amount of iodine-131 will deliver a higher dose of radiation to the thyroid and potentially do more harm in a child.Continued...

The compound potassium iodide can protect the thyroid by saturating it with normal iodine so it will have no need to soak up the radioactive form. People in Japan have been advised to take it. Scientists say that if it is in short supply and must be rationed, the pills should go first to pregnant women and children.

After the announcement yesterday, the shelves at the Lawson’s convenience store in the Tsukiji neighborhood of central Tokyo were about half-stocked with water. But a clerk said he had just restocked them an hour before.

“People came in and cleared us out in the first hour after the announcement,’’ he said, saying he didn’t want to be identified because he didn’t want to anger his boss. “They were taking 20 or 30 bottles at a time.’’

With water disappearing from the shelves, the Tokyo city government acted to calm fears, saying it would begin distributing 240,000 bottles of water today to families with children younger than 1 year, the broadcaster NHK reported. There are about 80,000 such children in the affected zone, NHK said.

The spread of at least a small amount of radiation is inevitable, considering the steam that is generated as emergency workers spray water on damaged reactors and cooling pools at the Fukushima complex. Government and power company officials were nonetheless expressing growing optimism that the crisis was closer to being brought under control.

But in a new problem at the plant, the cooling system for the No. 5 reactor stopped working yesterday afternoon, said Hiro Hasegawa, a spokesman for the Tokyo Electric Power Co., which operates the plant.

“When we switched from the temporary pump, it automatically switched off,’’ he said. “We’ll try again with a new pump in the morning.’’

Of the six reactors at the Fukushima Daiichi facility, only the No. 5 and No. 6 units were considered to be under control. They, along with No. 4, were offline before the quake and, while they have pools of spent fuel rods like the other reactors, they have been of less concern.

All of the facilities now have electrical power, a crucial step toward getting cooling systems restarted.

Officials said earlier yesterday they hoped to have the cooling pumps at the No. 3 and No. 4 units operating by as early as today. They had been planning to test reactor No. 3’s cooling system later yesterday. That reactor is considered one of the most dangerous because of its fuel — mixed oxides, which contains a mixture of uranium and plutonium and can produce a more dangerous radioactive plume if scattered by fire or explosions.

But the effort was set back when the No. 3 facility began belching black smoke late in the afternoon, leading Tokyo Electric to evacuate workers from the area. No flames were visible and the cause of the smoke was unknown, the company said. Later it said the smoke had stopped after about an hour.

Water also was sprayed on the No. 1 and No. 2 units yesterday.

Rebuilding after the 9.0-magnitude quake and tsunami, which ravaged the northeastern coast of the main Japanese island of Honshu, will cost up to $309 billion, Kan’s office said yesterday. The World Bank, citing private estimates, said on Monday that the figure could reach $235 billion. The economic cost of the disaster has hit Tokyo Electric, which is in negotiations with its bankers for loans of up to $24 billion, according to a person with direct knowledge of the situation who asked not to be identified.

The Associated Press reported yesterday that the official death toll from the disaster had been raised to more than 9,500 with more than 16,000 people missing, although officials said there could be overlap between the figures.