By ELAINE KURTENBACH and SHINO YUASA
TOKYO - Anxiety over Japan's food and water supplies soared following warnings about radiation leaking from Japan's tsunami-damaged nuclear power plant into Tokyo's tap water at levels unsafe for babies over the long term.
Residents cleared store shelves of bottled water after Tokyo Gov. Shintaro Ishihara said that levels of radioactive iodine in tap water were more than twice what is considered safe for babies. Officials begged those in the city to buy only what they need, saying hoarding could hurt the thousands of people without any water in areas devastated by the March 11 earthquake and tsunami.
"I've never seen anything like this," clerk Toru Kikutaka said, surveying the downtown Tokyo supermarket where the entire stock of bottled water sold out almost immediately after the news broke Wednesday, despite a limit of two, two-liter bottles per customer.
The unsettling new development affecting Japan's largest city, home to around 13 million people, added to growing fears over the nation's food supply.
Radiation from the Fukushima Dai-ichi nuclear plant has seeped into raw milk, seawater and 11 kinds of vegetables, including broccoli, cauliflower and turnips, from areas around the plant.
The U.S. Food and Drug Administration said it was halting imports of Japanese dairy and produce from the region near the facility. Hong Kong said it would require that Japan perform safety checks on meat, eggs and seafood before accepting those products, and Canada said it would upgrade controls on imports of Japanese food products by requiring documents verifying their safety.
Concerns also spread to Europe. In Iceland, officials said they measured trace amounts of radioactive iodine in the air but assured residents it was "less than a millionth" of what was found in European countries in the wake of the 1986 Chernobyl disaster.
The crisis already is emerging as the world's most expensive natural disaster on record, likely to cost up to $309 billion, according to a new government estimate. Police estimate that more than 18,000 people were killed.
The overall situation at the Fukushima plant 140 miles (220 kilometers) north of Tokyo remains of serious concern, the International Atomic Energy Agency said. The deposition of radioactive iodine and cesium varies across 10 prefectures on a day to day basis but "the trend is generally upward," said Graham Andrew, senior adviser to IAEA chief Yukiya Amano.
The Fukushimi Dai-ichi plant has been leaking radiation since the tsunami engulfed its crucial cooling systems, leading to explosions and fires in four of the facility's six reactors in the ensuing days.
Nuclear workers have struggled to stabilize and cool down the overheated plant.
Unit 3 has stopped belching black smoke, an official at Tokyo Electric Power Co. said Thursday, a day after a plume forced an evacuation of nuclear workers. However, white smoke was rising intermittently from two other units, spokesman Masateru Araki said.
As a precaution, officials have evacuated residents within 12 miles (20 kilometers) of the plant and advised those up to 19 miles (30 kilometers) away to stay indoors to minimize exposure.
And for the first time, chief Cabinet secretary Yukio Edano suggested that those downwind of the plant should stay indoors with the windows shut tight - even if just outside the zone.
In Tokyo, the municipal government planned Thursday to distribute 240,000 bottles of water to households with infants. They estimated 80,000 babies in the affected area, with each infant getting three bottles of 550 milliliters.
Officials said tap water showed elevated radiation levels: 210 becquerels of iodine-131 per liter of water - more than twice the recommended limit of 100 becquerels per liter for infants. Another measurement taken later at a different site showed the level was 190 becquerels per liter. The recommended limit for adults is 300 becquerels.
"It is really scary. It is like a vicious negative spiral from the nuclear disaster," said Etsuko Nomura, a mother of two children ages 2 and 5. "We have contaminated milk and vegetables, and now tap water in Tokyo, and I'm wondering what's next."
Infants are particularly vulnerable to radioactive iodine, which can cause thyroid cancer, experts say. The limits refer to sustained consumption rates, and officials urged calm, saying parents should stop giving the tap water to babies, but that it was no problem if the infants already had consumed small amounts.
They said the levels posed no immediate health risk for older children or adults.
Dr. Harold Swartz, a professor of radiology and medicine at Dartmouth Medical School in the U.S., said the radiation amounts being reported in the water are too low to pose any real risk, even to infants who are being fed water-based formula or to breast-fed infants whose mothers drink tap water.
Radioactive iodine is also short-lived, with a half-life of eight days - the length of time it takes for half of it to break down harmlessly.
Richard Wakeford, a public health radiologist at the University of Manchester in Britain, blamed the spike in radiation on a shift in winds from the nuclear plant toward Tokyo. He predicted lower levels in coming days.
Edano pleaded with shoppers to restrict purchases of bottled water to the bare necessity, urging them to think of tsunami victims in need.
"We have to consider Miyagi, where there is no drinking water at all," he said, referring to a stricken region. "Under these conditions, we would appreciate it if people would avoid buying more water than they need."
The latest data showed sharp increases in radioactivity levels in a range of vegetables. In an area about 25 miles (40 kilometers) northwest of the nuclear plant, levels for one locally grown leafy green called kukitachina measured 82 times the government limit for radioactive cesium and 11 times the limit for iodine.
With supplies of fuel and ice dwindling, officials have abandoned the traditional practice of cremation in favor of quick, simple burials. Some are interred in bare plywood caskets and others in blue plastic tarps, with no time to build proper coffins. The bodies will be dug up and cremated once crematoriums catch up with the glut, officials assured families.
In Higashimatsushima in Miyagi prefecture, soldiers saluting as they lowered bodies into freshly dug graves. Two young girls wept inconsolably, hugged tightly by their father.
"I hope their spirits will rest in peace here at this temporary place," said mourner Katsuko Oguni, 42.
Masaru Yamagata, a Higashimatsushima official, said the crematorium cannot keep up with demand.
"Giving the grieving families coffins is the most we can do right now," Yamagata said. "Every day, more dead bodies are found, and we need more coffins quickly."
Hundreds of thousands remain homeless, squeezed into temporary shelters without heat, warm food or medicine and no idea what to call home after the colossal wave swallowed up communities along the coast.
Associated Press writers Tomoko A. Hosaka and Yuri Kageyama in Tokyo, Tim Sullivan in Higashimatsushima, Lindsey Tanner in Chicago and Veronika Oleksyn in Vienna contributed to this report.