Radiation in Tokyo tap water at safe level

(CNN) — New tests Thursday showed that radioactive iodine in Tokyo’s tap water has dropped to levels considered safe for babies — just hours after authorities announced plans to distribute bottled water to tens of thousands of parents around the Japanese metropolis.

Tests from 6 a.m. at the Kanamichi Water Purification Plant, which provides water to 23 wards in Tokyo as well as five other cities, showed 79 becquerels of radioactive iodine per kilogram of water, the city government said in a news release.

A becquerel is a measurement of radioactive intensity by weight.

This is below the 100 becquerel level, the maximum that could be considered safe for infants ages 1 and younger. And it is well below the 210 becquerel reading measured Tuesday night.

As a result, Tokyo Gov. Shintaro Ishihara told reporters on Thursday that he was lifting the recommendation that babies not drink tap water — though bottled water will continue to be distributed to households with youngsters.

Shintaro said that 240,000 such 550-millileter bottles will be given out Thursday, with a like number set to be distributed on Friday.

Despite the positive development, concerns remain over how radiation from the Fukushima Daiichi nuclear power plant may affect food, water and air in the Asian nation.

The power facility and its six reactors were seriously damaged by a March 11 earthquake and subsequent tsunami.

Most of the 9,523 confirmed dead perished soon after the quake and walls of water struck northeast Japan. At least 16,067 remain missing and 2,755 were injured, the National Police Agency said.

Test results released at 1 p.m. Thursday showed two plants in the Chiba prefecture still have radioactive iodine levels above the legal limit for infants.

The Chiba Nogiko water treatment plant had a measure of 220 becquerels of radioactive iodine per kilogram of water, while the Kuriyama facility had a reading of 180 becquerels, according to a statement from Chiba’s waterworks bureau. These two plants both provide water for the city of Matsudo, about 20 miles northeast of Tokyo.

As to Tokyo itself, Chief Cabinet Secretary Yukio Edano had said earlier Thursday that households in that city with children under age 1 will receive bottled water from the government.

Authorities have advised day care centers and other such facilities not to use tap water for drinks or to prepare baby food. More bottled water is expected to be distributed in the future, according to NHK.

Companies that package bottled water are being encouraged to increase their production, Edano said.

But he stressed that the levels found in Tokyo’s tap water thus far are not considered dangerous for adults.

“Except for infants, the radiation levels will have no effect on people,” the secretary said.

The level set for infants is “very conservative,” said Dr. James Cox, radiation oncologist at MD Anderson Cancer Center in Houston and a CNN consultant. But elevated radiation levels are considered a problem for small children, as their thyroid glands are more susceptible to radiation.

“Erring on the side of caution for the extreme degree for children makes good sense,” Cox said. For adults, “as far as the immediate health risk, something that would make people sick, I don’t think that would come close to it.”

The assessments appeared to have little effect on Tokyo residents, who snapped up bottled water in droves.

Grocery store owner Seiji Sasaki said he had 40 cases of water in his store, but they were gone quickly.

Japanese officials also expanded food shipment restrictions Wednesday after the health ministry said tests detected radioactive materials at levels exceeding legal limits in 11 types of vegetables grown near the Fukushima plant.

Prime Minister Naoto Kan asked Ibaraki Prefecture to suspend shipments of raw milk and parsley, Edano said.

The government of Fukushima Prefecture also told residents not to eat leafy vegetables, he said.

Radiation levels in the food would not cause health problems right away, Edano said, but if they rise, they may reach levels risky to human health.

The decision to prohibit produce sales is another potentially devastating blow to a part of northeast Japan hit by the earthquake and tsunami.

Fukushima ranks among Japan’s top producer of fruits, vegetables and rice. Ibaraki, south of Fukushima, supplies Tokyo with a significant amount of fruits and vegetables and is the third-largest pork producer in the nation.

“This is our livelihood,” a Fukushima farmer told Japanese television network TV Asahi. “It’s a huge problem that we are unable to ship all our produce. We raised (this produce) with our own hands. It’s unbearable that we would have to throw it all away.”

Hong Kong on Wednesday said it was restricting food and milk imports from certain prefectures over the radiation concerns. The United States had previously announced import alerts covering milk, milk products, fresh vegetables and fruit from prefectures near the reactors.