East Japan Earthquake    March 11, 2011

Babies can bathe, be shampooed / Iodine levels in water not dangerous for infants; now within safety limits

March 25, 2011

In light of a recent warning that radioactive iodine exceeding the safety limit for infants was detected in Tokyo's tap water, experts said the level was not harmful for babies for the time being, and that babies could be bathed or have their hair washed in it. The amount of radioactive iodine in Tokyo's drinking water Thursday fell back below the recommended safety levels, according to city government officials. Tokyo metropolitan government officials said 210 becquerels of radioactive iodine were detected per kilogram of water at the Kanamachi water purification plant in Katsushika Ward, Tokyo, on Tuesday. Iodine is likely to stay in the thyroid gland and may cause thyroid cancer. The hazardous iodine level provisionally defined under the Food Sanitation Law for drinking water is 300 becquerels per kilogram in general, and 100 becquerels for infants as they are more susceptible to the chemical. "The hazardous level [defined by the law] is much stricter than the [unspecified] value that would have adverse health effects," said Atsushi Kasai, former laboratory chief of the now-defunct Japan Atomic Energy Research Institute, which later merged with another institution to become the Japan Atomic Energy Agency. Kasai said the level of iodine detected in Tokyo's tap water on Tuesday is not hazardous even if infants drink it for a short period, although it is best for infants not to drink such water at all. He also said the iodine would not be absorbed through bathing or washing hair with such water. Other experts said tap water should be drunk if bottled water is unavailable. "Not drinking enough water will trigger dehydration in infants," an expert said. "It's fine for babies to drink tap water if other drinking water is unavailable," the Health, Labor and Welfare Ministry said, before adding that the level recorded Tuesday is not harmful for older people, and is considered safe for pregnant and breast-feeding women. "It's safe to drink tap water as per usual if the radioactive iodine levels stay within the limit set for ordinary people," a health ministry official told reporters. Meanwhile, if mineral water is used to dissolve powdered milk, mothers should be aware of the water's "hardness" level because hard water, or water with a high concentration of minerals such as calcium, can affect infants' kidneys. Imported water tends to contain a higher concentration of minerals, and mothers are recommended to check food labels and descriptions. A spokesperson of baby products retailer Bean Stalk Snow Co. says the company recommends consumers use water with a hardness of 300 milligrams per liter or less. (The Yomiuri Shimbun)

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Iodine spreads to Tokyo Iodine was detected in tap water about 200 kilometers away from the No. 1 nuclear plant in Fukushima Prefecture. According to Toshimasa Ohara, head of the National Institute for Environmental Studies' regional atmospheric modeling section, radioactive iodine-131 from the troubled plant is likely to have carried downwind and along with the rain to the water purification plant in Tokyo and around its Edogawa river intake channel. When radioactive iodine levels breach infant safety levels, the Tokyo metropolitan government instructs the public as follows:
-- Mothers should not let infants drink tap water, nor use it to dissolve powdered milk.
-- Water showing elevated iodine levels is considered a health risk if it is consumed long term. So, it is fine to drink tap water if alternative drinking water is temporarily unavailable.
-- It is all right to use tap water for daily tasks such as washing babies' hands, gargling and giving baths. No danger is posed if infants accidentally swallow water while gargling.


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