TOKYO – Radioactive iodine in drinking water was at one point above government safety limits in the prefecture that hosts a radiation-spewing nuclear plant, the Health Ministry said late Saturday after reporting that trace amounts had also been detected in Tokyo and five other prefectures.
The Health Ministry said in a statement that iodine levels slightly above the limit were detected Thursday in Fukushima prefecture, the site of the Fukushima Dai-Ichi nuclear power plant where workers are scrambling to prevent radiation leaks. On Friday, levels were about half that benchmark, and by Saturday they had fallen further.
Drinking one liter of water with the iodine at Thursday’s levels is the equivalent of receiving one-eighty-eighth of the radiation from a chest X-ray, said Kazuma Yokota, a spokesman for the prefecture’s disaster response headquarters.
Earlier, the ministry said tiny amounts of the iodine were found Friday in tap water in Tokyo and five other prefectures. The ministry says the amounts did not exceed government safety limits. But tests on water, which for decades were only done once a year, usually show no iodine.
Outside Fukushima, the highest reading was less than a third of the allowable limit. A ministry official, who could not be quoted by name as is customary, said the government deems the small amounts safe and was awaiting further analysis.
Nuclear reactors at the Fukushima plant began leaking radiation in the days after the March 11 tsunami knocked out its cooling systems. The crisis has raised public alarm about the threat to public heath, and earlier Saturday, the government acknowledged that tests found iodine in spinach and iodine and the radioactive element cesium in milk from some farms 20 to 75 miles (30 to 120 kilometers) from Fukushima.