More than 3 millisieverts of radiation has been measured in the urine of 15 Fukushima residents of the village of Iitate and the town of Kawamata, confirming internal radiation exposure, it was learned Sunday.
Both are about 30 to 40 km from the Fukushima No. 1 power plant, which has been releasing radioactive material into the environment since the week of March 11, when the quake and tsunami caused core meltdowns.
"This won't be a problem if they don't eat vegetables or other products that are contaminated," said Nanao Kamada, professor emeritus of radiation biology at Hiroshima University. "But it will be difficult for people to continue living in these areas."
Kamada teamed up with doctors including Osamu Saito of Watari Hospital in the city of Fukushima to conduct two rounds of tests on each resident in early and late May, taking urine samples from 15 people between 4 and 77.
Radioactive cesium was found both times in each resident.
Radioactive iodine was logged as high as 3.2 millisieverts in six people in the first survey, but none was found in the second survey.
The data indicate accumulated external exposure was between 4.9 and 13.5 millisieverts, putting the grand total between 4.9 to 14.2 millisieverts over about two months, they said.
"The figures did not exceed the maximum of 20 millisieverts a year, but we want residents to use these results to make decisions (to move)," said Kamada.