New radiation tests show "acceptable" results

July 13, 2012

Radiation exposure in Fukushima restudied

http://www3.nhk.or.jp/daily/english/20120713_34.html

Japanese researchers say the maximum radiation exposure of adult residents in Fukushima after the nuclear plant accident there was below the international safety standard.

The researchers at Hirosaki University in northern Japan examined the thyroid glands of 62 Fukushima residents in April last year, soon after the accident. In their initial report released in March, they said the maximum exposure level was 87 millisieverts.

The team reexamined the exposure levels by using detailed data, including that on the spread of nuclear substances called radioactive plumes after the accident.

In their latest report, the researchers said the maximum exposure was 33 millisieverts for adults and 23 millisieverts for those under the age of 20.

The levels were less than half of previously released figures, and lower than an internationally accepted limit of 50 millisieverts.

One of the researchers, Professor Shinji Tokonami, says the latest results are highly reliable because they were based on more accurate data than before.

Tokonami adds that the health conditions of children should be continuously monitored as they are at higher risk of thyroid radiation exposure.