Studying teeth of people exposed to Bikini Atoll test

August 8, 2014

Bikini Atoll nuclear test exposed fisherman to radiation level equivalent to Hiroshima

http://mainichi.jp/english/english/newsselect/news/20140808p2a00m0na008000c.html 

A fisherman around 1,300 kilometers from a United States nuclear bomb test site at the Bikini Atoll in 1954 was affected by a radiation amount about the same as being 1.6 kilometers from the Hiroshima atomic bomb hypocenter, according to research results.

The findings were revealed by professor Shin Toyoda of Okayama University of Science at a meeting of experts on Aug. 7. Toyoda's research group used technology called "electron spin resonance" to measure the number of unpaired electrons in the enamel of two molars and one canine tooth provided by two men on fishing boats exposed to the Bikini Atoll nuclear test.

Toyoda says the researchers took advantage of the fact that unlike in cells, digestion does not occur in tooth enamel, so the effects of radiation exposure remain unaltered. They found evidence of up to 414 millisieverts of radiation exposure from the nuclear test from the enamel of a Kochi Prefecture man in his 80s. The other man was found to have been exposed to up to 252 millisieverts. The researchers accounted for additional radiation exposure over the years from sources like medical x-rays.

The research group was put together at the urging of Hiroshima University's professor emeritus Masaharu Hoshi. It aims to uncover information about the Bikini Atoll nuclear test by researching official documents as well as the teeth and chromosomal abnormalities of people who were on boats exposed to the radiation. The group is continuing to ask for teeth from exposed people for further research.

August 08, 2014(Mainichi Japan)