Search for Strontium-90 in Deciduous Teeth*
by Dr Alex Rosen ( Pediatrician/Vice President, IPPNW Germany )As a result of the Fukushima nuclear catastrophe huge amounts of radioactivity werereleased into the environment.

While the Japanese authorities made much of thecontamination by radioactive iodine and cesium and while these radioisotopes aremeasured regularly in samples of soil, water and foodstuffs,

the radioactive strontium

contamination of humans and the environment is hushed up.
Contamination maps do not exist ; at best, strontium measurements are carried out sporadically by
individual research groups. Furthermore, strontium is not at all looked for in the foodstuffsdatabase, which is used to calculate the radiation exposure of the population through taking incontaminated food. But it is known that relevant amounts of radioactive strontium were found in
the teeth and bones of livestock in Fukushima. *1)
Therefore, independent scientists in Japan have set themselves the objective of investigating theradioactive strontium exposure of the population. The aim is to draw attention to the hitherto
ignored risks of leukemia and forms of bone cancer posed to the inhabitants in the contaminatedareas. This is particularly relevant in the case of children who are at a significantly higher risk of
becoming diseased than adults.
In future years deciduous teeth are expected to be collected throughout Japan in order to measure
the levels of strontium within them. It is important that not only the children from the especiallycontaminated areas, but also that people from all age groups from across Japan donate theirdeciduous teeth, so that the analyses can discern chronological and regional differences. The survey
data

could then be used as biomarkers to assess the total strontium exposure of individualpopulations and age groups.
Furthermore, along with donating deciduous teeth, donors will provide information on theirnutrition and drinking water during infancy ( breast milk or powdered milk, bottled mineral water or
tap/well-water), as well as their place of birth and residential history. It is known from past studies
that nutrition composition during the first year of infancy can have a significant impact on thestrontium contamination of the body. This factor is also to be investigated in Japan so that, if
necessary, relevant recommendations for infants can be made.
As the detection of strontium in teeth is technically complex and very work-intensive, the initiators of
the study sought international expertise from the Basel Cantonal Laboratory, Switzerland, which iswell versed in the methodology of strontium detection. At present 200 deciduous teeth from Japanare being examined in Basel. As it is intended for the surveys to be conducted in Japan, the1

establishment of a suitable laboratory

there and the training of staff are pre-requisite to thisendeavour. The research team is confident that in the end, however, the research results will justify
the effort, and plans are for the surveys to be performed over several decades in order to document
the temporal change of the strontium exposure of the population. Strontium has a physical half-lifeof 28.8 years.
The aim of the study is to determine the true extent of the strontium contamination and to give
recommendations to the affected municipalities and prefectures in order to protect the health of theaffected children. The IPPNW Germany endorses this Japanese deciduous teeth study and has joined
the ' Preserving Deciduous Teeth Network ', a promoters' network, to aid the start-up of the study
programme. *2)

First results are expected to become available in a few years, but the scientists

are asking for patience. At the age of six to 12 years most of the baby teeth fall out, so thatstrontium exposure can be measured only with multi-year latency.
The fact that this important investigation is not conducted by official bodies, but by independentscientists, says a lot about the political environment in Japan, where state institutions at all levels areunder extraordinary influence of the nuclear industry and are pressured by superior authority toshelve the Fukushima dossier as soon as possible. The work of the scientists of the PDTN is highly
valuable in that good science is used to put pressure on the authorities not to abandon the people
in the contaminated areas to their fate.

(English Translation: Rie Groeger)✫✫✫✫✫✫✫✫✫✫✫✫✫✫✫✫✫✫✫References*The original article is entitled 'Suche nach Strontium-90 in Milchzähnen' and appears here on theIPPNW Germany homepage*1) Sr-90 and Cs-137 Concentrations in Cattle's Teeth and Bones in the Evacuation Zone of FNPP
http://pdn311.town-web.net/english/sample/img/graph/ushi_big.pdf*2) Preserving Deciduous Teeth Network (PDTN) Homepage: http://pdn311.town-web.net/english/

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