Tsubokura et al have published a paper regarding the title above in the recent issue of JAMA. I have not read that published paper yet but have already read the same content in japanese. It concludes, overall, the radiation dose in the population examined by a whole body counter have been decreasing and remain low. This is seemingly somewhat a relieving finding to us.
However, there could be a few issues in this study. First, as the author points out, the people under study voluntarily applied for the study. They could not represent the general population. Since the examinees could be radiation issue conscious, they could be careful for external as well as internal radiation exposure in their lives. There could be a bias toward low value. The study should be performed for the group statistically identical to the general population.
Secondly, IRPA published a data that the children in Chernobyl had high rate in chromosomal abnormality even though they were normal as for the radiation dose measured by a whole body counter in comparison with the normal control in Finland.
This data might mean one hit by radiation could cause sequelle for the genetic as well as chromosomal abnormality which are related with carcinogenesis in the future.
There have been a few reports on the relationship of Cessium accumulation in urinary tract epithelium and possible carcinogenesis there. Here is an example;
Carcinogenesis. 2009 Nov;30(11):1821-31. Epub 2009 Jul 30
The whole body counter could not measure the content of radioactive substance in each organ. If Cessium could specifically accumulate in urinary tract epithlium, the whole body counter is not appropriate for its measurement. How do they answer about this limitation of the whole body counter? This is the 3rd question.
Since the data in Chernobyl is not complete as for these issues, we are getting into the world nobody has experienced in the past. We should not conclude the radiation issue is so serious or it is an easyproblem until we could reach any scientific conclusion. Careful and scientific observation is mandatory.