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Unexplained Discrepancies in Fukushima Thyroid Cancer Age-Gender Distribution Graphs

The Twelfth Fukushima Prefectural Oversight Committee convened on August 20, 2013, reporting the latest findings of the health survey.  The thyroid examination result showed an increase in the number of children confirmed or suspected of thyroid cancer from 28 to 44, as reported in the previous post:

The information was almost instantly available to the Twitter and social network communities, thanks to the independent journalists attending the committee meeting.  Some members of the public, as well as the journalists attending the meeting noticed a strange discrepancy looking at the age and gender distribution graph of the 44 cases confirmed or suspected of cancer, as shown below.

The June 5, 2013 report showed the graph below for the 28 cases.
(This can be seen on page 32 of the comprehensive report here: It can also be seen on page 11 of the official English translation of the June report here:

In comparing the two graphs, the following observations are made:
1. Both graphs show age as of March 11, 2011, so the basic age distribution should not differ between the two graphs.
2. In age 11, the June graph shows 3 males, yet the August graph shows none.
3. In age 15, the June graph shows 4 females, yet the August graph shows only 2.
4. In age 17, the June graph shows 4 females, yet the August graph shows only 3.
5. In age 18, the June graph shows 2 males, yet the August graph shows only females, totally flipping the gender.

According to the astute observation of a freelance journalist, Mako Oshidori, the Committee released the revised June graph on August 20, 2013, as shown below.
(This can be seen on page 11 of the thyroid examination result file here:

Comparing the original and revised June graphs, it appears as if the age of the patients, in addition to gender, was categorized totally wrong.

According to Mako Oshidori, who was present at the committee meeting on August 20, 2013, an announcement was made in the beginning of the meeting, in regards to the change that had been made in average age and standard deviation on page 5 of the thyroid examination report.  Apparently, some discrepancies were pointed out by one of the committee members who reviewed the material prior to the meeting.  The announcement was intended to notify the committee members that the material distributed at the meeting contained the corrected version.

Investigation by Mako Oshidori revealed that an official at the Health and Welfare Department of Fukushima Prefecture government, in charge of the Prefectural Health Management Survey, stated that "the original data was handled incorrectly due to the counting error by Fukushima Medical University."

For information, the corrected information that was distributed at the meeting is shown below:

① Results of cytological examination


Apparently, after making the correction, The committee wondered if the previous report in June needed corrections, and it did indeed need corrected.

Here's the June 5, 2013 results prior to the correction:

The revised June 5, 2013 results, published online on August 20, 2013 is shown below, with the correction inserted by the author in red for clarification in this post:

Going back to the discrepancies in the age and gender distribution graphs, the original graph was online for over two months without anybody noticing the discrepancies until the new August data was released.  The gender ratio in thyroid cancer cases is drawing a lot of attention, as can be seen in the July 20, 2013 post of the English translation of the June 9, 2013 article by Mako Oshidori:  

In children who developed thyroid cancer after the Chernobyl nuclear accident, the ratio of females with thyroid cancer was higher than males.  In general population, adult thyroid cancers are found in more females than males.  The June results showed an even male to female ratio at 14:14 overall, but the FY 2012 result had a male to female ratio of 9 : 7, with slight dominance of males, which appears to be an anomaly.  Now the number of cases confirmed or suspected of thyroid cancer has increased from 28 to 44, and the male to female ratio is 18 : 26.  This change in gender ratio might be explained by more cases being discovered and the gender ratio approaching a natural ratio expected of thyroid cancer.  However, the fact that "the original data was handled incorrectly due to the counting error by Fukushima Medical University." raises questions about the integrity of the thyroid examination process itself, especially considering the continued denial by Fukushima Medical University of a possibility that any of these cancer cases could be related to radiation exposure due to the Fukushima nuclear accident.  The committee has repeatedly refused to reveal the exposure dose information for the cancer cases, citing confidentiality.


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Fukushima Thyroid Examination Fact Sheet: September 2017 (Long Version)

Fukushima Thyroid Examination Fact Sheet:  September 2017
✴Copying or re-posting part or whole of this post is not permitted. Please link to this post instead.

Note: Corrections were made in the following paragraphs in pink color on October 17, 2017.
Second paragraph in section "Screening protocol"
First paragraph in section "Thyroid cancer cases"
First paragraph in section "Transparency and integrity of data"
Second paragraph in subsection "1. A limited time interval after the accident" in section "Official stance on radiation effects"
Fourth paragraph in subsection "2. Very low doses" in section "Official stance on radiation effects"

Note: A shorter version of this fact sheet has been e-published on the website of Kagaku by the Iwanami Publishers. It can be downloaded from this link. Citation in AMA style is as follows: Hiranuma Y. Fukushima thyroid examination fact sheet: September 2017. Kagaku. 2017;87(9):e0001-e0011.


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