Fukushima survey lists 12 confirmed, 15 suspected thyroid cancer cases

An ongoing study on the impact of radiation on Fukushima residents from the crippled atomic power plant has found 12 minors with confirmed thyroid cancer diagnoses, up from three in a report in February, with 15 others suspected cases, up from seven, researchers announced Wednesday.


The figures were taken from about 174,000 people aged 18 or younger whose initial thyroid screening results have been confirmed.


                                           2011              2012
Total number of screening
test result  (ages uunder 18)  40000      134000    
Secoundary test required  205   935
  Confirmed                   7     5
  Suspected                           4     11

(table made by WNSCR team) 

Researchers at Fukushima Medical University, which has been taking the leading role in the study, have said they do not believe the most recent cases are related to the nuclear crisis.

They point out that thyroid cancer cases were not found among children hit by the 1986 Chernobyl nuclear accident until four to five years later.


The prefecture’s thyroid screenings target 360,000 people who were aged 18 or younger when the March 2011 meltdown crisis at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear plant was triggered by a major quake and tsunami.


The initial-phase checks the size of lumps and other possible thyroid cancer symptoms and categorize possible cases into four groups depending on the degree of seriousness. Those in the two most serious groups are picked for secondary exams.


In fiscal 2011, after confirming test results from about 40,000 minors, the prefecture sent 205 for secondary testing. Of the 205, seven were diagnosed with thyroid cancer, four came out with suspected cases, and another had surgery but the tumor was found to be benign.

In fiscal 2012, of about 134,000 minors with confirmed initial screening results, the prefecture sent 935 to secondary testing. Among them, five were confirmed with thyroid cancer, while there were 11 suspected cases.


In the Chernobyl catastrophe, thyroid cancer was reported in more than 6,000 children. The U.N. Scientific Committee attributed many of the cases to consumption of milk contaminated with radioactive iodine immediately after the crisis started.


Last month, U.N. scientists assessing the health impact of the Fukushima nuclear crisis said the radiation dose for residents in the region was much lower than Chernobyl and that they do not expect to see any increase in cancer in the future.


Among those aged 10 to 14 in Japan, thyroid cancer strikes about 1 to 2 in a million.

“Fukushima’s survey examines people who have no symptoms across the board and it is hard to evaluate it because there are no comparable data,” a health department official at the Environment Ministry said. “We need to take a careful look at it.”


The official downplayed the possible effects of the nuclear crisis, saying it is likely that Fukushima authorities were able to detect cancer cases early.


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Comments: 2
  • #1

    Steve Athearn (Monday, 10 June 2013 01:13)

    This news is very worrisome. Sorry to dwell on the numbers when real lives are at stake. But let's say the population age 0-18 is 3.6 times the 10-14 age population. Absent more specific data, if we assume "normal" juvenile thyroid cancer cases (in a country which has 50+ atomic reactors) for the entire cohort is the same as the 1 to 2 cases per million given for children 10-14, then that gives 3.6 to 7.2 cases expected per million "normally" in the 0-18 age group.

    Roughly 200,000 children have been screened for the disease, of whom at least 12 and more probably about 24 already have thyroid cancer. (Reports earlier in the year had 3 confirmed and seven suspected cases. From the information above (for fiscal 2011), it would appear that about 4 of the "suspected" have since moved into the "confirmed" category, one turned out benign, while 4 remain "suspected".) Extrapolating these results to a population of 1 million (5 x 200,000), that would give 5 x 12 to 5 x 24 cases - or 60 to 120 cases per million, compared to the expected rate of 3.6 to 7.2 per million. The researchers may be right to suggest a certain caution in interpreting these early results, but categorical statements to the effect that they "do not believe that the most recent cases are related to the nuclear crisis" (if correctly attributed to them) would go beyond legitimate scientific caution when from the huge discrepancy from expected rates a connection with the nuclear crisis must be suspected.

  • #2

    Steve Athearn (Monday, 10 June 2013 16:42)

    I should have annualized the above figures, which cover two years. When that is done (dividing 60 and 120 by two) we arrive at 30 to 60 thyroid cancer cases per million children aged 0-18 per year, or on the order of 10 times the expected number of cases.