Incidents of thyroid cancer and nodules in children have risen significantly among those living in areas contaminated by Fukushima fallout, although the official response is the cancers are unconnected to Fukushima children’s unprotected exposure to Iodine-131:
Fukushima finds 16 new cases of thyroid cancer in young people,” The Asahi Shimbun (May 19, 2015) http://ajw.asahi.com/article/0311disaster/fukushima/AJ201505190041
Here is a compelling article describing efforts in Japan to wind down the Fukushima health survey (Hat Tip: Thank you Tony!):
Follow Up on Thyroid Cancer! Patient Group Voices Opposition to Scaling Down the Fukushima Prefectural Health Survey¹
Aihara Hiroko (Translation by Yuki Miyamoto). Introduction by Eiichiro Ochiai. Asia Pacific Journal (2017) http://apjjf.org/2017/02/Aihara.html
It turned out that a large number of children have contracted thyroid cancers over the last five years: 172 out of ca. 380,000 children by the end of 2015. The majority of them have undergone surgery, and many have been found to have metastasized. This number , and the annual rate per 1,000,000, ca 90, is unusually high, compared with the rate 1 to 3 per 1,000,000 under normal circumstances.
The Fukushima prefectural government and the organization charged with conducting the examination are trying to rationalize the results in many ways, without invoking the radiation impact of the reactor meltdowns. If this is indeed unrelated to the radiation from the damaged Fukushima Nuclear Power Plants, a similarly high rate of thyroid cancer should be found all over Japan. The survey should be expanded in order to see whether that is indeed the case.
In fact, however, as Aihara Hiroko details, the authorities are interested in scaling down the survey in Fukushima itself. They argue, curiously, that the results are causing anxiety and therefore are an example of “reputational damage,” an interpretation that excludes the possibility of actual harm to health and agricultural produce and other commercial activity.The survey is being scaled down because the results are causing "reputational damage"!
Here is an excerpt from my book, Crisis Communication, Liberal Democracy and Ecological Sustainability ( here ) discussing the rising incidents of thyroid cancer among Fukushima children:
Children are likely at greatest risk for health consequences from exposure because they are biologically more vulnerable to radiation since their cells are dividing faster. The thyroid is particularly susceptible to radiation-induced damage because it bioaccumulates radioactive iodine. People with thyroid conditions have an increased risk of dying because of damage that occurs prior to treatment.[i]
Potassium iodide helps block absorption of radioactive iodine but as mentioned earlier in the chapter, distribution was delayed. Consequently, many children in Japan became internally contaminated with radioiodine, in addition to whatever other radionuclides internalized through inhalation and ingestion.
On July 6, 2011 the Japanese press Kyodo reported that in a March 2011 survey of 1,080 children aged 0 to 15 in Iwaki, Kawamata, and Iitate 45 percent of kids in Fukushima survey had thyroid exposure to radiation.[ii]
A separate study measuring thyroid exposure to Iodine-131 conducted between April 12, 2011 and April 16, 2011 and published in Research Reports found “extensive measurements of the exposure to I-131 revealing I-131 activity in the thyroid of 46 out of the 62 residents and evacuees measured”[iii]
In August of 2011, NHK reported that Japan’s nuclear commission had erased children’s exposure data derived from a test of 1,000 children aged 15 or younger who had been screened for radiation affecting their thyroid.[iv]
By February of 2014, there were 75 confirmed or suspected thyroid cancer cases among 270,000 Fukushima Prefecture individuals screened, who were 18 or under at the time of the disaster.[v] The screening committee claimed the Fukushima disaster was an unlikely cause.[vi]
However, the observed frequency of thyroid cancer and nodules exceeds established incident rates. For example, the prevalence of thyroid nodules in children typically ranges from 0.2-5.0 percent,[vii] while in Fukushima, 42 percent of 133,000 children were found to have thyroid nodules and cysts two years after the disaster.[viii]
In 2015 two research articles were published arguing that the rate of thyroid cancer among Fukushima children was excessive. The first study noted that the surge of thyroid cancers detected among 370,000 Fukushima residents aged 18 or younger was “unlikely to be explained by a screening surge” given the incident rate was found to be 20 to 50 times the national average at the close of 2014.[ix]
The second study observed that the rate of thyroid cancer being detected in Fukushima’s children exceeded the rate found after Chernobyl.[x]
However, Shoichiro Tsugane, Director of the Research Center for Cancer Prevention and Screening, asserted that “Unless radiation exposure data are checked, any specific relationship between a cancer incidence and radiation cannot be identified,” and noted there exists a “global trend of over-diagnosis of thyroid cancer….”[xi]
[i] Anne Laulund, Mads Nybo, Thomas Brix, Bo Abrahamsen, Henrik Løvendahl Jørgensen, Laszlo Hegedüs, “Duration of Thyroid Dysfunction Correlates with All-Cause Mortality. The OPENTHYRO Register Cohort,” PLOS, 9.10(2014): 1-8, e110437-110 DOI: 10.1371/journal.pone.0110437.
[ii] “45% of kids in Fukushima survey had thyroid exposure to radiation,” The Mainichi (July 5, 2011): http://mdn.mainichi.jp/mdnnews/news/20110705p2g00m0dm079000c.html.
[iii] Shinji Tokonami, Masahiro Hosoda, Suminori Akiba, Atsuyuk Sorimachi, Ikuo Kashiwakura, and Mikhail Balonov “Thyroid doses for evacuees from the Fukushima nuclear accident.” Scientific Reports, 2(507)(2012): 1. doi:10.1038/srep00507.
[iv] “Nuclear Commission erases children's exposure data,” NHK (August 11, 2011). http://www3.nhk.or.jp/daily/english/11_14.html.
[v] Nose, T., & Oiwa, Y. (2014, February 8). Thyroid cancer cases increase among young people in Fukushima. The Asahi Shimbun. Available: http://ajw.asahi.com/article/0311disaster/fukushima/AJ201402080047
[vi] “Eight more Fukushima kids found with thyroid cancer; disaster link denied,” The Japan Times (February 7, 2014): http://www.japantimes.co.jp/news/2014/02/07/national/eight-more-fukushima-kids-found-with-thyroid-cancer-disaster-link-denied/#.U2Zvr61dVXo
[vii] Gerber, M. E., Reilly, B. K., Bhayani, M. K., Faust, R. A., Talavera, F., Sadeghi, N. & Meyers, A. D. “Pediatric thyroid cancer,” Emedicine. (2013): http://emedicine.medscape.com.ezproxy1.lib.asu.edu/article/853737-overview.
[viii] Haworth, A. (2013, February 23). After Fukushima: Families on edge of meltdown. The Guardian. Available http://www.theguardian.com/environment/2013/feb/24/divorce-after-fukushima-nuclear-disaster.
[ix] Toshihide Tsuda, Akiko Tokinobu, Eiji Yamamoto and Etsuji Suzuki, “Thyroid Cancer Detection by Ultrasound Among Residents Ages 18 Years and Younger in Fukushima Japan: 2011 to 2014,” Epidemiology (2015), 1-7.
[x] Shigenobu Nagataki and Takamura, Noboru, “A review of the Fukushima nuclear reactor accident: radiation effects on the thyroid and strategies for prevention. Current Opinion in Endocrinology, Diabetes & Obesity, 21.5 (October 2014): 384–393. doi: 10.1097/MED.0000000000000098, available http://journals.lww.com/co-endocrinology/pages/articleviewer.aspx?year=2014&issue=10000&article=00012&type=abstract.
[xi] “New Report Links Thyroid Cancer Rise to Fukushima Nuclear Crisis,” The Japan Times, Oct 7, 2015, accessed October 8, 2015, available http://www.japantimes.co.jp/news/2015/10/07/national/science-health/new-report-links-thyroid-cancer-rise-fukushima-nuclear-crisis/#.VhU3aCtBmFt