3 Thyroid Cancer Cases Diagnosed in Kitaibaraki City, Ibaraki Prefecture -- Immediately South of Fukushima Prefecture
Kitaibaraki City, Ibaraki Prefecture, is located in the northeastern part of the prefecture, immediately south of Iwaki City, Fukushima Prefecture, and about 70 km south and slightly west of the Fukushima Daiichi nuclear power plant.
On August 25, 2015, Kitaibaraki City released the results of the thyroid ultrasound examination. Below is the English translation of the results and the related newspaper article.
August 25, 2015
Division of Cooperative Community Development
Office of Health Support
【Regarding the Results of Thyroid Ultrasound Examination Project in Kitaibaraki City】
Kitaibaraki City implemented “Thyroid Ultrasound Examination Project: during the two-year period in Fiscal Year (FY) 2013-2014. (Project expenses: 37,173,000 yen)
Subjects were cityい residents age 0 to 18 at the time of the Fukushima Daiichi nuclear power plant accident. The examination was conducted in those age 0 to 4 in FY 2013 and other ages in FY 2014.
Regarding the examination results, the Kitaibaraki City Thyroid Ultrasound Examination Project Evaluation Council, consisting of experts and physicians, reported as follows:
- As screening examination, some would require a detailed examination or be diagnosed with cancer at a fix rate just as expected in a routine health check-up.
- The detailed examination result from FY 2014 revealed 3 cases of thyroid cancer.
- Radiation is unlikely to be the cause of these thyroid cancer cases.
※All participants or their guardians received explanations regarding radiation effects, purpose and method of the examination, and diagnostic category at orientation sessions ahead of time.
Those who were assessed to require a detailed examination (B & C diagnostic category) received explanation about the detailed examination during individual home visits.
Second-round screening is planned. The time of screening will be considered based on the opinions of physicians and experts.
Note: Diagnostic criteria employed by Kitaibaraki City are the same as in Fukushima Prefecture according to Oshidori Mako's inquiry with Kitaibaraki City Hall.
- A1: no nodules or cysts found
- A2: nodules ≦ 5.0 mm or cysts ≦ 20.0 mm
- B: nodules ≧ 5.1 mm or cysts ≧ 20.1 mm
- C: requiring immediate secondary examination
The Asahi Shimbun article dated August 26, 2015
Ibaraki Prefecture: Three Thyroid Cancer Cases in Kitaibaraki City from Last Fiscal Year Examination of Those Age 18 or Younger
Kitaibaraki City has been independently investigating the effect of radioactive substances due to the Tokyo Electric Fukushima Daiichi nuclear power plant accident on children. On August 25, Kitaibaraki City released the results of the thyroid ultrasound examination conducted in FY 2014 on children age 18 or younger (note: at the time of the accident; at exposure). There were 3 cases of thyroid cancer, but it was judged unlikely to be due to the nuclear power plant accident.
After the nuclear power plant accident, the central government conducted thyroid examination in Fukushima Prefecture, but not in adjacent Kitaibaraki City. Due to requests from parents, the city conducted the examination independently. 1184 children who were age 4 or younger at the time of the accident underwent the examination in FY 2013, and none were diagnosed with thyroid cancer.
Examination subjects in FY 2014 was a total of 6,151 children 18 or younger (including children age 4 or younger who did not undergo the examination in FY 2013). Of these, 3,953 wanted to be examined. The results showed 1,746 with no findings, 1,773 to be followed with observation, 72 to require detailed examinations, and 2 to require detailed examinations immediately. 3 were diagnosed with thyroid cancer by the Thyroid Ultrasound Examination Project Assessment Council. However, the cancer was determined unlikely to be due to radiation exposure owing to the Fukushima nuclear power plant accident, considering the supposed exposure dose and the length of time since the accident.
According to tweets by a freelance journalist Ryuichi Kino who contacted the Office of Health Support, Division of Cooperative Community Development, Department of Citizen Welfare at Kitaibaraki City Hall, 3 cancer cases were diagnosed from 74 (72 in category B and 2 in category C) who had detailed examinations, but apparently 2 cases who were in diagnostic category C were not automatically diagnosed with cancer. (It is unclear if this means the 2 "C" cases were eventually diagnosed with cancer after the detailed examination, or they were not diagnosed with cancer). All 3 have been operated on and apparently doing well. The city has no intention of releasing ages and sexes of the three patients, as such information might identify the individuals. Names of the Kitaibaraki City Thyroid Ultrasound Examination Project Evaluation Council members will not be released at the request of some of the members. The Council consists of 6 members — 1 thyroid specialist, 3 physicians including surgeon(s) and general practictioner(s), and 2 city officials. According to the Ibaraki Shimbun article, president of Kitaibaraki City Hospital, Dr. Yoshifumi Uekusa, stated, “Symptoms began to appear 5 years after the Chernobyl accident, and the exposure dose is less in Japan, so it is unlikely to be due to radiation effects.” Apparently, Dr. Uekusa is a member of the Council.
Oshidori Mako contacted Kitaibaraki City Hall and reported that the Thyroid Ultrasound Examination Project Assessment Council (which concluded, "Radiation is unlikely to be the cause of these thyroid cancer cases") included no experts in radiation protection or dose estimation. Oshidori Mako also noted that the radioactive plume blew in the south towards Iwaki City but the lack of precipitation prevented radionuclides from depositing on the ground as it did in Iitate Village. (This means the overall radioactivity of soil may not be high, but residents still might have been exposed to the radioactive plume when it passed through the area). The early exposure dose assessment, based on the soil deposition, has been inadequate for a place such as Iwaki City.
As a matter of fact, paragraph C43 of UNSCEAR 2013 discusses the so-called "south trace" having much higher ratios of Te-129m and I-131 to Cs-137. This suggests a significant amount of radioactive iodine isotopes might have fallen in the "south trace" which includes Iwaki City. As Kitaibaraki City is immediately south of Iwaki City, and the air movement does not stop at the border between the two cities, it is possible for Kitaibaraki City to have received a similar amount of the radioactive plume as Iwaki City.