[ RadSafe ] Fukushima children thyroid cysts?

[Andrew McEwan]

Some notes of reports on thyroid cysts and nodules.

The Fukushima Health Management Survey has carried out a screening programme
on residents aged 18 years and younger using ultrasound scanning to detect
prevalence of nodules and cysts in thyroids. In 38114 participants examined
in the period April 2011 to March 2012 35.8 percent had nodules or cysts
detectable, 186 (0.5%) being greater than 5 mm for nodules or 20 mm for
cysts. Of  94975 individuals screened between April 2012 and January 2013
44.2 % had cysts or nodules. These findings are unlikely to have any direct
relationship to thyroid doses received by the study population. In the early
1960s the U.S. Public Health Service conducted studies on the prevalence of
nodules in the thyroids of children in Arizona, California, Nevada and Utah.
They observed a large percentage of children with nodules.  A part of the
study was conducted to determine if nuclear testing at the Nevada Test Site
was the cause of these nodules.  The USPHS also examined regions of the US
where fallout from testing were low and found that the nodules observed in
children’s thyroids were not statistically different between the four States
mentioned above and other regions that were studied.

Takahasi et al [International Journal of Epidemiology 1999; 28, 742-749]
undertook a thyroid screening programme in the Marshall Islands using
palpation, high resolution ultrasound and fine needle biopsies of palpable
nodules. In addition, various parameters of thyroid function (free T3, free
T4, thyroid stimulating hormone [TSH]) and anti-thyroid antibodies were
examined in large proportions of the total population examined. Since
dietary iodine deficiency is an established risk factor for thyroid nodules,
iodine concentration in urine samples of 362 adults and 119 children was
measured as well as the iodine content of selected staple food products.
The expected high prevalence of thyroid nodules, found in an earlier study
[Takahashi et al Health Phys. 73(l): 199-213; 1997] was confirmed. In this
earlier study 1,322 Marshallese born before 1965 were given a thyroid
examination using neck palpation, fine needle aspiration biopsy, and high
resolution ultrasound imaging. Of that group, 815 were alive at the time of
the BRAVO test on 1 March 1954 and some were exposed to fallout. Two hundred
sixty-six people with thyroid nodules were found (32.6% ): 132 were palpable
nodules (16.2%), and 134 were nodules that could be diagnosed with
ultrasound only (15.7%).
In the later study there was no indication of an increased rate of impaired
thyroid function. A moderate degree of iodine deficiency was found which the
authors considered might be responsible for some of the increased prevalence
of thyroid nodules in the Marshallese population. There was no indication
that the high prevalence of nodules was related to weapons testing exposure.

Guth S, Theune U, Aberle J, Galach A, Bamberger CM. [Eur J Clin Invest. 2009
Aug;39(8):699-706. doi: 10.1111/j.1365-2362.2009.02162.x.] found the
prevalence of nodules in the German population depended on the type of
ultrasound scanner employed. The prevalence of thyroid nodules in a healthy
population is high: in the German Papillon study, nationwide ultrasound
screening of more than 90 000 people using 7.5 MHz scanners revealed the
presence of thyroid nodules in 33% of the normal population. A study
employing more sensitive 13 MHz scanners was carried out. Six hundred and
thirty-five consecutive patients (33% female, 67% male, mean 56.7 years)
presenting for a preventive health check up underwent ultrasound screening
of the thyroid gland (Siemens Acuson Antares, 13 MHz-linear scanner, B-mode
and Power mode) and measurement of the basal TSH (thyroid stimulating
hormone) value. Size and degree of vascularization of the thyroid gland and
of nodules were determined and analysed retrospectively. In 432 of 635
patients, thyroid nodules could be detected with an increasing incidence
with age, in 338 without goiter. Mean thyroid size was 12.3 mL for women and
20.5 mL for men correlating strongly with body weight. Fifty-three
percentage of the nodules were smaller than 5 mm. Incidence of thyroid
dysfunction was only 4%. No cancerous lesions could be found.
Using the 13 MHz technology, a substantially higher prevalence of thyroid
nodules (68%) than the Papillon study (33%) was found. The authors noted
that even if the studied population was older than in Papillon, the
difference remains in comparable age groups. This is due to the higher
sensitivity of 13 MHz scanning.

Andrew McEwan



-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu]On Behalf Of Eric Goldin
Sent: Wednesday, 27 November 2013 4:58 a.m.
To: radsafe at health.phys.iit.edu
Subject: [ RadSafe ] Fukushima children thyroid cysts?


Hey folks,  looking for some actual information here, not opinions.  Last
night I was told by someone that he's heard a report about children from the
Fukushima area showing up with thyroid cysts, presumably caused by
radioiodine from the plant.  Way too early for thyroid cancer (latency) but
I'm not familiar with "radiation-induced cysts."  The information reportedly
is supported by doctors in the area and parents are concerned.  Does anyone
out there know something factual about this issue?  I'd like to find out if
it's simply a result of additional screening rather than a real health
problem caused by radiation.  


Thanks,  Eric Goldin, CHP
emgoldin at yahoo.com
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