Re: I-131 Thyroid Uptake

[Andy Hull <hull@mail.sep.bnl.gov>]

Mike,
Having become aware of the higher than expected incidence of thyroid cancer
in those who were very young and in the deposition area at the time
Chernobyl accident, I found some interesting information in the published
proceedings of a July 1988 Joint WHO/CEC Workshop on  Iodine Prophylaxis
Following Nuclear Accidents, E Rubrey and E Smales Eds, Pergamon Press
1990. In a presentation on Problems in Dosimetry, Including Consideration
of Special Groups: In Utero, The Neonate, Children and Adults, J.F. Malone
and P. Gilligen state  "after birth there is a dramatic rise in thyroid
activity, reflected in a very large rise in the order of 80%... As a result
of this it has been estimated that the newborn is highly susceptible to
large  absorbed doses from radioiodine." In their  Table 5, from Fisher et
al 1962, they indicate  that for a Term infant of 3kg, at Age 0-2 days a
78% mean uptake and Age 2-55days 20%.  They go on to state "This dramatic
rise is relatively short lived and returns to a value typical for
adults within a week or two.
 
If you need more details, let me know.
  
   
At 12:09 PM 1/27/99 -0600, Michael McCarty wrote:
>Does anyone have references to suggest for answers to the following
questions:
>
>What is the typical percent of a iodine intake (we happen to be concerned
with I-131) that will be taken into the thyroid gland?  My 1972 copy of
Shapiro, "Radiation Protection" says 30%, but there is some indication that
it may be as low as 3% (at least for some individuals) according to other
sources.
>
>So, is the answer a range, say about 3 to 30%?  Does the pathway make a
difference, e.g. nuclear medicine injection vs. reactor release and
subsequent accidental inhalation?
>
>Thanks,
>Mike McCarty
>Health Physicist/Emergency Planner
>mccartmj@state.mi.us
>
>Michigan Department of Environmental Quality
>Drinking Water and Radiological Protection Division
>Radiological Protection Section
>Nuclear Facilities Unit
>   phone:  517-335-9414
>     fax:  517-335-8706
>
>mailing address:
>     Michigan Department of Environmental Quality
>     Drinking Water and Radiological Protection Division
>     3423 North Martin Luther King Jr. Blvd
>     P.O. Box 30630
>     Lansing, MI 48909-8130
>
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