Re: Potassium Iodide

["J. J. Rozental" <josrozen@netmedia.net.il>]

At 11:45 AM 7/24/98 -0500, you wrote:
>This is in response to J.J. Rozental and Scott Sorensen's recent
>contributions.
>
>I think the fallacy (if any) in the assumptions and calculations is in
>the adverse risk estimates. I for one find it incredible, on the basis
>of discussions with Charlie Wills and others, that "the risk of death
>following iodine prophylaxis is 3(E-9)" or 3 in a billion.  The other
>adverse risk numbers quoted by Mr Rozental are, with all due respect, to
>me equally improbable.
Is there a consensus on these issues? This is of interest to Province of
>Ontario officials, since future planning depends on an acquaintance with
>not only the benefits but also the risks of KI prophylaxis.
>
>Dr A A Pilt
>Emergency Measures Ontario
>
>aadu.pilt@jus.gov.on.ca

Dr. Pilt, 

Considering your statement, let me transcript  the complete text and
reference for the  information that I provided: IAEA Safety Series 109 -
Intervention Criteria in a Nuclear Radiation Emergency, 1994, page 81

I.34 - Values quoted in the literature for the probability of side effects
from the intake of stable iodine differ widely, mainly because of
differences in the dietary intakes of iodine and the prevalence of thyroide
diseases, which is very much higher among infants and young persons. The
administration of stable iodine to eldery people and to people with iodine
deficient diets is therefore potentially more serious. Ref.(1) estimates
that the probability of adverse effects to the population is 10E(-6) to
10E(-7) for a dauly therapeutic dose of 300 mg. This figure includes the
probability of hypothyroidism, hiperthyroidism, thirotoxicosis and goitre,
the principal concerns. The risk of death following iodine prophylaxis can
be estimated to be of 3E(-9). A review of the experience gained in Poland
following the Chernobyl accident Ref. (2) showed an incidence in adults of
4E(-7) of severe health effects and an incidence of 6E(-4) for mild to
moderate effects. No adverses effects reported in the 10E(7) children who
took potassium iodine. On the other hand, Ref. (3) indicates that the
probability of developing hyperthyroidism among eldery goitrus people after
taking 100 mg/d of potassium iodide for 14 days is of the order of 7%. In
view of the probability of endemic goitre in various countries, this side
effect is an important consideration for the use of iodine prophylaxis in
the eldery population.

Ref.
(1) National Council on Radiation Protecdtion and Mesurements, Protection of
the Thyroid Gland in the Event of Releases of Radioiodine, NCRP Rep.,
Washington DC, 1977
(2) Nauman, J., Wolff, J. Iodide Prophylaxis in Poland after the Chernobyl
Reactor Accident: Benefits and Risks, Am. J. Med. (1993/1994) 524-532
(3) Malone J., Unger, J., Delange, F., Lagasse, R., Dumont, J.E., "Thyroid
Consequences of Chernobyl in EEC", Improvement of Practical Countermeasures:
Preventive Medication, Post Chernobyl Action, Rep. EUR-12556, CEC, Brussels,
1991

On the other hand taking into consideration Ref. (4)  

The Experience in Poland following the Chernobyl accident shows that the risks
of serious  side effects from a single dose of stable iodine are very low
(less than 1 in 10E(7) in this age group and less   than   10(E6) in adults.

Ref.(4) Manual on Public Health  Action in Radiation Emergencies - WHO,
European Centre for  Environmental and Health, EUR/ICP/EHAZ 94                

J.J. Rozental
josrozen@netmedia.net.il
Israel