›› Potassium Iodide
Potassium Iodide is a salt
with the chemical formula KI. Chemically, it is not very
different from other iodide salts, and shares the same crystalline
structure common to other halogen salts, such as ordinary table salt
Sodium Chloride, NaCl.
For years, people have been using potassium iodide in
photography. The salt is used in a simple reaction with
silver nitrate to form silver iodide, a vital component for high-speed
photographic film. It has also been in use as an expectorant
to treat coughs and lung congestion.
Potassium iodide is also added to most table salts today, in small
amounts. Because the element iodine is a necessary
requirement for important metabolic enzymes made by the thyroid gland,
humans need some quantity of it in their diet to remain
healthy. In coastal areas where marine foods are eaten
regularly, iodine deficiency is uncommon, however in more remote inland
areas or arid equatorial climates it is much more common and leads to
the serious condition ‘goiter’. Since
potassium iodide looks and even tastes similar to sodium chloride, it
makes a great iodine supplement in table salt. When you
purchase a salt that is advertised as ‘iodized’,
that means it contains potassium iodide.
More recently, potassium iodide has found a more dramatic application
for use in nuclear emergencies. Nuclear fallout raises the
levels of radioactive iodine in the environment to dangerous
amounts. Radioiodine builds up to toxic levels in the thyroid
and can cause serious damage to the gland. Potassium iodide
works by competitively inhibiting radioiodine from building up in the
thyroid.
In recent years, the FDA has approved potassium iodide tablets for use
as a last resort form of protection in a nuclear emergency.
The ideal protection is to evacuate a potentially radioactive area
altogether. Potassium iodide does not protect someone from
the other dangerous effects of radiation poisoning, including DNA
damage, which leads to cancers and other life threatening
illnesses. However, if evacuation is not feasible, potassium
iodide tablets can at least offer protection from thyroid damage, which
is one of the more immediate effects from too much radiation.
Potassium iodide is made in a simple reaction between a potassium base
with hydroiodic acid. It can also be made by treating an
iodine rich brine or saltpeter with potassium carbonate.
Potassium iodide is available over the counter in most areas.
Like any other medication, you should talk to your doctor or pharmacist
before using it.
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