There's been quite a bit of fear about
radiation exposure due to the recent nuclear disaster in Japan. This has
apparently caused folks on the West Coast of the U.S. to experience some panic
about their risk for thyroid cancer and has led to their taking potassium
iodide tablets. In fact, people on the West Coast are not facing an
increased risk of thyroid cancer at this time. And by taking large amounts of
iodine, people over the age of 40 may develop an underactive thyroid gland (hypothyroidism). The
key word here is "excessive" exposure.
Acute effects: radiation poisoning or
The dose of radiation exposure
determines the type of symptoms and the time of their onset. Even relatively
low doses of radiation may be accompanied by the rapid onset of nausea,
vomiting, skin reddening, tiredness, and fever. Larger doses can cause rapid
death. Intermediate amounts of exposure can result in the symptoms of radiation
sickness over a period of several months. These symptoms result from:
Bone marrow damage which leads to infections from low white
blood cells, bleeding from low blood platelets, and tiredness from decreased
red blood cells.
Damage to the gastrointestinal tract
may cause nausea, vomiting, abdominal pain, and loss of appetite.
Effects on the nervous system which include diminished
consciousness, headache, and dizziness.
Skin irradiation leads to extreme reddening, blisters, and
Supportive measures, such as blood
transfusions and antibiotics, are the only treatment options for radiation
Chronic effects of lower doses of
Exposure to radiation can produce
genetic damage and increase the risk of both malignant and benign tumors.
Except for avoiding radiation exposure, the only possible preventive measure is
to protect against thyroid cancer. The thyroid gland concentrates dietary
iodine and uses it to make thyroid hormones; and radioactive iodine is one of
the byproducts of a nuclear explosion. Because the thyroid is extremely
sensitive to radiation, uptake of large amount of radioactive iodine can result
in benign nodules and thyroid cancer. The risk is greatest for younger
individuals. Administration of potassium iodide tablets immediately after
a massive exposure to radioactive iodine can block its uptake and protect
against thyroid cancer. Daily administration of iodide pills can also
protect against chronic exposure to radioactive iodine.
Only one way to avoid effects
The bottom line: limiting exposure to
radiation is the only way to completely avoid both its acute and long-term ill
effects. Even so, the radiation being released into the atmosphere from the
nuclear plant in Japan is not considered a health hazard here in the U.S. This
is because the average person gets much more radiation exposure from natural
sources such as cosmic radiation from the sun and outer space, ground rocks and
dirt, and even from some foods and water.