MANILA, Philippines—Radioactivity, or radioactive decay, is the spontaneous emission of energy from unstable atoms. These atoms emit radiation, which travels in the form of waves or high-speed particles.
Radiation poisoning, radiation sickness or a creeping dose, is a form of damage to organ tissue caused by excessive exposure to ionizing radiation. The term is generally used to refer to acute problems caused by a large dosage of radiation in a short period, though this also has occurred with long term exposure. The clinical name for radiation sickness is acute radiation syndrome (ARS) as described by the CDC
Everyone is exposed to low levels of radiation on a daily basis, as radiation occurs naturally in sunlight and sound waves. Man-made radiation is used in X-rays, nuclear weapons, nuclear power plants and cancer treatment.
The amount and duration of radiation exposure affects the severity or type of health effect. Any living tissue in the human body can be damaged by radiation in a certain manner, but the body can also repair its own cells and leave no residual damage.
But sometimes, if the exposure is too long or the radiation too high, the damage becomes too severe or widespread to be repaired.
For example, exposure to small amounts of UV radiation is beneficial for people and essential in the production of vitamin D and in the treatment of several diseases, such as jaundice.
Signs and symptoms
But prolonged exposure to UV radiation may result in skin cancer and cataracts.
Other long-term health effects of damaging radiation exposure are mutations that affect fetuses or unborn children (smaller head or brain size, poorly formed eyes, abnormally slow growth, and mental retardation) and genetic effects that are passed from parent to child.
Exposure to a lot of radiation during a short period, such as from a radiation emergency, can cause burns or radiation sickness. Symptoms of radiation sickness include nausea, weakness, hair loss, skin burns, and reduced organ function.
Large enough exposure can cause premature aging or even death.
Prevention
The best prevention for radiation sickness is to minimize the dose suffered by the human, or to reduce the dose rate. What you can can do to avoid radiation poisoning is to stay inside when fallout is expected, shower and change your clothes when you come in from outdoors and listen for announcements by officials in case the situation changes.
Principles of radiation protection
Time: Reducing the time of an exposure reduces the effective dose proportionally. An example of reducing radiation doses by reducing the time of exposures might be improving operator training to reduce the time they take to handle a source.
Distance: Increasing distance reduces dose due to the inverse square law. Distance can be as simple as handling a source with forceps rather than fingers.
Shielding: The term 'biological shield' refers to a mass of absorbing material placed around a reactor, or other radioactive source, to reduce the radiation to a level safe for humans
Q: Is soap and water really enough to get radiation off you? A: Any person with contamination on their clothing or body should remove their clothes and shower. Soap and water can go a long way toward minimizing absorption through the skin and keeping local contamination from spreading.
Q: Iodine tablets are selling out in America; should we be stocking up? Are there any other steps we should take
A: There is absolutely no need to panic and right now and there are no special steps that experts are recommending. After a nuclear event, local public health or emergency management officials will tell the public if they should be taking potassium iodide or if other protective actions are needed. Remember, iodine prophylaxis is not one size fits all. If you have a seafood or shellfish allergy, a thyroid condition or certain skin disorders, you should not take potassium iodide before consulting with your doctor.
Governments world-wide are now stockpiling potassium iodide (KI). The CDC recommends using iodine to prevent injury form radioactive iodine fallout.
Sources: "Radioactivity and Radiation" (US Environmental Science Division), "Radiation Exposure" (US National Library of Medicine), US Environmental Protection Agency
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