Radiation injury (patient information)

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Associate Editor-in-Chief: Lakshmi Gopalakrishnan, M.B.B.S.; Varun Kumar, M.B.B.S.

What is radiation?

Radiation is a form of energy. The unit for measurement of radiation released into the environment is "curies", while the amount of radiation a person receives is measured as "rem".

What are the causes for radiation exposure?
 * People are constantly exposed to radiation both from natural sources (cosmic rays from the sun) and man-made sources including electronic equipment (microwave & television), medical sources (X-rays) and from nuclear weapon testing. However, the amount of radiation from the natural or man-made sources is usually small while a radiation emergency (such as nuclear power plant accident or a terrorist event), depending on the situation could expose people to small or large doses of radiation.


 * Scientists estimate that the average person in the United States receives a dose of about one-third of a rem per year. About 80% of human exposure comes from natural sources and the remaining 20% comes from man-made radiation sources – mainly medical x-rays.


 * Exposure levels in rem Dose:
 * One dental x-ray 4 = 15 mrem exposure
 * One chest x-ray = 10 mrem exposure
 * One mammogram = 70 mrem exposure
 * One year of exposure to natural radiation (from soil, cosmic rays, etc.) = 300 mrem exposure

This contamination could be internal (taken into the body through breathing, eating, or drinking) or external (such as radiation energy penetrating the body).
 * Contamination refers to radioactive particles getting deposited anywhere that they are not supposed to be (as on an object or on a person’s skin).

What are the effects of radiation?
 * The adverse health effects of radiation depends on the dose of radiation exposed.
 * Radiation sickness is acute exposure with a dose greater than 75 rads of penetrating radiation to the body in a short time (usually minutes). A characteristic set of symptoms occur in an orderly manner depending on the type,route and amount of radiation absorbed by the body. The earliest symptoms are nausea, fatigue, vomiting, and diarrhea. Hair loss, bleeding, swelling of the mouth and throat, and general loss of energy may follow. If the exposure has been approximately 1,000 rads or more, death may occur within 2 – 4 weeks.
 * Longer term exposure to radiation at low doses, produce serious radiation sickness by inducing cancer as the cell-cycle genes are mutated.

How can I be prepared for radiation emergency?
 * Contact your community leaders and employers to learn about the the plan and possible evacuation routes during radiation emergencies.
 * Develop your own emergency plan for your family.
 * Prepare a family emergency kit which should include:
 * Canned and packed food
 * Bottled water
 * Manual can opener
 * A flashlight with extra batteries
 * A portable radio with extra batteries
 * A first-aid kit with essential prescription medications
 * Paper towels, garbage bags, toilet paper and other personal items.

How can I protect myself in the event of radiation emergency?
 * Tune to the local news station for information and instructions during any emergency.
 * If there is release of large amount of radioactive particles into the environment as in nuclear explosion or a nuclear reactor accidents, you many be advised to evacuate or to stay indoors.
 * If you are advised to stay indoors, you should do the following:
 * All the doors and windows should be locked.
 * Air conditioners, fans and heating units that bring in air from outside should be turned off.
 * Fireplace dampers should be closed.
 * Should be tuned to local news station or emergency response network further instructions.
 * If you are advised to evacuate, follow the instructions provided by local officials and leave the area as quickly and orderly as possible and carry the emergency kit mentioned above.

What is the treatment for radiation emergency due to nuclear power plant accident or nuclear explosion?

Nuclear reactor accidents release radioactive iodine which as a part of internal contamination enters the human body. Within the body the radioactive iodine is absorbed by the thyroid gland and subsequently injuries the gland. The radioactive iodine usually clears off from the environment within 24hours.


 * Potassium iodide(KI) is a non-radioactive salt of stable iodine that blocks the uptake of radioactive iodine into the thyroid gland as the gland becomes “full” and cannot absorb any more iodine (either stable or radioactive) for next 24 hours.However KI does not prevent the radioactive iodine from entering the body or prevent the damage caused by radioactive substance to other parts of the body.


 * Iodized table salt also contains iodine but does not contain enough to block radioactive iodine uptake into the thyroid gland.

When do you start taking potassium iodide?

After a nuclear event, the local public health or emergency management officials announce the amount of radiation occurred and further precautions to be taken. Potassium iodide is recommended only to those internally contaminated with (or likely to be internally contaminated with) radioactive iodine, unless they have known allergies to iodine.

Children are more sensitive to effects of radioactive iodine than adults.

Who should take potassium iodide?


 * Newborn to 18years (including breast-fed infants)
 * Young adults (between 18 – 40 years)
 * Pregnant woman (all forms of iodine cross placenta, hence KI is required to protect the fetus).
 * Breastfeeding women - CDC recommends that women internally contaminated with or are likely to be internally contaminated with radioactive iodine stop breastfeeding and feed the child baby formula as the radioactive iodine quickly enters breast milk, but if breast milk is the only food available for the infant then nursing to be continued.
 * People with hypothyroidism

Adults older than 40 years have the least chance of developing thyroid cancer and higher chance of developing allergic reactions to KI, hence should not take KI unless exposed to a very large dose of radioactive iodine.

Who should not take potassium iodide?
 * Known allergy to iodine
 * Known Hyperthyroid states should take KI under supervision
 * Skin disorders such as urticaria vasculitis, dermatitis herpetiformis

What are the possible risks and side effects of KI?

Following a nuclear event, when the public health or emergency management officials announce the public to take KI, the benefits of taking KI outweighs the risk which is true for all age groups. Common side effects are :
 * Allergic reactions (higher incidence in adults older than 40)
 * Salivary gland inflammation
 * Inflammation of the salivary glands
 * Thyroid gland injury (with higher KI dose or taken for several days)
 * Newborns(less than 1 month old) develop hypothyroidism if more than one dose is given and untreated hypothyroidism causes brain damage. Hence infants should receive KI under constant supervision.