This ionizing radiation can damage DNA molecules directly, by breaking the bonds between atoms, or it can ionize water molecules and form free radicals, which are highly reactive and also disrupt the bonds of surrounding molecules, including DNA. If you stand in the way of those particles, they are going to interact with the cells of your body. You literally get a particle, an energy packet, moving through your cells and tissues.
Cells that are damaged less severely may survive and replicate, but the structural changes in their DNA can disrupt normal cell processes — like the mechanisms that control how and when cells divide. With ingested particles, some may pass through the body before they do much damage, but others linger, Dedon says. Radioactive iodine poses a particularly significant risk, because it is absorbed rapidly by the thyroid gland and held there.
That is why it is recommended that those who may be exposed to radioactivity in the air pre-dose themselves with iodine pills: the non-radioactive iodine is absorbed by the thyroid, which then does not absorb radioactive iodine if it comes along. Radiation injury is suspected when people develop symptoms of illness or skin redness or sores after receiving radiation therapy or being exposed during a radiation accident.
The time until symptoms develop can help doctors estimate the radiation dose. No specific tests are available to diagnose radiation exposure, although certain standard clinical tests may be used to detect infection, low blood counts, or organ malfunction. To help determine the severity of radiation exposure, doctors measure the number of lymphocytes Lymphocytes One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and Typically, the lower the lymphocyte count 48 hours after exposure, the worse the radiation exposure.
Swabs from the nose, throat, and any wounds also are checked for radioactivity. The early symptoms of acute radiation illness—nausea, vomiting, and tremors—can also be caused by anxiety. Because anxiety is common after terrorist and nuclear incidents, people should not panic when such symptoms develop, particularly if the amount of radiation exposure is unknown and may have been small.
Following widespread high-level environmental contamination from a nuclear power plant accident or the intentional release of radioactive material, people should follow the advice of public health officials. Such information is usually broadcast on TV and radio. The advice may be for people to evacuate the contaminated area or to take shelter where they are. Whether evacuation or sheltering is recommended depends on many factors, including time elapsed since the initial release, whether the release has stopped, weather conditions, availability of adequate shelters, and road and traffic conditions.
If sheltering is recommended, sheltering in a concrete or metal structure, particularly one below grade such as in a basement , is best. Halfway between the top and bottom of a tall building, near the center away from windows, is best when no below-grade shelter is available. A nuclear detonation near the ground produces a fireball that rapidly shoots up into the atmosphere and pulls up thousands of tons of dirt and debris. This creates the iconic mushroom-shaped cloud.
The cloud stabilizes in the upper atmosphere where radioactive material produced in the explosion mixes with the dirt and small particles of debris from the detonation. Fallout is the term for when these particles fall back to earth, collect on surfaces, and give off dangerous radiation.
Significant fallout can extend 10 to 20 miles from the blast. Going inside a building to shelter as far away from these particles is the best protective action. People have at least 10 to 15 minutes after the detonation to get inside before the fallout begins. Shelter in place as quickly as an effective shelter can be found for the first few hours after the detonation and then follow the advice of local emergency response officials.
After a radiation-releasing incident, whether evacuation or sheltering in place is recommended depends on many factors, including time elapsed since the initial release, whether the release has stopped, weather conditions, availability of adequate shelters, and road and traffic conditions.
Changing clothes and showering are recommended if people suspect they may have been contaminated with radioactive material.
People can obtain potassium iodide KI tablets from local pharmacies and some public health agencies. However, potassium iodide is only useful if radioactive iodine is released. It does not provide protection from other radioactive materials. People with known iodine sensitivity and certain thyroid conditions should avoid potassium iodide. A doctor should be consulted if iodine sensitivity is suspected.
Certain experimental drugs given during or immediately after irradiation have been shown to increase survival rates in animals. However, these drugs can be very toxic and are not currently recommended for people.
During imaging procedures that involve ionizing radiation and especially during radiation therapy for cancer, which involves high doses, the most susceptible parts of the body, such as the lenses of the eyes, female breasts, ovaries or testes, and thyroid gland, are shielded when possible for example, by wearing a lead-filled covering. People living within 10 miles 16 kilometers of a nuclear power plant should have ready access to potassium iodide tablets.
Changing clothes and showering with warm water and regular shampoo are very effective in removing most external contamination. The outcome depends on the radiation dose, dose rate how quickly the exposure occurs , and the parts of the body that are affected. Other factors include people's state of health and whether they receive medical care.
In general, without medical care, half of all people who receive more than 3 Gy of whole-body radiation at one time die. Nearly all people who receive more than 8 Gy die. Nearly all of those who receive less than 2 Gy fully recover within 1 month, although long-term complications such as cancer may occur.
With medical care, about half of people survive 6 Gy of whole-body radiation. Some people have survived doses of up to 10 Gy. Because doctors are unlikely to know the amount of radiation a person has received, they usually predict outcome based on the person's symptoms. The cerebrovascular syndrome is fatal within hours to a few days. The gastrointestinal syndrome generally is fatal within 3 to 10 days, although some people survive for a few weeks.
Many people who receive proper medical care survive the hematopoietic syndrome, depending on the radiation dose and their state of health.
Those who do not survive typically die within 4 to 8 weeks after exposure. Serious physical injuries are treated before irradiation is treated because they are more immediately life-threatening. Irradiation has no emergency treatment, but doctors closely monitor people for the development of the various syndromes and treat the symptoms as they arise. Contamination should be removed promptly to prevent the radioactive material from continuing to irradiate the person and to prevent the radioactive material from being taken up by the body.
Contaminated wounds are treated before contaminated skin. Doctors decontaminate wounds by flushing them with a salt water solution and wiping them with a surgical sponge. After decontamination, wounds are covered to prevent recontamination as other sites are washed.
Contaminated skin should be gently scrubbed with large amounts of warm not hot water and soap. Skin folds and nails need extra attention. Harsh chemicals, brushes, or scrubbing that may break the skin surface should be avoided. If hair cannot be decontaminated with soap and water, clipping it off with scissors is preferable to shaving. Shaving may cut the skin and allow contamination to enter the body.
Skin and wound decontamination should continue until the Geiger-Muller counter shows that the radioactivity is gone or almost gone, until washing does not substantially reduce the amount of radioactivity measured, or until further cleaning risks damaging the skin. Burns should be gently rinsed but not scrubbed. Certain measures can decrease internal contamination.
If people have recently swallowed a significant amount of radioactive material, vomiting may be induced. Some radioactive materials have specific chemical treatments that can reduce their absorption after being swallowed or help speed their removal from the body.
If administered shortly before or soon after internal contamination with radioactive iodine, potassium iodide very effectively prevents the thyroid gland from absorbing the radioactive iodine, thus reducing the risk of thyroid cancer and thyroid injury. Potassium iodide is effective only for radioactive iodine, not other radioactive elements.
Other drugs, such as zinc or calcium diethylenetriamine penta-acetate DTPA—for plutonium, yttrium, californium, and americium , calcium or aluminum phosphate solutions for radioactive strontium , and Prussian blue for radioactive cesium, rubidium, and thallium , can be given intravenously or by mouth to remove a fraction of certain radionuclides after they have entered the body.
Nausea and vomiting can be reduced by taking drugs to prevent vomiting antiemetics. Such drugs are routinely given to people undergoing radiation therapy or chemotherapy. Dehydration is treated with fluids given intravenously.
People with the gastrointestinal or hematopoietic syndrome are kept isolated to minimize their contact with infectious microorganisms. Extremely high doses can kill in days or weeks. The high-energy radiation given off by radioactive decay can take the form of very high speed particles electrons in the case of beta radiation; two protons and two neutrons in alpha radiation or waves gamma or X-rays. Regardless of the form it takes, all nuclear radiation has enough energy to strip electrons off atoms and molecules that it interacts with, earning it the name ionising radiation.
It is this electron-stripping ionising property that does the damage to our cells and tissues. As well as generating heat, the removal of electrons can break chemical bonds. When that happens in a molecule of DNA it can cause mutations, which can lead to cancer down the track. And ionising a protein can mess with its shape and function — not something you want in the molecules that coordinate most of the chemistry in our cells. Our bodies are full of water, and almost all cells have DNA, but some cells and tissues are more susceptible to damage from nuclear radiation than others.
The cells and organs that are most affected by nuclear radiation are the ones that are actively reproducing, because the DNA is more exposed when the cell is in the process of dividing.
Blood cells have the highest turnover rate in our bodies, so the tissue where they are produced — the rapidly dividing cells of the bone marrow — is the most susceptible to radiation damage. The damage to bone marrow in high doses — and complete destruction of it in very high doses — impairs our immune system by not replacing our white blood cells. Long-term exposure to lower doses can lead to cancerous DNA mutations in the marrow, which can lead to the blood cancer leukaemia in people exposed through work or location.
The cells lining the digestive system are also fast-dividing, so they can cope with the physical and chemical assault of digesting our food. Gastrointestinal damage contributes to the symptoms of acute radiation syndrome in people who are exposed to high doses. Developing foetuses are, of course, incredibly susceptible to radiation, while slow-dividing tissues like muscle and nerve cells are far less sensitive. And healthy tissues and organs are not the only cells that regularly reproduce — tumours are literally balls of cells that are dividing out of control, which is why radiation therapy can be effective in destroying them.
The good blood supply feeding tumours helps too, because the radiation interacts with the dissolved oxygen in the blood as well. That leads to the production of free radicals which attack the nearby cells, amplifying the radiation's effect. Exposure to external radiation is one thing, but ingesting radioactive particles takes the damage to another level. The severity of radiation sickness also depends on how sensitive the affected tissue is.
For instance, the gastrointestinal system and bone marrow are highly sensitive to radiation. The initial signs and symptoms of treatable radiation sickness are usually nausea and vomiting. The amount of time between exposure and when these symptoms develop is a clue to how much radiation a person has absorbed.
After the first round of signs and symptoms, a person with radiation sickness may have a brief period with no apparent illness, followed by the onset of new, more-serious symptoms. If you've had a mild exposure, it may take hours to weeks before any signs and symptoms begin.
But with severe exposure, signs and symptoms can begin minutes to days after exposure. An accident or attack that causes radiation sickness would no doubt cause a lot of attention and public concern. If such an event occurs, monitor radio, television or online reports to learn about emergency instructions for your area.
Radiation is the energy released from atoms as either a wave or a tiny particle of matter. Radiation sickness is caused by exposure to a high dose of radiation, such as a high dose of radiation received during an industrial accident. Radiation sickness occurs when high-energy radiation damages or destroys certain cells in your body. Regions of the body most vulnerable to high-energy radiation are cells in the lining of your intestinal tract, including your stomach, and the blood cell-producing cells of bone marrow.
Having radiation sickness can contribute to both short-term and long-term mental health problems, such as grief, fear and anxiety about:.
In the event of a radiation emergency, stay tuned to your radio or television to hear what protective actions local, state and federal authorities recommend.
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