Radiation is a type of energy, emitted in rays or tiny particles, according to MedlinePlus. People are exposed to small doses of radiation every day from sources like sunshine or through diagnostic tests, like X-rays. This occasional exposure to low levels radiation is harmless. If a person were exposed to a large amount of radiation, or exposed to this radiation for a long period of time, he could suffer permanent damage to his body or even death.
Causes
Lengthy exposure to large amounts of radiation is very dangerous but uncommon. Lethal doses of radiation could be caused by a leak from a nuclear power plant, like the 1986 leak at the Chernobyl plant in the Ukraine where 30 people succumbed to radiation poisoning. Other causes of radiation exposure might be the detonation of a dirty bomb or fallout from a nuclear bomb.
Dosages
The severity of symptoms and mortality rate depend on how much radiation was absorbed into the body and for how long. This absorbed radiation is measured in units called a gray, or Gy, according to MayoClinic.com. The radiation absorbed in the typical X-ray is 0.1 Gy. A patient with an exposure of 1 Gy may begin to feel symptoms of radiation sickness. An exposure of 6Gy is considered lethal; the patient typically dies two days to two weeks after exposure.
Symptoms
Symptoms may come in two waves after exposure to radiation. The first wave may come within six hours after a mild exposure and within minutes for very severe exposure to radiation. The person may first experience nausea and vomiting and then, if exposure was strong enough, may begin to complain of diarrhea, headache and fever. Patients may often have a short period without any symptoms at all, especially if exposure to radioactive material was mild.
Depending on the strength and length of exposure, a second wave of symptoms may begin to appear immediately or within several weeks of exposure. These symptoms include dizziness, weakness and fatigue. More severe symptoms such as hair loss, bloody vomit and stools, infections and low blood pressure may arise for those individuals who were exposed to potentially lethal doses of radiation.
Health Effects
Radiation affects the atoms in the body by causing them to ionize, or splitting one atom into two ions. Radiation can also break chemical bonds between atoms, according to the Environmental Protection Agency. The body attempts to repair the damage but sometimes the damage is too severe or widespread. In other cases, the repairs themselves can lead to cancerous growths.
A patient may suffer effects from radiation weeks or years after exposure. These conditions may be as mild as skin reddening, or as severe as cancer. Cancer is the primary health effect caused by exposure to radiation. Risk of birth defects are increased if a pregnant woman is exposed to radiation, and her baby has an increased risk for developing cancer later in life, according to the Centers for Disease Control and Prevention.
Radiation Therapy
Not all exposure to radiation is detrimental to the body. Radiation is most harmful to rapidly growing cells, according to MedlinePlus. Since cancer is defined by the rapid growth of abnormal cells, radiation therapy is effective at destroying cancer cells.
