- Posted March 15, 2011 by
Greater Los Angeles, California
Nuclear Radiation Exposure & Symptoms
Bleeding - from the nose, mouth, gums, and rectum - is one symptom of radiation sickness.
(CBS) The deepening nuclear crisis in Japan has some wondering if the release of dangerous radiation will cause a widespread medical calamity.
Radiation sickness: 8 terrifying symptoms
The U.S. Nuclear Regulatory Commission on Sunday said the U.S. faced little threat from radiation released in Japan in the aftermath of the March 11 earthquake and tsunami. "Given the thousands of miles between the two countries, Hawaii, Alaska, the U.S. Territories and the U.S. West Coast are not expected to experience any harmful levels of radioactivity," the agency said on its website.
But not everyone is feeling so reassured.
If fuel at a nuclear reactor melts down completely and breaches the reactor's containment vessel, it could cause a gigantic explosion as superheated fuel comes into contact with the water coolant. That's the word from Dr. Ira Helfand, a Massachusetts-based nuclear safety expert and past-president of Physicians for Social Responsibility.
"The fuel rods contain enormous amounts of radioactive material - each reactor can release more radiation than 1,000 Hiroshima-sized bombs," Helfand told CBS News in an email.
He said it's not clear just how far such radiation from such an accident would spread - and what the health consequences would be.
"At Chernobyl, it spread over large areas of Europe, and significant areas up to 100 miles downwind needed to be abandoned," he said, referring to the notorious 1986 nuclear accident. "But the conditions were somewhat different, and we aren't sure how far the radiation will be distributed this time."
People exposed to low levels of radiation face increased risk of cancer. In addition, they can pass on to their offspring genetic mutations that can cause birth defects.
Acute exposure to intense radiation can cause radiation sickness, a potentially deadly illness that triggers a range of terrifying symptoms, including vomiting blood.
What if you think you've been exposed to radiation? The Federal Emergency Management Agency recommends immediately changing your clothes and shoes, putting the exposed clothing in a sealed plastic bag, and then showering thoroughly.
If told to evacuate, the agency says, keep car windows and vents closed, and use recirculating air. If told to stay indoors, turn off the air conditioner and other air intakes and go to a basement. Do not use the telephone unless absolutely necessary.
Potassium iodide supplements can help curb the risk of cancer if taken just before or shortly after exposure, Dr. Helfand says, but should taken only with medical supervision.
This information was taken from the inter net:
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. A chronic radiation syndrome does exist but is very uncommon; this has been observed among workers in early radium source production sites and in the early days of the Soviet nuclear program. A short exposure can result in acute radiation syndrome; chronic radiation syndrome requires a prolonged high level of exposure.
Radiation exposure can also increase the probability of developing some other diseases, mainly cancer, tumours, and genetic damage. These are referred to as the stochastic effects of radiation, and are not included in the term radiation sickness.
The use of radionuclides in science and industry is strictly regulated in most countries. In the event of an accidental or deliberate release of radioactive material, either evacuation or sheltering in place are the recommended measures. For information on the effects of lower doses of radiation, see the article on radiation orders of magnitude.
Signs and symptoms
Radiation sickness is generally associated with acute (a single large) exposure. Nausea and vomiting are usually the main symptoms. The amount of time between exposure to radiation and the onset of the initial symptoms may be an indicator of how much radiation was absorbed, as symptoms appear sooner with higher doses of exposure. The symptoms of radiation sickness become more serious (and the chance of survival decreases) as the dosage of radiation increases. A few symptom-free days may pass between the appearance of the initial symptoms and the onset of symptoms of more severe illness associated with higher doses of radiation. Nausea and vomiting generally occur within 24–48 hours after exposure to mild (1–2 Sv) doses of radiation. Radiation damage to the intestinal tract lining will cause nausea, bloody vomiting and diarrhea. This occurs when the victim's exposure is 200 rems (1 Sv = 100 rems) or more. The radiation will begin to destroy the cells in the body that divide rapidly, including blood, GI tract, reproductive and hair cells, and harm the DNA and RNA of surviving cells. A direct quantitative relationship exists between the degree of the neutropenia that develops after exposure to radiation and the increased risk of developing systemic infection (sepsis). Headache, fatigue, and weakness are also seen with mild exposure. Moderate (2–3.5 Sv of radiation) exposure is associated with nausea and vomiting beginning within 12–24 hours after exposure. In addition to the symptoms of mild exposure, fever, hair loss, infections, bloody vomit and stools, and poor wound healing are seen with moderate exposure. Nausea and vomiting occur in less than 1 hour after exposure to severe (3.5–5.5 Sv) doses of radiation, followed by diarrhea and high fever in addition to the symptoms of lower levels of exposure. Very severe (5.5–8 Sv of radiation) exposure is followed by the onset of nausea and vomiting in less than 30 minutes followed by the appearance of dizziness, disorientation, and low blood pressure in addition to the symptoms of lower levels of exposure. Severe exposure is fatal about 50% of the time. Severe sepsis is the cause of death in most cases. See criticality accident for a number of incidents in which humans have been accidentally exposed to such levels of radiation.
Longer term exposure to radiation, at doses less than that which produces serious radiation sickness, can induce cancer as cell-cycle genes are mutated. The probability cancer will develop is a function of radiation dose. In radiation-induced cancer the disease, the speed at which the condition advances, the prognosis, the degree of pain, and every other feature of the disease are not functions of the radiation dose to which the person is exposed.
Since tumors grow by abnormally rapid cell division, the ability of radiation to disturb cell division is also used to treat cancer (see radiotherapy), and low levels of ionizing radiation have been claimed to lower one's risk of cancer (see hormesis).