Radiation poisoning
Radiation poisoning, also called "radiation sickness", is damage to the human (or other animal) body from 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. Many of the symptoms of radiation poisoning occur as ionizing radiation interferes with cell division. This interference causes particular problems for otherwise normally rapidly dividing cells, such as those lining the gastrointestinal tract.The symptoms of radiation sickness become more serious (and the chance of survival decreases) with as the dosage of radiation increase. Exposure dosages are nowadays usually stated in Sieverts (Sv). 1 Sv equals 100 remss or 100 rads.
The symptoms of radiation poisoning include skin burns, fainting, fatigue, diarrhea, nausea, vomiting, hair loss, and at high dosages, death. An extremely high dose of radiation to the whole body, such as 100 Sv (10,000 remss) in a short period will cause unconsciousness and death as nerve cells are destroyed. A smaller (but still high) dosage will cause immediate severe illness, after which the victim will appear to recover, only to die within days as the rapidly dividing intestinal cells fail.
Exposure to 5 Sv (500 rems) in a short period is fatal within a few days in approximately half the cases. If the victim survives the next few weeks, he or she is likely to recover, but will face an increased chance of cancer.
Chronic exposure to radiation can lead to leukemia and other cancers. Ironically, the ability of radiation to disturb cell division is also used to treat cancer (see radiotherapy).
Radiation poisoning can result from accidental exposure to natural or industrial radiation sources. People working with radioactive materials often wear film "badges" or other dosimeters to monitor their total exposure to radiation. These devices are more apropos than Geiger counters for determining biological effects, as they measure cumulative exposure over time, and are calibrated to change color otherwise signal the user before exposure reaches unsafe levels.
Radiation poisoning caused illness and death after the bombings of Hiroshima and Nagasaki and downwind of the atmospheric testing of the 1950s, and was a major concern after the Chernobyl reactor accident.
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Declassified U.S government documents indicate ranges of exposure levels and their corresponding symptoms (note that, for obvious reasons, there has been no intensive testing under laboratory conditions, so symptoms may vary with different people):
5 - 20 rad (0.05 - 0.2 Sv) No symptoms. Likely long-term consequences: cancer, mutation of genetic material.
20 - 50 rad (0.2 - 0.5 Sv) No noticeable symptoms. Number of erythrocytes decreases temporarily.
50 - 100 rad (0.5 - 1 Sv) Mild radiation sickness with headache and increased risk of infection. Temporary male sterility is possible.
100 - 200 rad (1 - 2 Sv) Light radiation poisoning, 10% fatality after 30 days (LD 10/30). Typical symptoms include mild to moderate nausea (50% probability at 200 rad), with occasional vomiting, beginning 3 to 6 hours after irridation and lasting for up to one day. This is followed by a 10 to 14 day anastasis, after which light symptoms like general illness, anorexia and fatigue (50% probability at 200 rad). The immune system is depressed, with convalescence extended and increased risk of infection. Temporary male sterility is common.
200 - 300 rad (2 - 3 Sv) Severe radiation poisoning, 35% fatality after 30 days (LD 35/30). Nausea is common (100% at 300 rad), with 50% risk of vomiting at 280 rad. Symptoms onset at 1 to 6 hours after irridation and last for 1 to 2 days. After that, there is a 7 to 14 day anastasis, after which the following symptoms appear: loss of hair all over the body (50% probability at 300 rad), fatigue and general illness. There is a massive loss of leukocytes, greatly increasing the risk of infection. Permanent female sterility is possible. Convalescence takes one to several months.
300 - 400 rad (3 - 4 Sv) Severe radiation poisoning, 50% fatality after 30 days (LD 50/30). As with 300 to 400 rad dosage, with uncontrollable bleeding in the mouth, under the skin and in the kidneys (50% probability at 400 rad) in the post-anastatic period.
400 - 600 rad (4 - 6 Sv) Acute radiation poisoning, 60% fatality after 30 days (LD 60/30). Fatality increases from 60% at 450 rad to 90% at 600 rad (unless there is intense medical care). Symptoms start half an hour to two hours after irridation and last for up to 2 days. After that, there is an 7 to 14 day anastasis, after which generally the same symptoms appear as with 300 to 400 rad irridation, with increased intensity. Female sterility is common at this point. Convalescence takes several months to a year. The primary causes of death (in general 2 to 12 weeks after irridation) are infections and internal bleeding.
600 - 1000 rad (6 - 10 Sv) Acute radiation poisoning, 100% fatality after 14 days (LD 100/14). Survival depends on intense medical care. Bone marrow is nearly or completely destroyed, so a bone marrow transplantation is required. Gastric and intestinal tissue are severely damaged. Symptoms start 15 to 30 minutes after irridation and last for up to 2 days. Subsequently, there is a 5 to 10 day anastasis, after which the person dies of an infection or internal bleeding. Recovery would take several years and probably never be complete.
1000 - 5000 rad (10 - 50 Sv) Acute radiation poisoning, 100% fatality after 7 days (LD 100/7). A dose this high leads to spontaneous symptoms after 5 to 30 minutes. After powerful fatigue and immediate nausea caused by direct activation of chemical receptors in the brain by the irridation, there is a period of several days of comparable well-being, called the "walking ghost phase". After that, cell death in the gastric and intestinal tissue, causing massive diarrhea, intestinal bleeding and loss of water, leads to water-electrolyte imbalance. Death sets in with delirium and coma due to breakdown of circulation. Death is inevitable; the only treatment that can be offered is pain therapy.
more than 5000 rad (>50 Sv). Immediate disorientation and coma in seconds or minutes. Death sets in after a few hours by total collapse of nervous system.
more than 8000 rad (>80 Sv). U.S. military forces expect immediate death at a dose above 8000 rad.Table of Exposure Levels and Symptoms