Radiation poisoning

Radiation poisoning, also called "radiation sickness", is a form of damage to organic tissue due to 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 cells that normally divide rapidly, such as those lining the gastrointestinal tract. Likewise, this is one reason for the effectiveness of radiotherapy in treating cancer — cancer cells are among the fastest-dividing in the body, and will be killed by a radiation dose that adjacent normal cells are likely to survive.

Symptoms and Effects

The symptoms of radiation sickness become more serious (and the chance of survival decreases) as the dosage of radiation increases. Prolonged exposure to radiation can induce cancer as cell-cycle genes are corrupted. However, since tumors themselves 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).

Related Topics:
Cancer - Tumors - Radiotherapy - Ionizing radiation - Hormesis

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

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 useful than Geiger counters for determining biological effects, as they measure cumulative exposure over time, and are calibrated to change color or otherwise signal the user before exposure reaches unsafe levels.

Related Topics:
Dosimeter - Geiger counter

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Radiation caused illness and death after the bombings of Hiroshima and Nagasaki in about 1% of those exposed who survived the initial explosions. The casualty rate due to radiation was higher in Hiroshima, because although Fat Man (the bomb used at Nagasaki) had a higher yield than Little Boy (the bomb used at Hiroshima), Fat Man was a plutonium weapon, which is actually much less radioactive than a uranium weapon of equal yield (except at the moment of critical mass). Both bombs were airbursted, minimizing nuclear fallout (which otherwise would have killed many more).

Related Topics:
Hiroshima - Nagasaki - Fat Man - Little Boy - Plutonium - Uranium - Nuclear fallout

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Radiation poisoning also continues to be a major concern after the Chernobyl reactor accident. Of the 100 million curies (4 exabecquerels) of radioactive material, the radioactive xenon-133 and iodine-131 Chernobyl released were initially the most dangerous. Due to their short half-lives they have now (2004) decayed, leaving the more long-lived caesium-137 (with a half-life of 30.07 years) and strontium-90 (with a half-life of 28.78 years) as main dangers. Thirty-one people died as an immediate result of the Chernobyl accident.

Related Topics:
Chernobyl - Curie - Exabecquerels - Xenon - Iodine - Caesium - Strontium

~ ~ ~ ~ ~ ~ ~ ~ ~ ~