KNOWLEDGE

KNOWLEDGE
Radioactivity facts
Radioisotopes, potential fuel for a "dirty bomb," serve many purposes in medicine, industry, agriculture and research and even in homes. Some are weak or used in minuscule amounts. Others rank as high risks. Here are some examples:
HIGHER RISK
Irradiators: Large devices that sterilize food, medical equipment or blood for transfusion. Irradiators are even used to enhance color in gemstones. Cobalt-60 or cesium-137.
Generators: Long-term power sources for remote equipment, such as lighthouses on Russia's Arctic coast or U.S. unmanned space probes. Strontium-90 or plutonium-238.
Radiotherapy: External-beam treatment or internal implanting of radioisotopes to kill cancer cells. Cobalt-60 or cesium-137.
Industrial radiography: Imaging of pipeline welds or the structure of steel or other light alloys to test for flaws. Iridium-192 or Cobalt-60.
LOWER RISK
Well logging: Devices to measure subsurface characteristics of oil and other wells. Cesium-137 or americium-241.
Gauging: Detectors that gauge density or thickness of material by measuring how much radioactivity penetrates. Cesium-137, cobalt-60 or americium-241.
Smoke detectors: Household devices in which minute radiation, when affected by smoke, sets off an alarm. Americium-241. Individual detectors pose no risk, but large stockpiles of americium at factories could.
Agriculture: Irradiation to sterilize pests, such as the medfly, to control populations. Cesium-137 or cobalt-60.
Source: Associated Press