James > I am a former Airman in the US Air Force. We were required at all times to wear small devices around our neck that detected the presence of radioactivity for our protection. Surely, all soldiers in a war zone would wear these badges also.
Yes, I'm familiar with those radiation detectors. Radiographers also wear them. Actually, they are only pieces of unexposed photographic film which slowly become "exposed" depending on the amount of radiation to which the wearer has become "exposed". But do they actually do what they purport to do? In other words, is the safe level of radiation actually safe?
ccnr.org
>>>"Our limits admit that any dose can increase the risk and, on that premise, cancer deaths are not unexpected." He added that "studies say the average risk under these limits is comparable to the risk in an industry with a high safety standard -- for example, manufacturing shoes."
A spokesman for Ontario Hydro, Richard Furness, said in an interview with the Toronto Star that "no one has ever died or suffered lost-time injuries due to radiation at a Hydro nuclear plant -- or any other Canadian nuclear facility." When told about the AECL acknowledgement of two cases at Chalk River, Furness remarked: "Oh. Well, there goes that record."
Ontario Hydro's Health and Safety Director Bob Wilson said it was time the public recognized the facts. For every hundred million hours of work done under radiation exposure (at no more than the permissible limits) about 2 to 4 otherwise unexpected cancer cases will develop, Wilson said. "We have never said a radiation worker is without risk," he insisted, but added that radiation workers are 10 to 100 times less likely to die from work than such people as fishermen, forestry workers, miners or even Hydro linemen.
But a well-informed AECL worker told the Toronto Star that "this is going to open an intense debate about safety. What can we expect from all the other live or dead cancer victims who have long-term low-level radiation exposure at AECL or Ontario Hydro? It could mean that the whole system of predictions that five rems of radiation was an acceptable dose for workers is dead wrong."
Critics of the nuclear industry have argued that the industry's predictions could prove fatally wrong for many more workers than anticipated. It can take 20 years or more for cancers to develop from low-level long-term radiation exposure, and at least 250 Hydro workers and about the same number at AECL are coming up for the 20-year turning point.<<<
> This story about depleted uranium poisoning sounds terrible but I wonder how much basis in truth it contains.
It's true all right.
ccnr.org
>>>... there are several important military uses for depleted uranium {in conventional warfare]:
a. when used to coat conventional bullets and shells, it makes them armour-piercing;
b. when used as a metallic alloy in tanks and other vehicles, it provides armour-plating.
ccnr.org
>>>There is no dispute of the fact that at least 320 tons of depleted uranium (DU) was "lost" in the Gulf war, and that much of that was converted at high temperature into an aerosol, that is, minute insoluble particles of uranium oxide, UO2 or UO3 , in a mist or fog. It would have been impossible for ground troops to identify this exposure if or when it occurred in war, as this would require specialized detection equipment. However, veterans can identify situations in which they were likely to have been exposed to DU. Civilians working at military bases where live ammunition exercises are conducted may also have been exposed.
Uranium oxide and its aerosol form are insoluble in water. The aerosol resists gravity, and is able to travel tens of kilometres in air. Once on the ground, it can be resuspended when the sand is disturbed by motion or wind. Once breathed in, the very small particles of uranium oxide, those which are 2.5 microns [ one micron = one millionth of a meter ] or less in diameter, could reside in the lungs for years, slowly passing through the lung tissue into the blood. Uranium oxide dust has a biological half life in the lungs of about a year. According to British NRPB [ National Radiation Protection Board ] experiments with rats, the ceramic or aerosol form of uranium oxide takes "twice as long" or about a two year biological half life in the lungs, before passing into the blood stream. [Stradling et al 1988]
Because of coughing and other involuntary mechanisms by which the body keeps large particles out of the lungs, the larger particles are excreted through the gastro-intestinal tract in feces. The uranium compounds which enter the body either through the wall of the gastro-intestinal tract or the lungs, can be broken down in the body fluids, and tetravalent uranium is likely to oxidize to the hexavalent form, followed by the formation of uranyl ions. Uranium generally forms complexes with citrate, bicarbonates or protein in plasma, and it can be stored in bone, lymph, liver, kidney or other tissues. Eventually this uranium which is taken internally is excreted through urine. Presence of depleted uranium in urine seven or eight years after exposure is sufficient evidence to substantiate long term internal contamination and tissue storage of this radioactive substance.
Uranium is both a chemical toxic and radioactive hazard: Soluble uranium is regulated because of its chemical toxicity, measured by damage to the kidney and tubules. Uranium is a heavy metal, known to cause uranium nephritis. Insoluble uranium, such as was released in the Gulf War, is regulated by its radiological properties, and not its chemical properties. Because of its slow absorption through the lungs and long retention in body tissues, its primary damage will be due to its radiological damage to internal organs rather than chemical damage to the renal system. Obviously, both types of damage occur simultaneously, therefore it is a matter of judgment which severe damage, radiological or chemical, occurs at the lowest dose level. However, with the lengthening of the time during which the contaminant resides in the body and the low overall dose, the risk of cancer death becomes greater than the risk of significant damage to the renal system.<<< |
