Language of radiation at a glance
By Mary Manning
<manning@lasvegassun.com>
Las Vegas SUN  January 24, 1999

While we live in a world bathed naturally in radiation, since the first atomic bomb exploded into the skies of Alamogordo, N.M., on July 16, 1945, scientists have warned about exposing people to too much extra radioactivity.
Nuclear-weapons testing worldwide and nuclear reactors, plus medical X-rays, add to radiation exposure above the amount received from the Earth and cosmic rays from space, which is considered natural background radiation.
Las Vegans receive a daily average dose of radiation from the sun of about 6 millirems. Exposure to an X-ray is about 10 millirems. Atoms are the basic building blocks of all matter. Unstable atoms that decay within a fraction of a second to billions of years are called radionuclides. The rate of decay is known as a half-life, or the time it takes half the radioactive atoms to decay.
For example, plutonium has a half-life of 24,000 years; uranium-238 rates a half-life of 4.5 billion years; tritium has a half-life slightly of more than 12 years. Nuclear bombs are designed to bring together a large amount of atoms together so they split, creating energy, in a process called fission. The fissionable materials create a chain reaction that rapidly consumes the material and explodes.
Radiation takes three forms:
* GAMMA: Has the greatest penetrating power of the three types. Humans must be shielded from it by lead or a thick concrete barrier. Exposure to gamma radiation can damage organs in the body. Most fission products emit both gamma and beta radiation. Cesium-137 is an example of a gamma-emitter.
* BETA: Can be blocked by wood or aluminum. Beta radiation causes the most damage if its
particles are ingested or inhaled, or if the radioactive materials come in contact with skin. Tritium and strontium-90, which seeks the bones in the human body, emit beta radiation.
* ALPHA: The least penetrating type of radiation. It can be blocked by a sheet of paper and cannot penetrate or burn intact human skin. But it is harmful if swallowed or inhaled. Plutonium emits alpha radiation, which is why it is dangerous if inhaled or ingested.
The sun emits all three types of radiation.
The way scientists measure radiation is by a unit called a curie. The curie is a traditional unit of radioactivity equal to the radioactivity of 1 gram of pure radium. The curie is named after Pierre and Marie Curie, who discovered radium in their Paris laboratory.

Sources: The League of Women Voters "Nuclear Waste Primer" and The Institute for Energy and
Environmental Research's "Plutonium: Deadly Gold of the Nuclear Age."
 http://www.lasvegassun.com/sunbin/stories/text/1999/jan/24/508316297.html
 [DOEWatch] Digest Number 230     25 Jan 1999 11:46:11 -0000
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Uranium and Health

One of the pamphlets that never completed by the original RGNNS groups was on health effects of uranium mining. This will take some time.

History of Saskatchewan Uranium Mining

RADIOACTIVITY
1.Natural Radioactivity NORM
2.Radioactive Series
3.Calculation of Activity
4.Activity of Uranium Ore
5.Activity of Natural Uranium
6.Enriched and Depleted Uranium
7.Activity of Depleted Uranium
8 Fission of uranium, Plutonium, Spent Fuel

RADIOLOGICAL EFFECTS
1.Radiation Dose Equivalent
2.Regulatory Limits on Radiation Exposure
3.External and Internal Exposure to Uranium
4.Radiological Limits on Uranium Intake
5.DU Penetrator Impact Studies
7.Animal and Radiation Worker Studies

CHEMICAL TOXICITY
1.Uranium Effects on Kidney
2.Uranium Excretion and Deposition in Organs
3.Toxicological Limits on Uranium Intake
4.Gulf War Exposure to Uranium
5.Chronic Exposure to Uranium
6.Cancer Development Caused by DU

References:

URANIUM: RADIATION PROTECTION GUIDELINES, NCRP Draft Report
No. SC 57-15  <http://www.ncrp.com/sc57-15.pdf>  (674K PDF format)

Review of Radioactivity, Military Use, and Health Effects of Depleted Uranium
Compiled by Vladimir S. Zajic, July 1999 <A
HREF="http://members.tripod.com/vzajic/contents.html">
http://members.tripod.co
m/vzajic/contents.html</A>

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Health effects
To understand the health effects of uranium or radiation, one must look at the source and pathways through which uranium or radiation works.

 The health hazards of uranium are due to 2 properties:  radiation and toxicity. These effects are applied through a variety of pathways and occur from the natural decay of uranium or from fission products. Fission products are produced in nuclear explosions or power reactors.

Radiation of 3 different type from uranium and it's decay products. Natural decay and fissioning of uranium produce these effects. The radiation takes three forms:
* GAMMA: Has the greatest penetrating power of the three types. Humans must be shielded from it by lead or a thick concrete barrier. Exposure to gamma radiation can damage organs in the body. Most fission products emit both gamma and beta radiation. Cesium-137 is an example of a gamma-emitter.
* BETA: Can be blocked by wood or aluminium. Beta radiation causes the most damage if its
particles are ingested or inhaled, or if the radioactive materials come in contact with skin. Tritium and strontium-90, which seeks the bones in the human body, emit beta radiation.
* ALPHA: The least penetrating type of radiation. It can be blocked by a sheet of paper and cannot penetrate or burn intact human skin. But it is harmful if swallowed or inhaled. Plutonium emits alpha radiation, which is why it is dangerous if inhaled or ingested.
The sun emits all three types of radiation. The atmosphere blocks a lot of the effects.
 
The way scientists measure radiation is by a unit called a curie. The curie is a traditional unit of radioactivity equal to the radioactivity of 1 gram of pure radium. The curie is named after Pierre and Marie Curie, who discovered radium in their Paris laboratory.

Radiation causes cell damage. The cells can repair some damage however damage is cumulative and may not show up until later as cancer, aging effects, genome damage, etc. Small amounts of radiation actaullay stress the body with a homeostasis effect. The body seems to like some stress. However this really should not be confused with radiation is good for you. Radiation is a big topic in itself.

Toxic effects would be from heavy metal poisoning as Uranium is a heavy metal. Other substances with the ore like lead and arsenic are also present. These can cause kidney or nerve damage with a direct toxic effects and chronic stress to the body.

Pathways are how the radiation effects get into your body.

Direct effects typically come from gamma radiation. If you walk across a high grade ore body you get gamma rays just like a chest X-ray  equivalent to about one or more  per hour.  Direct effects also come from the decay products of radon gas or it's daughters. These can be from Alpha and beta and gamma radiation. If you breathe the radon gas this would be absorbed through the lungs. If a radon gas particle decays it may get stuck in the lungs as a solid particle which will decay at a future time giving a close hit of radiation to the lung tissue durring a decay process. This may show up as lung cancer later.

If you absorb the uranium or it's decay products, these accumulate and get's tied up with the calcium chemistry in the body. The  substances seek the bones particularly the outside surface.This is common for most other heavy metals. At a future time if uranium decays, radiation is given off effecting  cells of the body at the surface of the bones.

Uranium also has effects from it's decay series and these will occur due to the various decay elements found in various quantities after decay. Fission decay producst are also presnt in the environment form atmospheric testing of nukes and commercial power reactors.

Uranium is extremely dense and well suited for military use. Uranium also burns at 500 C and vapurizes into aerosols which can   enter the lungs.

It is also important to undersatnd the chemistry of uranium. The  main isotopes of uranium are:

Uranium-232 Not found in natural uranium. Only after uranium has been used in Nuclear reactor. Very little ie. 0.00 % remains.

Uranium-233 Not found in natural uranium. Only after uranium has been used in Nuclear reactor. Very little ie. 0.00% remains.

  Uranium-234 Found in natural uranium .005%

  Uranium-235 The "best" part of uranium. When enriched (concentrated) can be used in nuclear weapons. Found in natural uranium 0.7% Under goes fissioning easily therefore useful in weapons and light water reactors. Easier to work with you might say. as the nuclear reaction will happen with little effort.

  Uranium-236 Not found in natural uranium. Only after uranium has been used in Nuclear reactor. 0.2% os found.

  Uranium-237 Not found in natural uranium. Only after uranium has been used in Nuclear reactor. Very little ie. 0.00% remains

  Uranium-238 Common natural uranium found in the most abundant quantity. 99.3% Used in heavy water reactors like the Candu

Depleted uranium consists of the "remains" after the best part U-235 has been removed. If used reactor fuel has been recycled to recover the unused u-235 then the waste depleted uranium will contain small quantities of all uranium isotopes and even plutonium 239.

Wherever you find U-238 you wiill find all the 14 radioactive daughters of U 238. The quantities will vary based on whether the uranium is in natural ore, natural uranium, enriched uranium, spent fuel or depleted uranium. Even natural uranium will have some quantity as the uranium on earth was undergoing some fission reactions durring the creation of the earth
 
 
 

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