Tuesday, June 21, 2005

Radium poisoning

If a person eats or drinks radium-tainted materials, about 80% of the radium will be excreted fairly quickly. The remaining 20% will be absorbed into the bloodstream and carried throughout the body.

Because radium is chemically similar to calcium, the body will mistakenly use it in various biochemical pathways that require calcium. In particular, the body will try to incorporate radium into bones and teeth.

Thus, smaller, chronic doses of radium have been strongly associated with cancer, particularly bone cancer. Larger doses can result in much more immediately serious disease.

An illness termed "radium jaw" (similar to "phossy jaw") was first seen in the mid-1920 amongst young women who worked in clock-dial painting factories that used radium to create the luminous paint. These women had the habit of licking their brushes to make the bristles form a point. As a result of their radium exposure, they were suffering horrible illness: their jawbones were disintegrating, their teeth were fracturing and falling out, and they were suffering from awful mouth and gum infections and ulcers.

A forensic pathologist named Harrison Martland discovered the radium paint was the culprit in 1925 after he tested the women and found that their breath carried radon gas (which is created from radium decay) and that their bodies were giving off faint gamma radiation.

Many of the radium-poisoned women died young, often from massive infections caused as a side effect of their immune systems having been severely impaired. Their bone marrow -- and thus their ability to make white blood cells -- had been destroyed by the radiation. These women didn't live nearly long enough to get cancer. Autopsies on the women showed that their spleens and livers were giving off alpha radiation and their bones were so radioactive that they would make an image if they were laid on photographic paper in a darkroom.

Most people are exposed to radium as a result of occupational exposures from working with radioactive materials, generally by breathing in tainted dust or vapors. Uranium miners are especially vulnerable. Radium itself is not thought to be readily absorbed through the skin, but the gamma radiation it gives off makes working near it unsafe.

If a person believes he or she has radium poisoning, they can get their urine tested for telltale radioactivity or have their breath tested for radon. Radium in the bloodstream may be removed with a chelating agent; however, once it's gotten into bones and teeth, the main medical treatment is supportive care for symptoms.

Small amounts of radium are found in coal, so people who live in coal-burning areas will be exposed to more of the radionuclide than people in other areas.

Also, radium occurs naturally in some soils and water. The EPA sets the acceptable limit for drinking water exposure at 5 picocuries per liter and 5 picocuries per gram of soil in the first 15 centimeters of soil and 15 picocuries per gram in deeper soil. Some naturally-tainted aquifers such as the Hickory Aquifer in West Texas may have many times the limit, though most water supplies have less than 1 picocurie per liter.

  • San Angelo Standard Times articles (various)
  • http://www.ccnr.org/
  • http://www.atsdr.cdc.gov/ToxProfiles/phs9022.html