First of all, asbestos is used virtually everywhere in the U.S. Millions of tons of it are produced annually.  But the problem is not so much one of mass but one of smallness.  Tiny asbestos fibers can easily be inhaled into the lungs.  Once there they may be attacked by the body's defense mechanisms which snare and then transport these particles through the lymph channels to other body organs.  So it is that asbestos fibers have been found, not only in the lungs, but in the linings of the lungs, the liver, spleen, kidneys and pancreas.  And asbestos fibers last a long time in the human body, even, in some cases, a life-time.

Because they are essentially inert asbestos fibers can cause problems in the body many years later.  Latency periods for asbestos-related cancer or lung disease may range from 15 to 35 years.  That's why people are urged not to inhale asbestos fibers.  Smoking cigarettes greatly increases the risk of cancer in people who have been exposed to asbestos.

The asbestos problem:  since you can't eliminate asbestos from the body, the best medicine here--is avoidance.  For a copy of this script access our web site, speakingofhealth.com.  Speaking of Health, I'm Dr. Steven Andrew Davis, for CBS News.