Geologically, there are six forms of asbestos that is a naturally occurring mineral fiber found in rocks. Only three are used in commerce. Of the three, the one known as "blue asbestos" causes serious lung problems, including lung cancer, mesothelioma, and asbestosis. This asbestos material breaks into small fibers that can remain virtually suspended in the air indefinitely. These fibers are so small that they cannot be seen and will pass through the filters of normal vacuum cleaners. Once inhaled, asbestos fibers can become lodged in lung tissue and, after many years, cause cancer. Blue asbestos, however, has never been in general use in the U.S. Its only important application was in shipyards during World War II.

Soft white asbestos, called chrysotile, is by far the most important form of asbestos, since it is used in 95 percent of all asbestos applications. Soft white asbestos is naturally occurring in many localities. Lifetime exposures to chrysotile fibers in Quebec, where soft white asbestos is mined, show no statistically significant increase in lung disease among miners or their families.

The EPA's own data on the asbestos (chrysotile) content of water supplies in the U.S. show that millions of people are exposed to millions of fibers per liter of water. The measurement of asbestos in water from the Klamath River in California and Oregon showed 300 billion fibers per liter. These people drink, cook, garden, wash, and bathe with this water. Imagine the asbestos spread over the ground when the river floods. All this exposure is to the chrysotile type of asbestos. Even lifetime exposures to concentrations as high as two fibers per cubic centimeter of air have failed to show any significant hazard. The Chrysotile or soft white asbestos has fibers that can either dissolve or be removed from the lungs by normal physiological responses.

Even so, the U. S. Consumer Products Safety Commission has deemed that asbestos can be hazardous and has promulgated regulations concerning the control and disposal of materials containing asbestos. These regulations are still in effect. As a general rule, one should avoid disturbing it. The Puget Sound Air Pollution Control Agency has published a detailed how-to booklet for homeowners who wish to remove the textured from ceilings.

Materials that can be suspected of containing asbestos are textured ceilings, furnace duct insulation, hot water pipe wrappings, vinyl floor tiles, and siding shingles.

If there is a suspicion that a material contains asbestos, there are several recommendations. Removal should usually be the last choice among the alternatives. The less you disturb the asbestos product, the better.

Do not dust, sweep, or vacuum particles suspected of containing asbestos. Any dust should be removed by a wet-mopping procedure or by a specially designed vacuum cleaner used by certified asbestos workers.

If a ceiling with asbestos shows sings of fraying, or if one desires to refinish the surface, the ceiling can first be sprayed with a white tinted shellac. This will seal the fibers and prevent them from becoming airborne. The ceiling can then be refinished or painted.

It is always wise to seek additional advice if questions remain. "Environmental Overkill: Whatever Happened to Common Sense?" by Dixy Lee Ray is the source of portions of this article and has a very good bibliography of additional information.