Asbestos exposure has serious long-term health consequences. This though does not imply that you must be exposed for long periods of time to develop an asbestos disease. There have been cases of children developing asbestos related maladies simply from asbestos exposure of their fathers work clothes who worked in asbestos related industries. The nature of asbestos fibers, allow them to become imbeded in the lung tissues.
Low levels of asbestos are in the air we breathe and some of the water we drink, including water from natural sources. Studies have shown that members of the general population have tens of thousands to hundreds of thousands of asbestos fibers in each gram of dry lung tissue, which translates into millions of fibers and tens of thousands of asbestos bodies in every person's lungs.
The EPA has proposed a concentration limit of 7 million fibers per liter of drinking water for long fibers (lengths greater than or equal to 5 µm). OSHA (Occupational Safety and Health Administration) has set limits of 100,000 fibers with lengths greater than or equal to 5 µm per cubic meter of workplace air for 8-hour shifts and 40-hour work weeks.
Most respirable asbestos fibers are invisible to the unaided human eye because their size is about 3.0-20.0 in length and can be as thin as 0.01 µm. Human hair ranges in size from 17 to 181 µm in width. Fibers ultimately form because when these minerals originally cooled and crystallized, they formed by the polymeric molecules lining up parallel with each other and forming oriented crystal lattices. These crystals thus have three cleavage planes, just as other minerals and gemstones have. But in their case, there are two cleavage planes that are much weaker than the third direction. When sufficient force is applied, they tend to break along their weakest directions, resulting in a linear fragmentation pattern and hence a fibrous form. This fracture process can keep occurring and one larger asbestos fiber can ultimately become the source of hundreds of much thinner and smaller fibers.
As asbestos fibers get smaller and lighter, they more easily become airborne and human respiratory exposures can result. Fibers will eventually settle but may be re-suspended by air currents or other movement.
Friability of an asbestos containing product means that it is so soft and weak in structure that it can be broken with simple finger crushing pressure. Friable materials are of the most initial concern due to their ease of damage. The forces or conditions of usage that come into intimate contact with most non-friable asbestos containing materials are substantially higher than finger pressure. Non-friable asbestos products can release substantial quantities of asbestos fibers into their environments as well. "asbestos." Wikipedia. Wikipedia, 2007. Answers.com 29 Apr. 2007. http://www.answers.com/topic/asbestos
No particular asbestos symptom is evident for many years, but the eventuality of asbestos exposure is lung cancer, mesothelioma a cancer of the linings surrounding the lungs, asbetosis and some gastro-intestinal cancer.
So if you have asbestos materials in your home please handle with care. If in doubt hire a professional to check it out or do a test yourself.
