What is Asbestos?
Asbestos Explained
What is asbestos? Asbestos is a group of naturally occurring fibrous minerals. It is mined and milled from rock and is thin and strong. Chrysotile (white asbestos), Amosite (brown asbestos), and Crocidolite (blue asbestos), are the most common types of asbestos used in manufacturing. Rarer forms are Tremolite, Anthophyllite, and Actinolite. When viewed under a microscope, Chrysotile fibers are pliable and cylindrical and are often arranged in bundles, whereas Amosite and Chrocidolite fibers appear to look like tiny needles. There have been more cases of Mesothelioma and cancer found in people working with Crocidolite than any other type of asbestos.
However, all forms of asbestos, except Chrysotile, are of the same mineralogical family called Amphiboles. Even though there appear to be fewer incidences of disease in workers who deal only with Chrysotile, all asbestos forms are believed to carry similar risks. Asbestos is a naturally occurring mineral and deposits of it can be found in most countries around the world. Most asbestos comes from the former Soviet Union, Canada, South Africa and Australia. Q. How is asbestos mined? Asbestos is mined from the ground usually by open-pit method. The raw material is very coarse and looks like old wood. The raw material is processed and refined into fluffy fibers. The fibers are added to a binding agent, like cement, to form an asbestos containing material.
Where is Asbestos Found?
In homes built prior to 1978, asbestos is most commonly found as thermal insulation on boilers and pipes. Unfortunately, it can also be found in many other household materials, which include: Attic insulation (blown in and sometimes vermiculite insulation) can contain asbestos. Textured ceilings. Asbestos was first used in the United States in the early 1900’s, to insulate steam engines but was not used extensively until the 40’s. After World War II, and for the next thirty years, schools and other public buildings were built using asbestos and asbestos-containing materials (ACM). Primarily, ACM was use as fireproofing, insulation, soundproofing and decoration.
Asbestos can enter the environment from natural mineral deposits which have been exposed to the weather, and fiber releases arising from the application, disturbance and removal of asbestos-containing materials (ACM). Asbestos may be found in products such as floor tiles, roof shingles, exterior siding, cement, automotive brakes, acoustical and structural insulation, etc. Asbestos fibers can be released into the air when ACM becomes damaged. If friable ACM (material that can be crumbled by hand pressure) is disturbed and becomes airborne, an inhalation hazard may result.
The Health Risk
It is important to note that not everyone who is exposed to asbestos develops an asbestos-related disease. Available information on the health effects related to asbestos exposure primarily comes from long-term studies of people exposed to large quantities of asbestos in the workplace. Asbestosis - Asbestos workers who breathe in asbestos fibers may develop a slow build-up of scar-like tissue in the lungs called asbestosis. This scarred tissue impairs the ability of the lungs and heart to adequately provide oxygen to the body. This is a serious disease and may take 20 to 30 years to develop after exposure.
Asbestosis can eventually lead to disability or death in people exposed to high amounts of asbestos. Lung Cancer and Mesothelioma - Asbestos workers also have an increased chance of developing two types of cancer: lung cancer and mesothelioma. Lung cancer starts within the respiratory tissues and mesothelial cancer grow from the thin membranes that surround the lung or the abdominal cavities. Both lung cancer and mesothelioma are usually fatal. These asbestos-related diseases do not appear immediately but may develop 20 to 50 years after exposure
How Asbestos Enters the Body
Asbestos fibers in non-friable ACM (i.e. floor tiles, sidings, laboratory desktops, etc.) are so tightly bound in the material that they are in, that they do not easily release fibers. However, if the material is abraded, sanded or sawed, the material can easily be rendered friable. You will need a respirator that is equipped with a High Efficiency Particulate (HEPA) filter. These filters are magenta colored. There are various factors that determine the type of respirator you need. To learn more about the respirators and what would best suit your situation, visit the Occupational Safety and Health Administration's website.
How do asbestos fibers enter the body? Inhalation - Breathing air which has asbestos fibers in it, is the primary route of damaging exposure. Some of the asbestos fibers reaching the lungs are eliminated in exhaled air and others are coughed up from the lungs with mucous. The fibers reaching the deepest air passages of the lungs can produce the greatest damage. Ingestion - The digestive system can be exposed to asbestos fibers from drinking water and mucous cleared from the lungs. A small number of fibers may penetrate the cells that line the digestive system, but only a few will reach the bloodstream. These fibers will be released in the urine Through the Skin - Asbestos fibers contacting the skin rarely pass through the skin into the body.