Asbestos is a naturally occurring silicate mineral with long, thin fibrous crystals. The word asbestos (ἄσβεστος) is a borrowed Greek adjective meaning inextinguishable. The Greeks termed asbestos the miracle mineral because of its soft and pliant properties, as well as its ability to withstand heat. This article describes this miracle mineral and why asbestos in your home can be toxic to you and your family.
What is Asbestos?
- Asbestos may be 1 of 6 minerals.
- These minerals will not crush into dust like other rocks, but separate into fibers.
- Asbestos occurs as veins in rocks.
- Asbestos is mind from the ground, like coal. It is no longer mind in the United States, but is mostly mined in Canada, South Africa, and Russia.
- After being mined, asbestos is then crushed milled and then processed and mixed into other materials.
- Asbestos is no longer permitted to be used in the making of building materials in the U.S., but other countries continue to use it.
- Chrysotile (cry-so-tile) – “white asbestos” – Is the most common type of asbestos used in building materials (95%) and is heat resistant and was used in fireproofing, insulation. Water can be sprayed on Chrysotile to prevent it from becoming airborne.
- Amosite (am-o-site) – “Brown asbestos” – was used often in pipe and boiler insulation. Plain water does not work well to keep the fibers out of the air.
- Crocidolite (cro-cid-o-lite) –Blue asbestos” was used often in grout.
Asbestos was used in building material more commonly after World War II until its effect on health became known. While many uses of asbestos are now banned, many are not. Even if your home was built after 1980 it may contain asbestos. You might be jumping out of your chair right now ready to add a flaming comment to this article below, but first you should download and read this article from the EPA I entitled Most Asbestos Is Not Banned.
Asbestos helped building materials to last longer. Because of its physical properties, asbestos was used in over 3,500 different products.
Application Categories –
- Surfacing – This is where ACBM is sprayed or troweled on.
- Thermal System Insulation (TSI) – Material used for insulation.
- Other Miscellaneous Materials – Brake shoes, clothing/textiles
- Fireproofing – Because of its resistance to heat asbestos was used in sprayed on fireproofing materials that was sprayed on metal decking and structural members.
- Insulating – Used in insulation that covered pipes, boilers, etc.
- Noise Reduction- Used in acoustical ceiling tiles.
- Strengthening additive – Used in floor tiles, cement, textiles.
- Friction reduction – Used in transmission clutches and brake shoes.
- Paint – Sprayed on textured paint.
One of the most important factors of asbestos is that its fibers are extremely small and can get past the human body’s defense systems and into the lungs. The fibers can not be seen by the naked eye. If looked at under a microscope, each fiber is actually a bundle made up of tiny pieces called “fibrils”. These fibers, if they become airborne, are easily inhaled. They stay suspended in air for a long time, which makes it difficult to clean and remove the asbestos in a area.
ACBM is categorized as Friable and Non-Friable. Friable means that the ACBM can easily be crushed or reduced to a powder with light hand pressure and therefore, more easily become airborne. Friable ACBM has more chance to become harmful than non-friable ACBM. It is also important to note that Non-friable materials can become friable if they are damaged. Since the tiny fibers can get past the defense systems, they can get stuck in the lower portions of the lungs and remain there which can lead to several asbestos-related diseases. Hundreds of thousand of fibers can be in the lungs before any health effects are noticed or can be detected by a physician. We do know that asbestos related diseases don’t heal themselves. This is why it is important to have medical surveillance programs.
How does asbestos enter the body?
Asbestos enters the body through our Respiratory System. The asbestos can enter through the nose or mouth, travel by the Larynx, down the trachea to the bronchi and enter the alveoli which are the air sac at the bottom of the lungs. Most asbestos-related diseases result from the inhalation of airborne asbestos fibers. The lungs are lined with a membrane tissue called the mesothelium. When we breathe, the chest and lungs expand and contract. Asbestos related diseases affects the breathing ability and makes the expanding and contraction difficult.
The body’s defenses against asbestos
Our bodies have several defense mechanisms to help filter the air that we breathe. The mucous that we generate helps trap dust and other foreign particles. Our airways are lined with hair like structures called Cilia. The cilia continually beat upwards to move the trapped particles up and away from the lungs so we can cough or spit them out. This functions is called the mucociliary escalator.
There is an important relationship between smoking and asbestos. Smoking paralyzes the cilia (puts them to sleep). This lessens the defense mechanism the body has against asbestos.
Macrophages are specialized white blood cells in the lungs that actually eat microorganisms and foreign particles, but since asbestos is a mineral, it will not work against it. Instead, scar tissue forms when the macrophage tries to destroy the asbestos. The scarring leads to the development of asbestosis.
Diseases caused from asbestos exposure
- Asbestosis - Asbestosis is the scaring of the lungs that occur in the air sacs. An x-ray of the lower lungs would look like cobwebs. This scaring increases the risk of getting lung cancer. The scaring prevents the lungs from expanding and contracting normally and therefore causes shortness of breathe and other symptoms such as tiring easily, lose of weight, and coughing.
- Latency Period - The latency period is the time between the asbestos exposure and the appearance of asbestos related disease. Health effects from exposure to asbestos are not obvious immediately. Asbestosis can take up to 15 years to develop.
- Dose-Response Relationship - The greater exposure (dose) you have, the more likely you are to develop disease (response). Asbestosis is usually detected in workers who have had a high exposures to asbestos, and have worked with it over a long period of time. There is a clear dose response relationship with asbestosis.
- Lung Cancer - Asbestos exposure is only one of many causes of lung cancer, but it is the most common and serious disease associated with asbestos exposure.
- Mesothelioma - Mesothelioma is a rare type of cancer, which spread rapidly and is always fatal. The exact cause of this cancer is unknown. It affects the chest cavity lining (pleural) or the lining of the abdomen thought to be caused by swallowing asbestos either from coughing or eating in an asbestos work area. This disease has a latency period of 30 to 40 years. There is NOT a clear dose-response relationship with mesothelioma. There are some cases where asbestos exposure was limited , like Steve McQueen who was an actor and drove race cars who died from mesothelioma.
Other Diseases
- Gastro-intestinal tract cancers (can be treated if detected early)
- Pleural plaques
- Pleural effusion
- Pleural thickening
- Macrophage
EPA “Five Facts”
- Asbestos is hazardous, but the risk depends on the exposure to airborne asbestos fibers.
- The average airborne asbestos level in most buildings is low, and therefore, the risk to most building occupants appears to be low.
- Removal is not always the best course of action.
- EPA requires removal only if there could be significant public exposure during demolition or renovation
- The EPA recommends a proactive, in-place management program for all ACBM.
