What is asbestos?
Asbestos is the name given to a group of natural mineral fibers that are known for their strength and for their fire and chemical–resistant properties. Because of these qualities, asbestos has been used as a strengthening agent in cement and plastics, as well as a material for insulation, fireproofing, and sound absorption in numerous manufacturing and building and construction industries.
Asbestos fiber colors come in blue, brown, gray, green, and white. In the United States, the white-colored asbestos fibers, called chrysotile, have been the most commonly used. Crocidolite, amosite, or anthophyllite are the names of three other types of asbestos materials used for commercial purposes.
What types of products contain asbestos?
More than 5,000 products contain or have contained asbestos. Some of these products include:
- Pipe and furnace insulation materials
- Asbestos and cement shingles, sliding, and roofing materials
- Casings for electrical wires
- Resilient floor tiles, the backing on vinyl sheet flooring, and floor tile adhesives
- Soundproofing or decorative material
- Patching and joint compound
- Fireproof gloves, stove-top pads, table pads, fire-resistant fabrics including blankets and curtains
- Automobile brake pads and linings, clutch facings, and gaskets
- Artificial ashes and embers used in gas-fired fireplaces
- Some plastics; paints, coatings, and adhesives
- Some vermiculite-containing attic insulation and consumer garden products
What are the health effects of asbestos?
When asbestos-containing materials are disturbed or during improper removal, the asbestos fiber can easily break down into tiny particles too small to be seen and become airborne. Once airborne, the particles can be inhaled and can remain and accumulate in the lungs.
Exposure to asbestos may increase the risk of developing any of the following diseases and conditions:
- Lung cancer
- Asbestosis, which results in permanent lung damage (a scarring of the lung tissue)
- Mesothelioma, a relatively rare cancer of the chest and abdominal linings
- Other cancers, including those of the larynx, oropharynx, gastrointestinal tract, and kidney
- Pleural plaques that result in scarring of the lining of the lung
- Small pleural effusions (collections of fluid around the lung)
Due to these health risks, in the late 1970s, the US Consumer Product Safety Commission banned the use of asbestos in several products. In 1989, the US Environmental Protection Agency banned all new uses of asbestos. However, many products and particularly buildings that were built before the late 1970s contain asbestos.
Who is most at risk of exposure to asbestos?
Most people who have asbestos-related illnesses have had regular exposure to it, typically through jobs where they’ve worked directly with the material. Occupations in which workers have received such exposure include the ship building trades, railway construction, asbestos mining and milling, construction and building trades (specifically insulation workers, plumbers, pipefitters, electricians, carpenters, boilermakers, welders and cutters), chemical manufacturing, flooring manufacturing, plastic and rubber manufacturing, the auto industry (specifically brake repair), firefighters, fabric mills workers, and building demolition workers.
It is well known that the longer a person has been exposed to asbestos as well as the greater the intensity of the exposure, the greater the chance of developing an asbestos-related disease. However, asbestos-related diseases also have been diagnosed in individuals with only brief exposures. People who develop asbestos-related diseases usually show no signs of illness for a long time – for as long as 10 to 40 years – after their first exposure.
How great is the risk?
Not all individuals who have been exposed to asbestos develop diseases related to their exposure. The risk varies with the extent of exposure, length of exposure, and type of industry in which the exposure took place. For example, industries in which the asbestos is bonded into finished products such as walls and tiles pose little health risk. Industries in which asbestos is released into the air, such as from sawing or drilling activities, pose a greater risk.
Does smoking increase the risk?
Smoking markedly increases the risk of lung cancer in individuals with asbestos exposure. Asbestos exposure in the absence of a smoking history is associated with a 6-fold increase in risk for developing lung cancer. Cigarette smoking without a history of asbestos exposure is associated with an 11-fold increase in risk. The relative risk for cigarette smokers with a history of asbestos, however, is much higher than either exposure alone, approaching a 60-fold increase in risk.
Although smoking does not appear to increase the risk of mesothelioma, individuals exposed to asbestos on the job or at any time during their life should not smoke.
Do family members of asbestos-exposed individuals face any increased health risks?
This type of “second-hand” exposure is called paraoccupational exposure. It occurs when asbestos particles are brought into the home on the shoes, clothing, skin, and hair of the exposed individual. There is some evidence that family members of individuals heavily exposed to asbestos face an increased risk of developing mesothelioma.
However, to decrease these so-called "second-hand" exposures, most industries that use asbestos-containing products have the workers change clothing upon arrival and departure from work. Showers are also available for workers to cleanse any remaining particles from their hair and skin. The contaminated clothing is handled and laundered by personnel who wear protective clothing and receive training to prevent exposure.
What are the symptoms of asbestos-related diseases?
As noted earlier, it can take many years to several decades after exposure for an asbestos-related disease to develop. If any of the following symptoms do develop, make an appointment to see your doctor as soon as possible:
- Shortness of breath
- Development of a cough or a change in cough patterns
- Blood in the sputum coughed up from the lungs
- Pain in the chest or abdomen
- Difficulty in swallowing or prolonged hoarseness
- Significant weight loss
What kinds of tests might my doctor order?
First, your doctor will ask you about any symptoms you might be experiencing as well as ask questions about your occupation and job-related exposure to asbestos. Next, your doctor will conduct a thorough physical exam, including lung function tests and a chest X-ray to look for any changes in the lung function and structure resulting from asbestos exposure. The presence of asbestos can also be measured in urine, feces, mucus, or material rinsed out of the lungs. Depending on the findings of the initial evaluation, further testing to take a closer look at the lungs may be recommended. These tests may include CT scans (a form of X-ray), bronchoscopy (passing a small tube down the windpipe and into the airways of the lungs), and possibly a lung biopsy (a small tissue sample).
If I suspect I have asbestos materials in my home, what should I do?
Asbestos fibers are not harmful unless released into the air. Fortunately, the asbestos used in building materials and other products on the market today is encased in or bonded into the products, which helps prevent the fibers from being released into the air. Therefore little to no risk is posed from the installation of asbestos-based products and materials. The only general precaution would be to avoid sanding, tearing, or other actions that might damage or crumble the material and release the fibers into the air.
It’s usually best to leave asbestos materials that are already in your home AND that are in good condition alone. Do not touch or otherwise disturb the material. Inspect it from time to time to look for signs of damage or deterioration. There is no risk involved as long as the material is neither crumbly nor damaged.
If you do see signs of damage or deterioration, have the material sampled and analyzed by a qualified professional. If the sampled material does turn out to be asbestos AND it is more than slightly damaged, the asbestos material will need to be either removed or repaired. There are two methods of repair, but the goal of each is the same – to prevent the airborne release of asbestos fibers. One method of repair simply involves covering the material with a protective wrap. A second method, called sealing, coats the fibers with a substance so that the fibers bind together and have less of a chance of being released into the air. Repair is usually less expensive than removal procedures.
If I do wish to repair or remove asbestos-containing products in my home, can I do the work myself?
Regardless of whether the job is to test, repair, or remove asbestos, the Environmental Protection Agency recommends that an asbestos professional be hired to do the work. Improper handling of asbestos material can create more of a hazard than leaving the material undisturbed.
What should I look for when hiring an asbestos removal/repair contractor?
Here are some useful suggestions:
- Ask to see the contractor’s certificate of completion of a federal or state-approved training program.
- Ask for references of clients for whom the contractor has done previous work. Call to determine if the clients were satisfied with the work.
- To guard against conflict of interest issues, select a different contractor from the one who tested for asbestos.
- Make sure the work area is sealed off from the rest of the house. Plastic sheeting and duct tape work well to seal off areas.
- Make sure the air conditioning and heating system is turned off.
- Insist that the contractor applies a wetting agent to the asbestos material to minimize the release of fibers into the air.
- Clean up should be handled with wet mops, rags, and sponges. Do not allow the use of ordinary vacuum cleaners. Asbestos fibers can pass through the filter of ordinary vacuum cleaners and become airborne. HEPA (high efficiency particulate air) vacuum cleaners, however, can be used.
- Make sure that all asbestos materials, disposable equipment, and clothing are placed in sealed and marked containers and are disposed of properly.
I work in an industry that uses asbestos products. How can I ensure that my employer has taken all the necessary steps to protect my health?
Employees should discuss any concerns with other employees, their health and safety representative, and their employer. Employers are required to follow regulations related to asbestos exposure on the job. The Federal agencies that are responsible for health and safety issues in the workplace are the Occupational Safety and Health Administration (OSHA), the Mine Safety and Health Administration (MSHA), and the National Institute of Occupational Safety and Health (NIOSH).
Contact any of these agencies for additional information and assistance.
Occupational Safety and Health Administration (OSHA)
Mine Safety and Health Administration (MSHA)
National Institute of Occupational Safety and Health (NIOSH)
Other organizations that provide information about asbestos exposure include:
Agency for Toxic Substances and Disease Registry (ATSDR)
US Environmental Protection Agency (EPA)
US Consumer Product Safety Commission (CPSC)
© Copyright 1995-2013 The Cleveland Clinic Foundation. All rights reserved.
This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 10/22/2013...#11394