“Asbestos” is the name given to a group of minerals that occur naturally as bundles of fibers which can be separated into thin threads. These fibers are not affected by heat or chemicals and do not conduct electricity. For these reasons, asbestos has been widely used in many industries. Four types of asbestos have been used commercially:

-Chrysotile, or white asbestos;
-Crocidolite, or blue asbestos;
-Amosite, which usually has brown fibers; and
-Anthophyllite, which usually has gray fibers.

Chrysotile asbestos, with its curly fibers, is in the serpentine family of minerals. The other types of asbestos, which all have rod-like fibers, are known as amphiboles.
Asbestos fiber masses tend to break easily into a dust composed of tiny particles that can float in the air and stick to clothes. The fibers may be easily inhaled or swallowed and can cause serious health problems.

How is asbestos used?
Asbestos has been used in many industries,for example, the building and construction industry,for strengthening cement and plastics as well as for insulation, fireproofing, and sound absorption. The shipbuilding industry has used asbestos to insulate boilers, steampipes, and hot water pipes. The automotive industry uses asbestos in vehicle brakeshoes and clutch pads. More than 5,000 products contain or have contained asbestos. Some of them are listed below:

-Asbestos cement sheet and pipe products used for water supply and sewage piping, roofing and siding, casings for electrical wires, fire protection material, electrical switchboards and components, and residential and industrial building materials;

-Friction products, such as clutch facings, brake linings for automobiles, gaskets, and industrial friction materials;

-Products containing asbestos paper, such as table pads and heat-protective mats, heat and electrical wire insulation, industrial filters for beverages, and underlying material for sheet flooring;

-Asbestos textile products, such as packing components, roofing materials, and heat- and fire-resistant fabrics (including blankets and curtains); and

-Other products, including ceiling and floor tile; gaskets and packings; paints, coatings, and adhesives; caulking and patching tape; artificial ashes and embers for use in gas-fired fireplaces; plastics; vermiculite-containing consumer garden products; and some talc-containing crayons.

What are the health hazards of exposure to asbestos?
Exposure to asbestos may increase the risk of several serious diseases:

-Asbestosis-a chronic lung ailment that can produce shortness of breath, coughing, and permanent lung damage;
-Lung cancer;
-Mesothelioma-a relatively rare cancer of the thin membranes that line the chest and abdomen; and
-Other cancers, such as those of the larynx, oropharynx, gastrointestinal tract, and kidney.

Who is at risk?
Nearly everyone is exposed to asbestos at some time during their life. However, most people do not become ill from their exposure. People who become ill from asbestos are usually those who are exposed to it on a regular basis, most often in a job where they work directly with the material or through substantial environmental contact.

Although it is known that the risk to workers increases with heavier exposure and longer exposure time, investigators have found asbestos-related diseases in individuals with only brief exposures. Generally, those who develop asbestos-related diseases show no signs of illness for a long time after their first exposure. It can take from 10 to 40 years for symptoms of an asbestos-related condition to appear.

There is some evidence that family members of workers heavily exposed to asbestos face an increased risk of developing mesothelioma. This risk is thought to result from exposure to asbestos fibers brought into the home on the shoes, clothing, skin, and hair of workers. This type of exposure is called paraoccupational exposure. To decrease these exposures, people exposed to asbestos at work are required to shower and change their clothing before leaving the workplace.

How does smoking affect risk?
Many studies have shown that the combination of smoking and asbestos exposure is particularly hazardous. Smokers who are also exposed to asbestos have a greatly increased risk of lung cancer. However, smoking combined with asbestos exposure does not appear to increase the risk of mesothelioma.

There is evidence that quitting smoking will reduce the risk of lung cancer among asbestos-exposed workers. People who were exposed to asbestos on the job at any time during their life or who suspect they may have been exposed should not smoke. If they smoke, they should stop.

Who needs to be examined?
As noted earlier, the symptoms of asbestos-related diseases may not become apparent for many decades after exposure. If any of the following symptoms develop, a physical examination should be scheduled without delay:

-Shortness of breath;
-A cough or a change in cough pattern;
-Blood in the sputum (fluid) coughed up from the lungs;
-Pain in the chest or abdomen;
-Difficulty in swallowing or prolonged hoarseness; and/or
-Significant weight loss.

How can workers protect themselves?
Employers are required to follow regulations dealing with asbestos exposure on the job.
Workers who are concerned about asbestos exposure in the workplace should discuss the situation with other employees, their employee health and safety representative, and their employers.