ToxFAQs for Asbestos
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This fact sheet answers the most frequently asked health questions about asbestos. For more information, you may call the ATSDR Information Center at 1-888-422-8737. This fact sheet is one in a series of summaries about hazardous substances and their health effects. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present.
Exposure to asbestos
usually occurs by breathing contaminated air in workplaces
that make or use asbestos. Asbestos is also found in the
air of buildings containing asbestos that are being torn
down or renovated. Asbestos exposure can cause serious
lung problems and cancer. This substance has been found
in at least 83 of the 1,585 National Priorities List sites
identified by the Environmental Protection Agency (EPA).
What is asbestos?
Asbestos is the name given to a group
of six different fibrous minerals (amosite, chrysotile, crocidolite,
and the fibrous varieties of tremolite, actinolite, and anthophyllite)
that occur naturally in the environment. Asbestos minerals
have separable long fibers that are strong and flexible enough
to be spun and woven and are heat resistant. Because of these
characteristics, asbestos has been used for a wide range of
manufactured goods, mostly in building materials (roofing
shingles, ceiling and floor tiles, paper products, and asbestos
cement products), friction products (automobile clutch, brake,
and transmission parts), heat-resistant fabrics, packaging,
gaskets, and coatings. Some vermiculite or talc products may
What happens to asbestos when it enters the
Asbestos fibers can enter the air or
water from the breakdown of natural deposits and manufactured
asbestos products. Asbestos fibers do not evaporate into air
or dissolve in water. Small diameter fibers and particles
may remain suspended in the air for a long time and be carried
long distances by wind or water before settling down. Larger
diameter fibers and particles tend to settle more quickly.
Asbestos fibers are not able to move
through soil. Asbestos fibers are generally not broken down
to other compounds and will remain virtually unchanged over
How might I be exposed to asbestos?
We are all exposed to low levels of asbestos
in the air we breathe. These
levels range from 0.00001 to 0.0001 fibers per milliliter
of air and generally are highest in cities and industrial
People working in industries that make
or use asbestos products or who are involved in asbestos mining
may be exposed to high levels of asbestos. People living near
these industries may also be exposed to high levels of asbestos
Asbestos fibers may be released into
the air by the disturbance of asbestos-containing material
during product use, demolition work, building or home maintenance,
repair, and remodeling. In general, exposure may occur only
when the asbestos-containing material is disturbed in some
way to release particles and fibers into the air.
Drinking water may contain asbestos from
natural sources or from asbestos-containing cement pipes.
How can asbestos affect my health?
Asbestos mainly affects the lungs and
the membrane that surrounds the lungs. Breathing high levels
of asbestos fibers for a long time may result in scar-like
tissue in the lungs and in the pleural membrane (lining) that
surrounds the lung. This disease is called asbestosis and
is usually found in workers exposed to asbestos, but not in
the general public. People with asbestosis have difficulty
breathing, often a cough, and in severe cases heart enlargement.
Asbestosis is a serious disease and can eventually lead to
disability and death.
Breathing lower levels of asbestos may
result in changes called plaques in the pleural membranes.
Pleural plaques can occur in workers and sometimes in people
living in areas with high environmental levels of asbestos.
Effects on breathing from pleural plaques alone are not usually
serious, but higher exposure can lead to a thickening of the
pleural membrane that may restrict breathing.
How likely is asbestos to cause cancer?
The Department of Health and Human Services
(DHHS), the World Health Organization (WHO), and the EPA have
determined that asbestos is a human carcinogen.
It is known that breathing asbestos can
increase the risk of cancer in people. There are two types
of cancer caused by exposure to asbestos: lung cancer and
mesothelioma. Mesothelioma is a cancer of the thin lining
surrounding the lung (pleural membrane) or abdominal cavity
(the peritoneum). Cancer from asbestos does not develop immediately,
but shows up after a number of years. Studies of workers also
suggest that breathing asbestos can increase chances of getting
cancer in other parts of the body (stomach, intestines, esophagus,
pancreas, and kidneys), but this is less certain. Early identification
and treatment of any cancer can increase an individual's quality
of life and survival.
Cigarette smoke and asbestos together
significantly increase your chances of getting lung cancer.
Therefore, if you have been exposed to asbestos you should
stop smoking. This may be the most important action that you
can take to improve your health and decrease your risk of
How can asbestos affect children?
We do not know if exposure to asbestos
will result in birth defects or other developmental effects
in people. Birth defects have not been observed in animals
exposed to asbestos.
It is likely that health effects seen
in children exposed to high levels of asbestos will be similar
to the effects seen in adults.
How can families reduce the risk of exposure to
Materials containing asbestos that are
not disturbed or deteriorated do not, in general, pose a health
risk and can be left alone. If you suspect that you may be
exposed to asbestos in your home, contact your state or local
health department or the regional offices of EPA to find out
how to test your home and how to locate a company that is
trained to remove or contain the fibers.
Is there a medical test to show whether I've been
exposed to asbestos?
Low levels of asbestos fibers can be measured in urine, feces, mucus, or lung washings of the general public. Higher than average levels of asbestos fibers in tissue can confirm exposure but not determine whether you will experience any health effects.
A thorough history, physical exam, and diagnostic tests are needed to evaluate asbestos-related disease. Chest x-rays are the best screening tool to identify lung changes resulting from asbestos exposure. Lung function tests and CAT scans also assist in the diagnosis of asbestos-related disease.
Has the federal government made recommendations to protect human health?
In 1989, EPA banned all new uses of asbestos; uses established before this date are still allowed. EPA established regulations that require school systems to inspect for damaged asbestos and to eliminate or reduce the exposure by removing the asbestos or by covering it up. EPA regulates the release of asbestos from factories and during building demolition or renovation to prevent asbestos from getting into the environment.
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).
The 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.
Agency for Toxic Substances and Disease Registry (ATSDR). 2001. Toxicological Profile for Asbestos. Update. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.
Where can I get more information?
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact:
Agency for Toxic Substances and Disease Registry
Office of Innovation and Analytics, Toxicology Section
4770 Buford Highway
Chamblee, GA 30341-3717
Phone: 1-800-CDC-INFO 888-232-6348 (TTY)
Email: Contact CDC-INFO
ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.