This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on February 28, 2022.
Asbestos is a combination of natural minerals that come together in the form of fibers. It occurs naturally in rocks and soil in some places, but it was also added to materials during manufacturing due to its strength and heat-resistance.
In the past century, though, asbestos has been linked to health problems—including cancer risk—and its use in manufacturing has been limited or banned in many countries, including the United States.
Even though it’s less likely to be used in factories now, asbestos is sometimes still found in the following, among others:
Another place asbestos is found is in disaster areas where buildings have been damaged. One example is the World Trade Center debris after the Sept. 11, 2001, attack.
At any given time, asbestos may be in the air or water at very low levels that don’t typically cause health problems.
If left alone, materials containing asbestos aren’t damaging. But if disturbed, such as during construction—whether tearing down buildings or overturning soil and rock with naturally occurring asbestos inside—asbestos fibers may be inhaled or swallowed, leading to health problems, especially in the lungs.
Asbestos may also be released when older materials corrode or break down.
Asbestos doesn’t create problems immediately upon exposure. It may take years of exposure before asbestos begins to have a noticeable effect on health.
But certain groups of people may have higher levels of long-term exposure to asbestos than others, such as those who currently work—or have worked—in:
Family members may be exposed to asbestos too, as workers bring fibers home on their clothing or other belongings.
There are two main health conditions associated with asbestos:
Several organizations, including the World Health Organization (WHO), the National Toxicology Program (NTP) and the U.S. Environmental Protection Agency (EPA), have all named asbestos as a known carcinogen, meaning that it’s a substance that has the ability to cause cancer.
Mesothelioma: The clearest link is between asbestos and mesothelioma, which affects the protective tissue that lines the lungs and abdomen, called the mesothelium. About 75 percent to 80 percent of mesotheliomas start in the area of the lungs, according to the American Society of Clinical Oncology (ASCO). Rarely, mesothelioma may also begin in the lining of the heart or the lining of the testicles. The majority of people diagnosed with mesothelioma—70 percent to 80 percent—have known exposure to asbestos, according to ASCO.
Lung cancer: Asbestos exposure has also been linked to lung cancer. However, those who develop lung cancer connected to asbestos exposure typically aren’t diagnosed until 15 years after they were first exposed or later. The risk of developing lung cancer connected to asbestos exposure is much higher in people who smoke.
Ovarian cancer: When it comes to ovarian cancer, several studies have shown a connection to asbestos exposure, but some scientists think more research is needed to determine whether asbestos clearly causes this type of cancer. Despite this call for more evidence, the WHO’s International Agency for Research on Cancer does cite asbestos as a cause of ovarian cancer.
Laryngeal cancer: For laryngeal cancer, some studies have shown a connection between asbestos and cancer of the larynx (voice box), but others have not. Ultimately, the evidence is mixed for a link between asbestos and laryngeal cancer.
Other cancers: For cancers such as kidney cancer, stomach cancer, pharyngeal cancer and colorectal cancer, a few studies have suggested a connection with asbestos, but more research is needed before a clear connection can be made.
Now that you know more about the connection between asbestos exposure and your health, you can take steps to reduce your risk of asbestos-related issues. Keep in mind that risk for asbestos-related problems is most associated with high levels of exposure or long-term exposure over many years. You may: