Table of ContentsView AllTable of ContentsHow They Cause CancerExposure to Carcinogens and Increased Cancer RiskTypesHow to Reduce Exposure to Carcinogens
Table of ContentsView All
View All
Table of Contents
How They Cause Cancer
Exposure to Carcinogens and Increased Cancer Risk
Types
How to Reduce Exposure to Carcinogens
Carcinogens are substances or agents that can cause cancer. These can occur in nature, such as with ultraviolet radiation and someviruses, or be manmade, as seen in car fumes andcigarette smoke.
While it’s impossible to eliminate all carcinogen exposure, you can take steps to reduce what you come in contact with.
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How Carcinogens Cause Cancer
A carcinogen can directly damage DNA and cause changes calledmutations. Other times a carcinogen may cause cells to divide more rapidly than normal, which increases the chances of DNA becoming altered and raises the risk of developing cancer.
Carcinogens have thepotentialto cause cancer, but being exposed to these substances does not definitely mean you will get cancer.
Your risk of cancer increases based on several factors:
How Long Before Carcinogens Cause Cancer?Thelatency period, the time between exposure to a carcinogen and clinical onset of cancer, depends on the type of carcinogen and your risk factors, but often it takes a long time, sometimes decades, before cancer is detected.
How Long Before Carcinogens Cause Cancer?
Thelatency period, the time between exposure to a carcinogen and clinical onset of cancer, depends on the type of carcinogen and your risk factors, but often it takes a long time, sometimes decades, before cancer is detected.
Even when damage to DNA occurs, your body can produce proteins that either repair damaged DNA or eliminate damaged cells before a normal cell is transformed into acancer cell.Tumor suppressor genesalso slow down cell division and do repairs.
Types of Carcinogens
Carcinogens exist in a range of indoor or outdoor environments. They include chemicals, viruses, medications, and pollutants.
Some carcinogens are linked to specific types of cancer.
How Carcinogens Are ClassifiedThe International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO) has evaluated more than 1,000 possible carcinogens. These are divided into the following groups:Group 1:Carcinogenic to humans(only about 120 substances are confirmed to be in this group)Group 2A:Probably carcinogenic to humansGroup 2B:Possibly carcinogenic to humansGroup 3:Not classifiable as to its carcinogenicity in humans
How Carcinogens Are Classified
The International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO) has evaluated more than 1,000 possible carcinogens. These are divided into the following groups:Group 1:Carcinogenic to humans(only about 120 substances are confirmed to be in this group)Group 2A:Probably carcinogenic to humansGroup 2B:Possibly carcinogenic to humansGroup 3:Not classifiable as to its carcinogenicity in humans
The International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO) has evaluated more than 1,000 possible carcinogens. These are divided into the following groups:
Home and Workplace Chemicals
Many chemicals used in building materials or products in the home or workplace may be carcinogenic. Two common ones are formaldehyde andasbestos.
Environmental Radiation
Another common form of environmental radiation isradon, which is emitted from the normal decay of uranium in the soil and then gets trapped in homes. Radon is the second leading cause of lung cancer after smoking.
You can have your hometested for radonand install a radon mitigation system if levels are high.
Medical Radiation
Radiation exposure that occurs during certain diagnostic tests, such ascomputed tomography (CT scan), andradiation therapyused to treat cancer is carcinogenic.
For example, women who receive radiation therapy after amastectomy, a procedure to remove a breast due to breast cancer, are at an increased risk of developing lung cancer due to the radiation that is delivered to the chest area.
However, the risks of not getting such imaging or treatment when needed are often considered greater than those associated with medical radiation.
Viruses
There are several viruses linked to cancer. These affect healthy cells’ genetic makeup and can make it more likely that they will turn into cancer.
Viruses that can lead to cancer include:
There areHPV vaccinesandhepatitis B vaccinesthat can reduce your risk of getting these viruses and the cancers linked to them. They are only effective if vaccination occurs prior to being exposed to the virus.
Medications
Somechemotherapyand hormonal therapy drugs can raise the risk of cancer.
For example, chemotherapy drugs such as Ellence (epirubicin), used for early-stagebreast cancer, can sometimes lead to leukemia when administered in high doses.
Oral contraceptives may increase the risk of breast cancer or cervical cancer, but they maylowerthe risk ofendometrial,ovarian, andcolorectal cancers.
Pollution
Both outdoor and indoor air may contain pollutants that are carcinogenic.
Common outdoor air pollutants from industrial or power plants, engine exhaust, and fire smoke are strongly linked with lung cancer.
Indoor air pollutants can come from a variety of sources such as building materials, fire retardants, paint fumes, cleaning products, and dust. Indoor air pollutants can also lead to the development of lung cancer.
Lifestyle Factors
There are a variety of lifestyle factors that can contribute to mutations that result in cancer.
Lifestyle-related carcinogens include:
There is also some evidence that cooking meat at high temperatures—grilling or pan frying it, for example—may create carcinogenic compounds that can then be consumed.
Cooking meats for longer times at lower temperatures and removing any charred portions before eating may help reduce your risk.
Because not every substance that may be a carcinogen has been tested, it’s important to practice discretion with any potential carcinogens you may be exposed to.
These tips can help you get a sense of what those might be and what to do if you encounter them:
Summary
Exposure can come from home chemicals, environmental or medical radiation, medications, viruses, polluted air, and lifestyle choices. They are a part of daily life, so you really can’t avoid them entirely. But you can take steps to protect yourself, such as wearing gloves, reading labels, and not smoking.
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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Cancer Society.Carcinogens and the cancer connection.National Cancer Institute.Environmental carcinogens and cancer risk.American Cancer Society.Known and Probable Human Carcinogens.Carpenter DO, Bushkin-Bedient S.Exposure to chemicals and radiation during childhood and risk for cancer later in life.J Adolesc Health. 2013;52(5 Suppl):S21-S29. doi:10.1016/j.jadohealth.2013.01.027Jackson M, Marks L, May GHW, Wilson JB.The genetic basis of disease.Essays Biochem. 2018;62(5):643-723. doi:10.1042/EBC20170053National Institutes of Health: National Human Genome Research Institute.Tumor suppressor gene.International Agency for Research on Cancer.Preamble to the IARC monographs on the identification of carcinogenic hazards to humans.Environmental Protection Agency.Facts about formaldehyde.Environmental Protection Agency.Protect against exposures to formaldehyde.Skin Cancer Foundation.UV radiation & your skin.American Cancer Society.Radon and Cancer.American Cancer Society.Understanding radiation risk from medical tests.American Cancer Society.Viruses that Can Lead to Cancer.MedlinePlus.Epirubicin.American Cancer Society.Determining if something is a carcinogen.Turner MC, Andersen ZJ, Baccarelli A, et al.Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations.CA A Cancer J Clin. 2020;70(6):460-479. doi:10.3322/caac.21632American Lung Association.Indoor air pollutants and health.National Cancer Institute.Cancer prevention overview (PDQ)-patient version.National Cancer Institute.Chemicals in meat cooked at high temperatures and cancer risk.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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MedlinePlus.Epirubicin.
American Cancer Society.Determining if something is a carcinogen.
Turner MC, Andersen ZJ, Baccarelli A, et al.Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations.CA A Cancer J Clin. 2020;70(6):460-479. doi:10.3322/caac.21632
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