Some habits, such as smoking, binge drinking, working with chemicals, being exposed to radiation and the sun, as well as some viruses and bacteria, can raise your chance of getting cancer. When all of these hazards are taken into account, chemical exposures play a minor and as of yet unclear impact in the development of cancer. About how exposure with the majority of chemicals causes cancer, scientists are mostly in the dark.
Carcinogens are substances that are linked to cancer. A carcinogen exposure may not guarantee cancer development. In addition to other factors, it depends on what you were exposed to, how frequently, and how much.
In the late 1700s, a chemical and cancer were first linked. An English doctor observed that many chimney sweeps developed scrotal cancer as a result of exposure to soot, which includes substances called polycyclic aromatic hydrocarbons. Since then, a great deal more substances have been recognized as known or possible cancer-causing agents. Today, employees exposed at work have taught us a lot about the substances that cause cancer in people.
Chemicals and Cancer
Understanding which chemicals cause which cancers is one of our greatest scientific challenges. People are exposed to trace amounts of many chemicals every day. These everyday exposures are usually too small to cause health problems. Exposure to chemicals in the outdoors, at home, and at work may add to your chances of getting cancer. Certain chemicals, including benzene, beryllium, asbestos, vinyl chloride, and arsenic are known human carcinogens, meaning they have been found to cause cancer in humans.
A person’s risk of developing cancer depends on how much, how long, how often, and when they are exposed to these chemicals. When you are exposed is important because a small exposure in the womb, for example, may be more serious than a small exposure as an adult. The genes that you inherit from your parents also play a role.
Some chemicals are known to cause cancer in animals, but they have not been proven to cause cancer in humans. These chemicals are reasonably anticipated to cause cancer in humans and are sometimes called possible human carcinogens. Chloroform, DDT, formaldehyde, and polychlorinated biphenyls (PCBs) are examples of possible human carcinogens.
Getting cancer from a chemical depends on the following:
• The kind of chemical you were exposed to,
• How much of the chemical you were in contact with,
• How long the contact lasted,
• How often you were exposed,
• When you were exposed,
• How you were exposed, and
• Your general health.
How Chemical Exposure Affects the Body
The human body has defenses to guard against all sorts of harmful exposures, including those that may lead to cancer. When something enters your body, it often goes through a process that allows the body to more easily use or get rid of it. This process is called metabolism. Depending on how a chemical is processed, or metabolized, in your body, three types of carcinogens exist:
• Chemicals that can cause cancer (direct acting carcinogens),
• Chemicals that do not cause cancer unless they are changed
when they are metabolized (procarcinogens), and
• Chemicals that do not cause cancer by themselves but can act with another chemical to cause cancer (cocarcinogens).
Damage to DNA in cells can lead to cancer. However, cells can often repair DNA damage. If the damage is extreme, the cells may die. Unrepaired DNA damage can lead to mutations, or changes, in genes, and mutations in certain genes can cause cancer. You can also inherit mutations. Because cancer has a long latency period, determining which exposure, if any, may have led to a mutation is difficult. Therefore we know very little about specific causes of cancers.
Since many cancers are prevalent illnesses, communities experience them frequently. In each given area or workplace, we anticipate discovering a number of cancer cases. We have a solid understanding of how many cases to anticipate in a specific place during a specific period of time since the majority of malignancies are recorded in national databases. However, the presence of several cancer cases in a community might worry locals a lot. If multiple people in a neighborhood are affected by cancer, people could believe there is a cancer cluster there. They could think the problem is caused by anything in the surrounding area.A cancer cluster occurs when more persons than would typically be anticipated in a given geographic region get the same kind of cancer or associated malignancies over an extended period of time. However, what can seem to be a cluster might really represent the anticipated number of cancer cases in the region or group, or it might just be the result of random chance. If the cancer discovered is often uncommon, clusters may be suspected. For instance, because mesothelioma only develops in those who have been exposed to asbestos, localities with high asbestos exposure have seen a high number of mesothelioma cases.
Cancer clusters are rare, especially those that are linked to an environmental exposure. When a group of cancers is linked to an environmental exposure, it is usually because of the conditions below:
- Many more cases than expected of one specific type of cancer or related cancers have been found.
- The cancer is found in an age group in which it is not usually found.
- The type of cancer is rare.
- Scientific evidence supports the link between the chemical in question and cancer.
It might be difficult to determine exactly how much of a cancer-causing material a population has been exposed to. For instance, it might be challenging to link health effects to a particular chemical exposure since many hazardous waste sites include many chemicals. Do not forget that not all substances are dangerous. Additionally, just because a substance is present in the environment close to where you live or work does not guarantee that it has made its way inside of you.To learn more about cancer clusters, environmental health concerns, and toxic chemicals where you live or work, go
Risk Factors for Cancer
More than 200 types of cancer have been identified. Many risk factors—such as age, genetics, or lifestyle choices—can add to your chance of getting cancer. Cancer is usually not caused by only one risk factor but by several of them. The more risk factors you have, the higher your risk of getting cancer.
The most important risk factors are
- Age: Although people of all ages can get cancer, older people are at greater risk.
- Genetics: Your family history may put you at risk for cancer. If you or someone in your family had a certain type of cancer, you may be more at risk for that type of cancer. Genetics play a large role for many cancers, such as breast cancer and colon cancer.
- Behaviors: Tobacco use and exposure to the sun or other sources of UV radiation are risk factors for cancer. Other lifestyle choices that might affect your chances of getting cancer include a poor diet, lack of exercise, or heavy drinking.
- Viruses or bacteria: Some cancers are caused by a virus or bacteria. Some viruses linked to cancer are the human papillomavirus (HPV), which causes cervical cancer; hepatitis B and C viruses, which can cause liver cancer; and the Epstein-Barr virus, which may cause a type of lymphoma. Also, the H. pylori bacterium can cause gastric cancer.
- Exposure to chemicals: As we have discussed, being exposed to chemicals may also be a risk factor.
Behavioral Risk Factors
Diet & Exercise
Maintain a healthy body weight and live an active lifestyle. Obesity is associated with an increased risk of cancers of the breast, colon, kidney, and esophagus. Physical activity may also lower your risk for some cancers, including cancers of the colon and breast. See this article to learn more about nutrition, physical activity, and obesity.
Medical Tests and Treatments
Your chance of developing cancer may rise as a result of several medical procedures, such as some imaging examinations. Women may be more likely to develop breast or uterine cancer as a result of hormones and hormone-related medications, such as menopausal hormone treatment. Even certain cancer therapies, such as medication and radiation, have been demonstrated to raise the patient’s risk of developing the disease again. Discuss the advantages and disadvantages of medical testing and treatments with your doctor.
Exposure at Work
Jobs that put workers at high risk for cancer include uranium miners, asbestos workers, shipbuilders, certain factory and chemical plant workers, and workers in nuclear industries. Workers can also bring home contamination on their clothing, shoes, or skin, which can potentially put others who share a home or car at risk. Visit cdc for more information on workplace safety.
Pollution & Exposure to Chemicals
Exposure to some chemicals and hazardous substances can increase the risk of cancer. A few well-known carcinogens are asbestos, nickel, cadmium, radon, vinyl chloride, benzidene, and benzene. These carcinogens may act alone or with another carcinogen to increase your risk. For example, asbestos workers who also smoke have a higher risk of lung cancer. Visit cdc for more information on specific chemicals and your health.