Toxins in Tobacco Smoke

The toxic chemicals in tobacco smoke can harm nearly every organ in the body.^{Footnote 1} About 80 of these chemicals are cancer causing.^{Footnote 2}

• Key facts about toxins in tobacco smoke
• What are the toxins in tobacco smoke?
• How does quitting reduce the risk of disease?
• Health benefits of quitting tobacco use at any age
• Call for free help to quit

Key facts about toxins in tobacco smoke

• Tobacco use is a known or probable cause of more than 40 debilitating and often fatal diseases of the lungs, heart, and other organs.^{Footnote 3}
• There is no safe level of exposure to tobacco smoke. Cigarette filters do not keep toxic smoke out of the body.^{Footnote 2}
• Tobacco smoke contains toxic chemicals such as carbon monoxide, formaldehyde, and hydrogen cyanide.^{Footnote 2}
• Exposure to the toxins in second-hand smoke can lead to cancer, heart and lung diseases, and poor health in infants and children.^{Footnote 1}
• Inhaling ten puffs per cigarette and using ten cigarettes a day means harmful chemicals enter the body 36,500 times in a year.

View health-related messages for all tobacco product packaging.

What are toxins in tobacco smoke?

Tobacco smoke contains over 7,000 chemicals, including about 80 chemicals known to cause cancer. Some of these chemicals are found naturally in tobacco. Others are formed through combustion or burning.^{Footnote 2Footnote 4Footnote 5} Exposure to these chemicals occur whenever a tobacco product is burned or smoked.

There are several major toxins in tobacco smoke: tar, carbon monoxide, formaldehyde, hydrogen cyanide, benzene, cadmium and nicotine.

Tar

Tar is a sticky, brown residue in tobacco smoke containing hundreds of chemicals. Many of these are known to cause cancer.^{Footnote 5} It is not the same as the tar used on road surfaces or roofing. Tar is released in tobacco smoke as small particles, which can pass through cigarette filters and be inhaled into the lungs.

The tar in tobacco smoke paralyzes and can eventually kill cilia in the lungs. Cilia are tiny, hair-like structures lining the airways to help clean out particles and pollutants. Damaged cilia are less effective at clearing tobacco smoke and other pollutant particles from the lungs, making people who smoke more susceptible to lung disease.^{Footnote 6}

Carbon monoxide

Carbon monoxide is in tobacco smoke as a result of burning tobacco. It reduces the ability of the red blood cells to deliver oxygen to tissues, causing damage to the body, especially the cardiovascular system.^{Footnote 2} This colourless, odourless, and potentially fatal gas is also found in automobile exhaust and released by poorly maintained furnaces.

Formaldehyde

The International Agency for Research on Cancer says formaldehyde is a known cancer causing substance in humans.^{Footnote 7} In people exposed to tobacco smoke, formaldehyde contributes to symptoms such as eye, nose and throat irritation. Formaldehyde can cause nasopharyngeal cancer, cancer of the nose, oral cavity, and throat.^{Footnote 8}

Hydrogen cyanide

Considered one of the most toxic agents in tobacco smoke, many short and long-term toxic effects of tobacco smoke are associated with hydrogen cyanide. Inhaling hydrogen cyanide may result in weakness, restlessness, nausea, and vomiting.^{Footnote 9} Hydrogen cyanide also damages cilia, the lungs' natural cleaning system, allowing foreign particles and harmful chemicals to accumulate in the respiratory tract.^{Footnote 10}

Benzene

The International Agency for Research on Cancer says benzene is a toxic compound and known cancer causing substance in humans.^{Footnote 7} Long-term exposure to benzene can harm the bone marrow, where new blood cells are made.^{Footnote 11Footnote 12} This can result in a low red blood cell count, causing anemia. Benzene exposure is also associated with a higher risk of leukemia, a cancer that develops in the bone marrow.^{Footnote 13}

Cadmium

The International Agency for Research on Cancer says cadmium is a cancer causing heavy metal found in tobacco smoke that can damage the cells lining the blood vessels of the body.^{Footnote 14} High levels of cadmium in the body contribute to heart disease and lung cancer.^{Footnote 2Footnote 15}

Nicotine

Nicotine occurs naturally in tobacco plants. It is the known addictive drug in tobacco products. Nicotine interacts with the brain to create pleasurable sensations, reinforcing the urge to use more tobacco.^{Footnote 16} While nicotine is not a major cause of tobacco-related diseases, it keeps people who smoke hooked on tobacco products and exposed to other harmful components of tobacco smoke. Nicotine can also harm the health of unborn babies and contributes to preterm delivery and stillbirth.^{Footnote 1} It can be particularly damaging to brain development in children, up to and including the teen years.

How does quitting reduce the risk of disease?

Quitting is one of the best ways to avoid tobacco-related diseases caused by toxins in tobacco smoke. It is the most important thing someone who smokes can do to improve their health.^{Footnote 17}

The following diseases or conditions are related to tobacco use:^{Footnote 1Footnote 17Footnote 18Footnote 19}

• Cancer of the blood, lung, mouth, voice box, throat, kidney, bladder, liver, pancreas, cervix, stomach and bowel
• Heart disease, circulatory problems, and stroke
• Lung disease including chronic obstructive pulmonary disease (COPD) such as emphysema and chronic bronchitis
• Tooth loss, gum disease, and vision loss
• Liver damage, type II diabetes, and gangrene
• Impotence and irregular menstruation or menopause
• Infertility
• Sudden infant death syndrome and infant health problems.

Health benefits of quitting tobacco use at any age

Quitting tobacco use reduces the risk of premature death, improves health, and enhances quality of life.^{Footnote 17} Quitting at any age is beneficial to one's health and lowers one's risk for many diseases, including heart and respiratory disease, cancer, and reproductive diseases.^{Footnote 17} Even people who have smoked or used tobacco heavily for many years benefit from quitting.^{Footnote 17Footnote 18}

Read more about the benefits of quitting smoking.

Call for free help to quit

Call the toll-free pan-Canadian quit line at 1-866-366-3667. Quit line counselling, alone or in combination with cessation medications, increases success in quitting.^{Footnote 17}