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Risk factors for lung cancer

It's a fact: anyone with lungs can get lung cancer. Smoking tobacco is the #1 risk factor. Exposure to certain chemicals and your family health history can also increase your risk.



Smoking tobacco is the # 1 risk factor for developing lung cancer. Every year, 30,000 Canadians are diagnosed with lung cancer. Tobacco use is responsible for more than 70% of these cases.

If you smoke, the most important thing you can do to lower your risk is to quit. Speak to your healthcare provider about options to help you quit and visit for more information.

If you smoke and you are exposed to another risk factor (such as radon or asbestos), you are at much higher risk for lung cancer.


Second-hand smoke

Second-hand smoke contains the same harmful chemicals that are inhaled by someone who smokes. It is the cause of more than 800 lung cancer deaths in Canada every year.

Third-hand smoke is smoke that builds up on surfaces such as walls, rugs,
curtains, furniture or surfaces in vehicles; it is also a health concern.



Radon is second leading cause of lung cancer in Canada.

Radon is a colourless, odourless, tasteless gas that comes from the natural breakdown of uranium in rocks and soil. It can seep into buildings through dirt floors or cracks in the foundation and build up in enclosed, poorly ventilated spaces.

Radon can build up in your home and put you and your family at increased risk for lung cancer. It is the leading cause of lung cancer in non-smokers and the second leading cause of lung cancer in smokers.

If you smoke and you are exposed to radon, you are at much higher risk for lung cancer.

Find more about radon and our Lung Matters Home Radon Mitigation programs.


Outdoor air pollution

There is increasing evidence that longer-term exposure to particle pollution from vehicle exhaust, coal-fired power plants and other industrial sources is connected to an increase risk of lung cancer.

In Canada, more than 15,000 premature deaths each year are linked to air pollution. The transportation sector is a leading source of harmful air pollution, accounting for 25% of our greenhouse gas emissions.

Read more about diesel emissions and their impact on children.


Chemicals in the workplace

Some occupations, such as certain manufacturing jobs, the construction
industry, mining and oil and gas industries and in welding and motor vehicle
repair, involve an increased risk of exposure to substances that have been
proven to cause cancer in humans (carcinogens).

If you smoke and you are exposed to an occupational carcinogen, you are at much higher risk for lung cancer.

Common workplace carcinogens include arsenic, asbestos, chromium IV, diesel engine exhaust, crystalline silica, lead, polycyclic aromatic hydrocarbons (PAHs) and welding fumes



Personal or family health history

A personal history of lung cancer or a personal history of lung disease (like chronic obstructive pulmonary disease or tuberculosis) can make your lungs more vulnerable to developing lung cancer.

Having a first-degree relative (parent, child, sibling) who has been diagnosed with lung cancer can also increase your risk.


This section was made possible by an unrestricted educational grant from Merck Canada, Sanofi Canada and Astra Zeneca Canada.

Printable resources

Lung cancer risk and screening