Summary of Key Points:

  • Lung cancer is expected to be the leading cause of cancer death in Canada in 2023, with radon gas being a leading cause of lung cancer in Canada, particularly for people who do not smoke tobacco. However, there are several other major causes of lung cancer people should be aware of in order to reduce their risk.
  • Smoking tobacco products is the single largest cause of lung cancer in Canada, contributing to nearly 85% of all lung cancer deaths. Combined exposure to radon gas and tobacco smoke make the chances of lung cancer much more likely.
  • Radon is a soil gas produced when minerals containing uranium, thorium or radium break down. It creates a significant risk of lung cancer when it becomes concentrated in buildings, which is why we urge homeowners to test the radon levels in their homes.
  • PM2.5 (“particulate matter of 2.5 microns in size”) is a kind of air pollution caused by hydrocarbon combustion, and can be produced by automobiles, forest fire smoke, solid fuel burning, as well as other natural and industrial processes. Since exposure to PM2.5 increases your risk of lung cancer, it’s advised to reduce your exposure to environments where these dangerous particles are present in high concentration.
  • Arsenic is a naturally occurring heavy metal that is found in natural abundance in some areas of Canada, and can also be produced in large amounts by industry. Long-term exposure to arsenic in water and water vapours increases your risk of lung cancer via lung fibrosis and bronchitis. It is recommended to test your drinking water for arsenic and use a filtration system to reduce its levels if necessary.
  • Severe and/or ongoing (chronic) lung inflammation from infections such as tuberculosis or pneumonia, or diseases such as COPD are also linked to an increased risk of lung cancer. “Taking steps towards avoiding severe lung infection outcomes, either through changes in behaviour, hygiene, vaccination, and/or timely medication may help you avoid this.”

Lung cancer is expected to be the leading cause of death by cancer in Canada in 2023, accounting for approximately one in every four cancer-related deaths. Since radon is the leading cause of lung cancer in Canada among people who do not use tobacco products, we at the Evict Radon National Study work to educate Canadians about its risks and encourage proper radon testing in homes across the country.

However, there are numerous other causes of lung cancer as well, and as scientists dedicated to providing information that can be used to improve the health of Canadians, we want you to be aware of them. Below, we’ve listed five of the most significant causes of lung cancer—including radon—and provided suggestions for reducing your risk.

Want to know your home’s radon levels? Order a 90 day radon test kit here.

Via Adobe Stock.

#1: Tobacco

Smoking tobacco is the leading cause of lung cancer in Canada, responsible for about 85% of all lung cancer deaths and approximately 30% of all cancer deaths overall. Long-term smoking increases the risk of lung cancer by as much as 20-30 times.

Although smoking and radon exposure are independent risk factors for lung cancer, smoking tobacco can make lung cancer from radon exposure more likely, with risk from each being not 1+1=2, but closer to 1+1=17. Tobacco smoke damages the cells in the lungs, making them more susceptible to the harmful effects of radon, and vice versa. As a result, the risk of lung cancer is much higher for tobacco smokers who are exposed to radon than for people who do not smoke tobacco, and who are exposed to the same levels of radon.

Quitting smoking tobacco greatly reduces the risk of developing lung cancer. Furthermore, if you are a tobacco smoker and are exposed to radon, you should strongly consider quitting smoking and taking steps to reduce your radon exposure to minimize your risk of lung cancer.

Via Evict Radon.

#2: Radon Gas

Radon is a naturally occurring, radioactive gas released from the soil when minerals in the ground containing uranium, radium, or thorium break down. Radon can then be drawn up and into homes and buildings through cracks and gaps in the foundation, where it can become concentrated and reach dangerous levels that increase lifetime lung cancer risk.

All homes contain some amount of radon, but reliable testing is required to determine whether the levels in a given building pose a significant lung cancer risk and whether they need to be mitigated. Radon levels are measured in Becquerels per cubic metre (Bq/m3), and their risk level can be assessed as follows:

  • Low risk: <100 Bq/m3
  • Medium risk: 100 – 199 Bq/m3
  • High risk: 200 Bq/m3

Learn more about what different radon levels mean here.

Long term exposure to radon levels that are over 100 Bq/m3 constitutes a significant increase in the lifetime risk of lung cancer, so even ‘medium risk’ homes should take steps to reduce their radon levels. Learn more about interpreting radon test results here.

Because radon exposure accounts for over 3,300 deaths nationwide each year, it’s vital to test your home with a Health Canada recommended long-term testing kit, and arrange for a C-NRPP certified radon mitigation professional to reduce the levels if they are too high. This is the single best way to lower your risk of lung cancer from radon exposure.

Via Adobe Stock.

#3: PM2.5 (Combustion Pollution)

PM2.5, or particulate matter of 2.5 microns in size, is a type of air pollution caused by combustion of hydrocarbons. It is produced by numerous natural and man-made technologies and processes, including:

  • Woodsmoke burning (forest fires, campfires)
  • Coal-fired power plants
  • Natural gas-fired power plants
  • Industrial boilers and furnaces
  • Automobile engines
  • Diesel engines (in vehicles and equipment)
  • Residential wood burning fireplaces or stoves
  • Biomass burning

Research shows that long-term exposure to PM2.5 increases the risk of lung cancer. The best way to reduce your risk is to avoid exposure to PM2.5 by staying indoors on days with high air pollution and supporting government policies that aim to reduce air pollution.

Via Adobe Stock.

#4: Arsenic

Arsenic is a naturally occurring heavy metal element that can be found in soil, water, and air. It can also be released into the environment through industrial activities such as mining and smelting. When water vapor containing arsenic is inhaled, it can cause damage to the DNA in the lung tissue, which can increase lifetime risk of lung cancer.

Similar to radon exposure, combined Arsenic and tobacco smoke exposure multiplies risk of lung cancer. Studies have shown that tobacco smokers who are exposed to high levels of arsenic have a much higher risk of developing lung cancer than anyone who is not exposed to arsenic.

Long-term exposure to arsenic can also lead to lung fibrosis and bronchitis, which can increase the risk of lung cancer. The main areas of concern for arsenic exposure in Canada are in the North and Atlantic regions, although trace amounts of arsenic can be found in water and soil in almost any location. One way to reduce your risk is to have your drinking water tested and take steps to reduce exposure if high levels are found, such as using a water filtration system.

Via Adobe Stock.

#5: Severe or Chronic Lung Inflammation

Studies have found a link between severe and/or chronic lung inflammation and an increased risk of lung cancer. The main risk factors that can cause inflammation in the lungs that have an effect on lung cancer risk include:

  • Exposure to airborne irritants and pollutants such as tobacco smoke, asbestos and other silicates, smog, dust, chemical fumes, and mold
  • Severe lung inflammation arising from infections such as pneumonia, tuberculosis, and influenza
  • Inflammation associated with COPD (chronic obstructive pulmonary disease)
  • Idiopathic pulmonary fibrosis (IPF)

It’s important to note that lung inflammation can also be a symptom of other underlying health conditions such as heart failure, lung infections, and lung cancer itself. To reduce the risk, individuals should take steps to reduce exposure to pollutants and manage any chronic respiratory conditions they may have.

Know Your Lung Cancer Risks & Actively Reduce Them

Knowing about these leading causes of lung cancer empowers you to take active measures to lower your risk. Quitting smoking tobacco, testing your home for radon with a long-term testing kit (and having your radon levels mitigated by a certified professional if necessary), limiting your exposure to PM2.5 from natural or human-made sources, testing your drinking water for arsenic, and doing what you can to address conditions or reduced chances of lung inflammation are all recommended in order to minimize your likelihood of developing lung cancer.

To measure radon levels in your home with a long-term test approved by Health Canada and become a citizen scientist participating in our national study to raise awareness about radon risks across Canada, reach out to The Evict Radon Radon National Study. We’ll be happy to help you learn more about how to avoid dangerous radon exposure in your home.