Smoking is one of the main risk factors for non-small cell lung cancer (NSCLC). Other factors include exposure to radon or asbestos and a family history of lung cancer.

You can take steps to manage some risk factors, such as smoking. However, it is not possible to avoid some other risk factors, such as a personal or family history of lung cancer.

Read on to learn more about the risk factors for NSCLC. This article also looks at ways to help prevent or reduce the likelihood of this type of cancer.

Tobacco smoking is the main cause of lung cancer. According to the American Cancer Society, smoking is the cause of about 80% of lung cancer cases and 80% of deaths due to lung cancer.

NSCLC is the most common type of lung cancer, accounting for about 90% of lung cancer cases. This means that a high number of NSCLC deaths may have links to smoking.

Smoking for longer or smoking more packs of cigarettes per day will also increase the risk of NSCLC.

In addition to smoking typical cigarettes, smoking tobacco in the following forms may increase the risk of developing NSCLC:

  • pipes
  • cigars
  • menthol cigarettes

Exposure to secondhand smoke at work or at home also increases the risk of developing lung cancer by 20% to 30%.

Exposure to radon can increase your risk of NSCLC.

Radon is a natural radioactive gas that is produced when uranium in rocks and soil breaks down.

According to the Environmental Protection Agency (EPA), radon is the second leading cause of lung cancer. It causes around 21,000 lung cancer deaths each year in the United States. In about 2,900 of those cases, the person has never smoked.

Indoor exposure to radon is more likely to increase your risk of NSCLC than outdoor exposure. Radon levels in basements can be particularly high.

Exposure to asbestos can increase your chances of developing NSCLC.

This risk is greater in people who smoke, but anyone with frequent exposure to asbestos, such as workplace exposure, has an increased risk of NSCLC.

Asbestos exposure might occur in occupations such as construction and shipyard work. If you’re at risk of working with or near asbestos, your employer must provide personal exposure monitoring and personal protective equipment (PPE).

Other substances that can increase the risk of NSCLC include:

  • uranium and other radioactive ores
  • diesel exhausts
  • arsenic in drinking water, particularly in Southeast Asia and South America
  • inhaled chemicals, such as:
    • arsenic
    • beryllium
    • cadmium
    • chloride
    • chromium compounds
    • chloromethyl ethers
    • coal products
    • mustard gas
    • nickel compounds
    • silica
    • vinyl

Air pollution may increase the risk of NSCLC. This is more likely to happen if you live in a city.

Around 1% to 2% of lung cancer deaths in the United States could be due to air pollution outdoors.

If you have a personal history or family history of lung cancer, it may increase your risk of NSCLC.

However, according to a 2024 research review, few studies have looked at the impact of a positive family history of cancer in people with NSCLC. A positive family history of cancer means that a close relative has received a cancer diagnosis.

The review authors also mention that the studies did not assess the clusters of other risk factors that members of the same family might have been exposed to. This means that while NSCLC may run in families because of certain genes in some cases, it could also develop if relatives experience the same risk factors, such as smoking or radon exposure.

Some medical conditions, such as the following, may increase the likelihood of developing NSCLC or another type of lung cancer:

Talk with your doctor if you have concerns about conditions or other factors that may increase your risk of NSCLC.

It may not always be possible to prevent NSCLC or lung cancer in general, but you can take steps to reduce some of the risks.

Ways to help reduce your chances of developing NSCLC include:

  • quitting smoking (if applicable)
  • avoiding secondhand smoke
  • avoiding radon exposure
  • minimizing workplace exposure to asbestos and other substances, such as by wearing appropriate PPE

Your doctor can provide more information about ways to manage your risk of NSCLC based on your individual circumstances.

Smoking is the main risk factor for non-small cell lung cancer (NSCLC). Radon exposure can also significantly increase your risk of developing this type of cancer.

Other NSCLC risk factors include exposure to asbestos and other substances, air pollution, a family history of lung cancer, and certain medical conditions, such as pneumonia and COPD.

It may not always be possible to prevent NSCLC. But certain steps, including quitting smoking and avoiding secondhand smoke exposure, can help reduce your chances of developing it.