Environmental Causes of Lung Cancer

Smoking is not the only cause of lung cancer. From radon to air pollution to wood smoke and more, many things that may be in your environment are known to increase the risk of the disease too.

As with smoking, many of these environmental causes of lung cancer can be avoided or reduced once you're aware of them—especially those that may be in your home or workplace.

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Exposure to radon in the home is the second-leading cause of lung cancer in the United States as well as the leading cause in non-smokers.

Radon is a radioactive gas produced by the natural decay of uranium in the soil. It is found throughout the world and can enter homes through cracks in the foundation, via sump pumps and drains, and through gaps around pipes and wires.

No fewer than one of every 15 American homes is believed to have elevated and potentially hazardous radon levels.

The Environmental Protection Agency (EPA) suggests that around 21,000 Americans get lung cancer from radon exposure each year.

You can test your home by using a simple do-it-yourself radon testing kit (available at most hardware stores for about $20 to $30). If the test is strongly positive, a professional clean-up process called radon mitigation can almost always return your home to safe levels.

Secondhand Smoke

According to the Centers for Disease Control and Prevention (CDC), tobacco smoke contains around 7,000 toxic chemicals, 70 of which are known or suspected to be cancer-causing (carcinogens).

Secondhand exposure to these chemicals increases a non-smoker's risk of lung cancer no less than two- to three-fold. In fact, secondhand smoke is responsible for around 2% of lung cancer deaths in the United States, or approximately 7,300 deaths per year.

Even though no-smoking laws have greatly reduced the risk of exposure in public places, you still need to make an extra effort to avoid secondhand smoke at home or at social gatherings.

If you yourself smoke, find a way to quit cigarettes not just for yourself, but for anyone you may live with. There is no such thing as a "safe" amount of secondhand smoke.


Asbestos is a mineral-based substance long used for insulation. It has been banned in the United States for several decades due to its link to different cancers, including mesothelioma.

If left undisturbed, asbestos poses little risk to your health. But if disturbed, particles can be released into the air that are easily inhaled.

This can cause adverse changes to the lining of the lungs, called the pleura, and increase the risk of lung cancer over time.

Asbestos is ordinarily considered an occupational hazard, but it can also be found in homes built pre-1970 (before asbestos was officially banned under the Clean Air Act).

If you choose to remodel an older home that may contain asbestos insulation, hire a certified contractor who can check for asbestos beforehand and remove it safely if found.

Air Pollution

In the United States, air pollution is believed to contribute to around 5% of lung cancers in men and 3% in women.

In parts of Europe, as many as 10% of cases are directly associated with atmospheric pollutants. In China and parts of East Asia, the rate may be as high as 50%.

Among some of the carcinogens commonly found in air pollution are benzene, sulfur dioxide, diesel engine exhaust, formaldehyde, and coal ash.

If you live in a high-density urban area, keep an eye out for air-quality warnings on the news. Stay indoors if a warning has been issued, shutting all doors and windows. If you need to go outside, consider wearing a face mask.

Industrial Chemicals

As with asbestos, exposure to carcinogenic chemicals can sometimes occur in the workplace.

To reduce the risk of exposure, employers in the United States are required to provide employees with Material Safety Data Sheets. These outline all of the hazardous agents used on the premises and ways to reduce the risk of exposure by using protective gear and safety measures.

Common industrial carcinogens include:

  • Arsenic
  • Cadmium
  • Coke oven fumes
  • Chromium compounds
  • Coal gasification
  • Nickel refining
  • Foundry substances
  • Soot
  • Tars
  • Oils
  • Silica

The Occupational Safety and Health Administration (OSHA) outlines all employers' responsibilities with regard to workplace hazards such as these. It also has an online form you can use to file a safety and health complaint with the agency, if needed.

Note, too, that many chemical strippers and solvents available at your local hardware store also contain these same ingredients, albeit in lower concentrations.

To reduce your risk of harm, always read product labels of any solvent or stripper you buy. Heed the safety warnings and adhere to the proper use of the product. This may include wearing gloves, ensuring good ventilation, and putting on a face mask or respirator to avoid inhaling fumes.

Wood Smoke

Exposure to wood smoke may increase the risk of lung cancer. The risk tends to be highest in people exposed to smoke from wood-burning stoves and fireplaces for many years.

Many of those at risk rely on solid fuels like wood, coal, and charcoal for cooking and heat. Those responsible for cooking in such environments—frequently women—are at higher risk.

According to the World Health Organization (WHO), no less than three billion people worldwide rely on solid fuels for cooking and heating. In total, around 17% of lung cancers can be attributed to the burning of these solid fuels.

To reduce your risk, you might consider converting your wood fireplace to gas (whether you use it for cooking or just ambiance).

You should also ensure good ventilation if ever heating with or cooking over a wood or charcoal fire. While a little smoke likely won't do you harm, no one knows for sure how much is safe or unsafe.

Radiation Therapy

While you might not immediately think to lump it into this group, chest radiation for medical purposes is an environmental exposure that can increase the risk of lung cancer.

Examples include radiation therapies used to treat Hodgkin lymphoma (HL) or breast cancer.

Though bladder and rectal cancers are the most common secondary malignancies linked to radiation therapy, lung cancer has also been known to occur.

The risk is highest in people treated for HL who are moderate-to-heavy smokers. By contrast, non-smokers treated with radiation for HL have a five-fold decreased risk of lung cancer.

Despite this, the benefits of radiation therapy generally outweigh the risks. If you are undergoing radiation therapy and are a heavy smoker, let your healthcare provider know and seek help to quit.

If you smoke or have quit within the past 15 years, you may be a candidate for annual lung cancer screening, which is performed with a computerized tomography (CT) scan. The other criteria for screening are age (between 50 and 80) and a 20 pack-year or more history of smoking.

By monitoring the lungs on an ongoing basis, high-risk individuals are more likely to catch cancer early while it is still treatable.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Lemen RA, Landrigan PJ. Toward an asbestos ban in the United States. Int J Environ Res Public Health. 2017;14(11):1302. doi:10.3390/ijerph14111302

  3. Environmental Protection Agency. Health risks of radon.

  4. Centers for Disease Control and Prevention. Secondhand smoke (SHS) effects.

  5. National Cancer Institute. Asbestos exposure and cancer risk.

  6. International Agency for Research on Cancer. Air pollution and cancer.

  7. Eastlake A, Hodson L, Geraci C, Crawford C. A critical evaluation of material safety data sheets (MSDSs) for engineered nanomaterials. Chem Health Saf. 2012;19(5):1-8. doi:10.1016/j.jchas.2012.02.002

  8. Agency for Toxic Substances and Disease Registry. Chemicals, cancer, and you.

  9. World Health Organization. Household air pollution and health.

  10. Dracham CB, Shankar A, Madan R. Radiation-induced secondary malignancies: a review article. Radiat Oncol J. 2018;36(2):85-94. doi:10.3857/roj.2018.00290

  11. US Preventive Services Task Force. Screening for Lung Cancer: US Preventive Services Task Force Recommendation StatementJAMA. 2021;325(10):962–970. doi:10.1001/jama.2021.1117

By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."