Lung Cancer Without Smoking?

We know cigarette smoking is responsible for approximately 80% to 90% of all lung cancer cases and deaths in the United States. Fortunately, cigarette smoking – often portrayed as alluring in movies and TV – is fading. The number of adult smokers in the United States fell to a record low in 2024, according to the American Lung Association. 

This is good news. However, statistics reveal another concern: one in four lung cancer cases worldwide arise in people who never smoked. The underlying factors are becoming more understood.

“Lung cancer in never-smokers is seen most often in women, people of Asian descent, and people with a family history of lung cancer,” says radiation oncologist Dennis M. Sopka, MD, Chief, Division of Radiation Oncology with Lehigh Valley Topper Cancer Institute, part of Sidney Kimmel Comprehensive Cancer Center and Jefferson Health. “Additionally, there are environmental- and occupational-related causes of lung cancer present in the never-smoking group.”

Scientists found that people who have had high exposure to fine-particle air pollution were 1.6 times more likely to have mutations in the gene that helps suppress tumors. 

Particle pollution comes in many sizes and shapes and can be made of different components, including acids (such as sulfuric acid), inorganic compounds (such as ammonium sulfate, ammonium nitrate, and sodium chloride), organic chemicals, soot, metals, soil or dust particles, and biological materials (such as pollen and mold spores).

“Fine-particle air pollution has also been shown to damage to the protective DNA caps at the ends of chromosomes. This damage has been linked to cancer, organ failure, and other health risks,” Dr. Sopka says. 

The most common nonsmoking risk for lung cancer involves asbestos. It’s a fibrous material often used for insulation or as a fire retardant in buildings during the 20th century. That is, until its health hazards became known. 

“Inhalation of asbestos fibers can lead to serious diseases such as asbestosis, lung cancer, and mesothelioma, a cancer that affects the protective tissue lining internal organs,” Dr. Sopka says. “People with these diseases were usually exposed to high levels of asbestos for a long time, with symptoms appearing 20 to 30 years after their first exposure.”

As the dangers were recognized, federal and state agencies enacted regulations to control the use, handling, and removal of asbestos-containing materials. In Pennsylvania, the state government enforces a comprehensive set of laws for contractors and inspectors aimed at protecting workers, residents, and the environment from asbestos-related risks. 

The Pennsylvania Department of Environmental Protection (DEP) does not regulate the removal of asbestos-containing materials from private residences unless the residence is a multiple-unit apartment building. The DEP advises people to contact their township or borough to find out about local regulations.

A known human carcinogen, radon is another serious risk for lung cancer. It’s an odorless gas that occurs naturally as a radioactive decay product of radium. Radon can enter your home from the ground through cracks in the foundation.

Pennsylvania has a serious radon problem. Approximately 40% of homes tested in Pennsylvania have radon levels above the DEP’s action guideline (4 picocuries per liter). Now, testing water and indoor air for radon has become a routine, mandatory step during home sales and real estate inspections.

Dr. Sopka recommends a radon test for your home or property if you’ve never had one or you’re unaware of previous results. To learn more about home testing, contact the DEP Radon Division:

Radon Hotline: 800-237-2366
Phone: 717-783-3594
Website: Radiation Protection | Department of Environmental Protection | Commonwealth of Pennsylvania

You can find radon test data specific to Pennsylvania ZIP codes here.

If you work around chemicals regularly, clinicians urge taking precautions. There are an estimated 80,000 chemicals in use in the U.S. If your workplace doesn’t require a mask when working with chemicals, it’s wise to invest in one.

Another thing to avoid is someone else’s smoke. The Centers for Disease Control and Prevention says there is no safe level of exposure to secondhand smoke; even brief exposure can cause harm. Health problems that can result are heart disease, stroke, and lung cancer, as well as reproductive effects in women, including low birth weight in babies. 

Dr. Sopka wants to let patients and others know that lung cancer isn’t just confined to smokers, but that smokers should be extra cautious and kick the habit. 

“By the time symptoms like a chronic cough, shortness of breath, fatigue and weight loss occur, the disease already has progressed,” he says. “What we do know is, as with smoking, prolonged exposure to any of these materials adds to lung cancer risk. It’s critical to your health and longevity to limit your exposure to any of them if possible.”

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