Lung cancer is the second most common cancer, according to the American Cancer Society (ACS). It accounts for about 14 percent of all new cancers. There will be an estimated 222,500 new cases of lung cancer in the United States in 2017.

Lung cancer is associated with smoking, but it can also develop in nonsmokers. Smoking increases the risk of lung cancer. Yet roughly 20 percent of people who die from lung cancer in the United States don’t smoke or use tobacco products.

Protect yourself from this deadly disease by learning about the nonsmoking causes of lung cancer.

Secondhand smoke

You can develop lung cancer from exposure to secondhand smoke. Cigarette smoke contains toxins known to damage the lungs and cause cancer. Inhaling these toxins through secondhand smoke can also damage the lungs.

Secondhand smoke can occur if you live with someone who smokes or if you’re often around smokers. Some public places ban smoking inside buildings, which can help prevent cancer from secondhand smoke.

Avoid areas with heavy smoke to prevent breathing in harmful toxins. Also, make sure others don't smoke inside your home or car.

Radon gas

Radon is a cancer-causing gas that you can’t see, smell, or taste. This gas is found in rocks and soil. Some homes and buildings are built on top of land containing radon.

Living or working in a radon-contaminated building doesn't mean that you'll develop lung cancer. But cancer can develop from long-term exposure to this gas. Breathing in the gas slowly damages your lungs, causing the growth of cancer cells. Radon gas is the second leading cause of lung cancer in the United States.

Some people living and working in contaminated buildings are unaware of the danger. To know your risk, you have to have the building tested for this gas.

If a radon gas test reveals a level greater than 4 picocuries per liter, take steps to fix the problem. Reduce radon gas levels by installing a vent fan that draws out radon from your home or office. Also, seal or caulk cracks around to prevent radon from entering the building.

Occupational exposure

Lung cancer can also develop from long-term exposure to harmful chemicals or substances. These include asbestos, diesel exhaust, arsenic, coal, and nickel. Like radon gas and secondhand smoke, breathing in these toxins can damage your lungs and cause cancer.

Keeping the air-quality in your workplace clean can prevent lung damage and lung cancer. To reduce your risk, work in well-ventilated areas if possible. Wear equipment to protect your lungs from dust, exhaust, fumes, and other pollutants that could cause life-threatening damage.

Protective equipment includes a face mask or a respirator worn over your nose and mouth. This cleans the air before it enters your body.

Signs of toxic exposure at work include a persistent cough, a runny nose, or a dry, scratchy throat.

Outdoor air pollution

Outdoor air pollution may also increase the risk of cancer. Outdoor air pollution can include metal, dust, engine exhaust, agriculture emissions, transportation, and industrial emissions.

The ACS reports that the risk of lung cancer associated with outdoor pollution is low in the United States, but still possible. Lung cancer forms from pollution when the body can’t rid certain harmless particles. Small particles can become trapped in the lungs, causing damage over time.

Avoiding lung cancer caused by pollution is difficult. To protect yourself, limit outdoor activity with pollution levels are high. According to the American Lung Association (ALA), the risk of lung cancer from pollution is higher in children, the elderly, those who work outdoors, and people with lung disease, heart disease, and diabetes.


Genetics can determine how your cells grow and divide. Some people inherit DNA mutations that increase their risk of developing certain cancers. Genetics can also make it difficult for your body to rid pollutants that cause lung cancer. A strong family history of lung cancer raises the risk of the illness. If you have a parent, a sibling, or several relatives with lung cancer, you may also develop this cancer despite never smoking.

You can’t control genetics, but you can protect yourself by not smoking and avoiding harmful indoor and outdoor air pollution, as well as secondhand smoke.


Never having smoked doesn’t mean you’re safe from lung cancer. This disease can occur in nonsmokers, hence the importance of recognizing symptoms of the disease. Symptoms include a persistent cough, coughing up blood, lack of energy, and unexplained weight loss.

The survival rate for lung cancer depends on the stage it is when diagnosed. Early diagnosis and treatment are key for the best possible outcome.