When you think of lung cancer, chances are what immediately comes to mind is smoking. And it should: Up to 80% of lung cancer deaths are thought to result from smoking, according to the <a target="_blank" href="http://www.netreturns.biz/healthinfo/bouncelink.aspx?shortcut=cancersoc">American Cancer Society</a> (ACS). 
But lung cancer can also occur in nonsmokers. These cancers can result from certain substances in the environment&mdash;both indoors and outdoors&mdash;that are breathed into the lungs.
Why it happens
As with all cancers, lung cancer begins when the genetic material in cells is damaged. There are several possible causes for this damage.
Genetics. A family history of lung cancer may slightly raise your risk for the disease, especially if the person was diagnosed at a younger age.
Carcinogens. Most lung cancer in nonsmokers comes from breathing cancer-causing substances in the workplace or home. The ACS and other medical experts list these common carcinogens:
<ul>
 <li>Radon. This odorless, colorless gas is the second-leading cause of lung cancer in the U.S. It rises from the soil and can enter buildings through gaps or cracks in the foundation. About 1 in 15 homes in the U.S. has excessive levels of radon and may benefit from a venting system to reduce the risk.</li>
 <li>Asbestos. People who work with asbestos&mdash;such as in mines, mills and shipyards&mdash;are at higher risk for lung cancer. They also have a greater risk for developing mesothelioma, a type of cancer that starts in the lining of the lungs. Home remodeling can also release asbestos fibers and create a risk.</li>
 <li>Other workplace substances, such as arsenic, vinyl chloride and diesel exhaust, can cause lung cancer if they are inhaled.</li>
 <li>Air pollution. Smoke, vehicle exhaust and other types of pollution can cause lung cancer. The <a target="_blank" href="http://www.netreturns.biz/healthinfo/bouncelink.aspx?shortcut=who">World Health Organization</a> classifies outdoor air pollution as a carcinogen.</li>
 <li>Secondhand smoke. Cigarettes affect more than the smoker. Each year, about 7,000 adults die of lung cancer from breathing secondhand smoke.</li>
</ul>
Reduce your risk
If you are a nonsmoker, you already avoid the most common cause of lung cancer&mdash;smoking. But there are other steps you can take to further lower your risk of this deadly disease. 
Buy a do-it-yourself testing kit to measure the amount of radon in your home. Or hire a professional to do it. If radon is a problem in your home, you can take steps to reduce it. The <a target="_blank" href="http://www.netreturns.biz/healthinfo/bouncelink.aspx?shortcut=epa">Environmental Protection Agency</a> recommends hiring a qualified contractor to fix your home because lowering radon levels requires special knowledge and skills.
Also, stay away from secondhand smoke as best as you can. Don't allow smoking in your home or car.
Focus on eating more produce. According to the ACS, some evidence suggests that a diet high in fruits and vegetables may protect against lung cancer in both smokers and nonsmokers.
Finally, find out if any cancer-causing agents are being used in your workplace and how you can reduce your exposure to them.
Reviewed 7/31/2023

Don't smoke? You can still get lung cancer

Thousands of nonsmokers are diagnosed with lung cancer every year. Learn what you can do to reduce your risk.