The best ways to prevent lung cancer are to avoid smoking and to limit exposure to certain pollutants.
Smoking and Lung Cancer
Cigarette smoking is unquestionably the single greatest controllable risk factor for lung cancer and the most common preventable cause of all premature deaths in the United States. Half of all smokers die prematurely of diseases related to smoking.
While smoking cigars and pipes greatly increases the danger of cancers of the mouth, pharynx, larynx, and esophagus, the risk of lung cancer is not as high as with cigarette smoking, because pipe and cigar smokers usually do not inhale as deeply or as frequently as cigarette smokers. The risk of lung cancer is greatest in those who start smoking at an early age and smoke the most cigarettes daily.
Because the risk of lung and other cancers gradually diminishes after people stop smoking, you can benefit from quitting at any age. The benefit in reducing the risk of lung cancer becomes evident after about five years. The risk of developing lung cancer continues to decrease the longer a person does not smoke, but it never falls as low as the risk level of a lifelong nonsmoker.
Radon and Lung Cancer
Many studies have examined the risk of lung cancer posed by radon in the home. Scientists estimate that approximately 15,000 to 22,000 lung cancer deaths per year are related to radon. The U.S. Environmental Protection Agency (EPA) recommends measuring radon levels in homes and reducing the levels when they exceed 4 picocuries per liter (pCi/L) over a year, a level estimated to be present in about 5 percent of American homes.
Some critics disagree with this EPA recommendation, arguing that these levels of radon do not pose a significant risk and that attention should be focused on finding the homes with the highest levels. Recently, researchers estimated that reducing radon levels in all homes with readings higher than 4 pCi/L would result in 2 to 4 percent fewer lung cancer deaths.
To determine whether radon levels are high in your area, call your local EPA office. Taking a radon measurement in an individual house is the only definitive way to know the radon level, and several inexpensive kits are available in most hardware stores. Etched-track or electret detectors are good choices; the best of these kits take measurements over at least a three-month period. The label on the kit should say that it meets EPA requirements or is certified by your state.
If it is necessary to reduce radon levels in your home, contact a state-certified contractor or one who has passed the EPA’s Radon Contractor Proficiency Program.
Dietary Measures and Lung Cancer
Since damage of DNA by free radicals is considered one of the causes of many types of cancer, researchers hoped that antioxidant supplements or an increased intake of antioxidant-rich foods might reduce the risk of lung cancer. But large studies show that smokers and others at increased risk for lung cancer who take beta-carotene supplements are significantly more likely to develop lung cancer than their counterparts who don't take them.
Currently, no dietary measures are known to reduce the risk of lung cancer. However, a number of agents do show promise and are under investigation in clinical trials.