Because smoking is tied so strongly to lung cancer, not smoking is naturally the most effective preventive method. People who smoke, however, can reduce their risk by quitting. Research has shown that the beneficial effects of quitting smoking increase the longer a former smoker does not smoke.

For instance, a study had found that after five years of abstinence from cigarettes, former smokers had 16 times the risk of developing cancer. But that risk was reduced to 8 percent after the next five years and gradually declined to 2 percent over the next 30 years.

Avoiding passive smoke is another prevention method. Smoke-free restaurants, hotels and workplaces help in avoiding unwanted smoke. Requesting that smokers do so outdoors when in the home, car or workplace also helps.

People should be aware of potential occupational and environmental toxins. Radon, asbestos, nickel, chromate, diesel smoke and vinyl chloride should be avoided because they increase risk of lung cancer.

Finally, studies are beginning to show how diet relates to cancer risk. Researchers are finding that diets high in antioxidants (contained in fruits and vegetables) appear to offer some protection against cancers.