10 Cancer Myths


Air Pollution or Smoking: Which Is the Greater Risk?

Cancer Myth 6: Living in a polluted city is a greater risk for lung cancer than smoking a pack of cigarettes a day.

Respondents Who Agreed: 40 percent

Origin of Myth: Unknown. This myth appeals to smokers, who are trying to convince themselves that tobacco use isn't all that bad.

Reality: The truth is just the opposite, but more than a third of those questioned in the Discovery Health/Prevention survey agreed with the myth that living in a polluted city is a greater risk for lung cancer than smoking a pack of cigarettes a day.

Air pollution is far less likely to cause lung cancer than smoking cigarettes. Being a smoker, or even being frequently exposed to secondhand smoke is more dangerous than the level of air pollution encountered in U.S. cities.

Dirty air does contribute to lung cancer risk, but has a greater impact on heart disease, asthma and chronic bronchitis. American Cancer Society (ACS) vice president of epidemiology and surveillance Michael Thun, M.D., estimates that air pollution increases the risk of lung cancer by 1/100th of the increased risk brought on by smoking a pack of cigarettes a day.

Most people tend to overestimate the risk caused by factors imposed on them by others and to underestimate the seriousness of risks caused by their own behavior.

Lung cancer was a rare disease at the beginning of the 20th century, when few people smoked. The introduction of manufactured cigarettes, which made them readily available, changed this. About 87 percent of lung cancers are thought to result from smoking or passive exposure to tobacco smoke. Today, lung cancer is the leading cause of cancer death in men and women — expected to cause 157,200 deaths in 2003. The longer you smoke and the more packs per day you smoke, the greater your risk.

If you stop smoking before a cancer develops, your damaged lung tissue gradually starts to return to normal. Ten years after stopping smoking, your risk is reduced to one-third of what it would have been if you continued to smoke. Cigar smoking and pipe smoking are almost as likely to cause lung cancer as cigarette smoking. There is no evidence that smoking low tar cigarettes reduces the risk of lung cancer.

Secondhand Smoke

If you don't smoke, but breathe in the smoke of others (secondhand smoke or environmental tobacco smoke) you are also at increased risk for lung cancer. A nonsmoker who is married to a smoker has a 30 percent greater risk of developing lung cancer than the spouse of a nonsmoker. Workers who have been exposed to tobacco smoke in the workplace are also more likely to get lung cancer.

More effective ways to quit smoking have made headlines in the last year, including free telephone quitlines, which offer personal counseling to find the best mix of medicine and quitting methods for each person.