Exposure

• Secondhand smoke may come in the form of exhalations from cigarette smokers, cigar smokers or pipe smokers, but it may also come from the smoke that wafts from the end of a burning cigarette, pipe or cigar. In buildings where smoking is allowed and the air is recirculated through a venting system, nonsmokers are exposed to ETS in elevated levels.
  
  

Risk

• The CDC reports that adult nonsmokers who are exposed regularly to secondhand smoke are up to 30 percent more likely to develop lung cancer as a result of inhaling the passive smoke. As many as 3,000 adults die from lung cancer every year as a result of exposure to secondhand smoke.
  
  

Time Frame

• The longer a person is exposed to passive smoke, the greater the risk that he will develop lung cancer or another respiratory disorder. Secondhand smoke damages cells in the lungs, and the U.S. Department of Health and Human Services advises that there is no safe level of exposure to passive smoke.
  
  

Effects

• Recent publications explain the dangers of inhaling secondhand smoke and the increased risk of developing lung cancer. According to a 2006 report from the U.S. surgeon general, nonsmokers may inhale more cancer-causing chemicals than do smokers since the carcinogenic toxins from the burning end of a cigarette are highly concentrated and more dangerous than the smoke inhaled through the cigarette itself.
  
  

Dangers to Children

• When children inhale secondhand smoke, their risk of developing lung cancer is higher when they become adults, but it is slightly less than adults who are exposed for the same amount of time to ETS. This discrepancy may be due to the increased healing rate of lung tissue in children, according to a study published in 1999 in the "International Journal of Cancer." However, adults who were exposed to secondhand smoke as children and also during their adult years have the highest risk of lung cancer in all groups of nonsmoking patients exposed to ETS.
  
  

Prevention

• Communities are increasingly passing legislation to ban smoking in public places, restaurants, workplaces and bars in an attempt to reduce the risk from secondhand smoke. Parents who smoke should do so outdoors, and smoking in a vehicle while others are present is not advisable. Resources to make smokers aware of the risk from ETS and to assist them in kicking the habit are available in most communities and online (see Resources).