No amount of secondhand smoke is safe - at any age, according to the U.S. Surgeon General. But exposure to secondhand smoke is especially unsafe for infants and young children because their bodies and lungs are still developing. Yet almost 60% of U.S. children between ages 3 and 11 are exposed to secondhand smoke, the U.S. Surgeon General reported in 2006.

To raise awareness of the dangers of secondhand smoke, the American Society of Clinical Oncology (ASCO) is working with the International Union Against Cancer to promote World Cancer Day on February 4, 2008. The theme is “I love my smoke-free childhood.”

What is secondhand smoke?

Secondhand smoke is when you breathe a smoker's exhaled smoke plus the smoke from their lit cigarette, cigar, or pipe. Other names for it are passive smoking and involuntary smoking. Inhaling another person's smoke is like smoking. Many of the harmful substances in tobacco stay in the air and go into your lungs and bloodstream. Secondhand smoke is a poisonous cocktail that includes lead, carbon monoxide, arsenic, ammonia, formaldehyde, and a type of cyanide. Cigars create larger amounts of secondhand smoke than cigarettes because they contain more tobacco than cigarettes and burn longer, according to the National Cancer Institute.

Health risks to children of secondhand smoke

Much research shows that secondhand smoke increases children's risk of certain health problems. Compared with children who are not around tobacco smoke, they more often develop:

• Ear infections
  
  
• More severe asthma
  
  
• Lung infections, such as bronchitis and pneumonia
  
  
• Coughing and wheezing without a cold
  
  
• A tonsillectomy (an operation to remove the tonsils)
  
  
• Dental cavities

Children of smokers miss more days of school than children who are not around smoke, according to the American Cancer Society. Secondhand smoke also may hurt children's ability to learn. One large study of children 6 to 16 years old found lower test scores in children who were around tobacco smoke, compared with kids who were not. This result held true even at low levels of exposure.

Doctors have long known that smoking during pregnancy hurts the baby and raises the risk of sudden infant death syndrome (SIDS). More recently, a few public health reports stated that secondhand smoke after birth is a risk factor for SIDS, even if the mother did not smoke while pregnant. More research is needed in this area.

Secondhand smoke in childhood also may have long-term health risks. A recent study showed that in children as young as 11, secondhand smoke can hurt the function of the heart's arteries, just as it does in adults. A study in 2005 found that overweight teens were four and a half times more likely to have metabolic syndrome if they breathed secondhand smoke than those who did not. Metabolic syndrome is the name for a group of risk factors (such as high blood pressure) for heart disease and diabetes.

And in adults who don't smoke, secondhand smoke is known to cause lung cancer and heart disease.

Make sure your children don't breathe secondhand smoke

When someone smokes inside, it is not enough to keep the smoke away by opening a window or using a fan. The only way to fully protect children from secondhand smoke, according to the U.S. Surgeon General, is to get rid of smoking indoors. For that reason, many states have banned smoking in restaurants and other public buildings.

Here are ways you can protect your family from secondhand smoke.

• Keep your home and car smoke-free.
  
  
• Make sure the places where your child spends time, such as day care, school, or after-school programs, do not allow smoking. If they do, smoking should be either in a room that children do not need to go into, or outside, away from the doors.
  
  
• Ask caregivers and relatives not to smoke around your kids.
  
  
• Eat in restaurants that are smoke-free. Non-smoking sections do not protect from secondhand smoke.
  
  
• If you are pregnant, avoid being around smoking.
  
  
• If you smoke, quit. For more information on quitting smoking, read the Cancer.Net Feature: Resources to Help You Quit Smoking.

Keeping your children away from smoking may have an added benefit. A study in 2004 showed that children of smokers are less likely to start smoking by 12th grade if their parents routinely sit in smoke-free areas of public places. Not smoking in the home also helped prevent teen smoking, the study found.

Additional Resources

Centers for Disease Control and Prevention: Secondhand Smoke

U.S. Surgeon General: The Health Consequences of Involuntary Exposure to Tobacco Smoke

U.S. Environmental Protection Agency: Smoke-free Homes Program

More Information

ASCO Expert Corner: World Cancer Day 2008

Tobacco

Best Defense Against Many Cancers: Preventing Tobacco Use by Children and Teens