Second Hand Smoke

Secondhand smoke is a mixture of the smoke coming off of the burning end of a cigarette, cigar, or pipe (side stream smoke) and the smoke exhaled by the smoker (main stream smoke).

Burning tobacco puts thousands of chemicals into the air. Because side stream smoke is generated at lower temperatures and under different conditions than main stream smoke, it contains higher concentrations of many of the toxins found in inhaled cigarette smoke. It is involuntarily inhaled by nonsmokers, lingers in the air hours after cigarettes have been extinguished and can cause or exacerbate a wide range of adverse health effects, including cancer, respiratory infections, and asthma.

Secondhand smoke contains over 4,000 chemicals and hundreds of the chemicals are known to be toxic or carcinogenic- causing cancer. The Surgeon General's Report concluded that scientific evidence shows there is no risk-free level of exposure to secondhand smoke.

Second Hand Smoke Harms Everyone


Adults who breathe secondhand smoke can suffer from:

  • Heart disease
  • Lung cancer
  • Stroke

In the U.S, secondhand smoke causes almost 50,000 deaths in adult non-smokers each year, including approximately 3,400 from lung cancer and 23,000 to 69,000 from heart disease.

Non-smoking spouses married to smokers have a 20% increased risk of lung cancer compared with those whose spouses don't smoke.

Secondhand smoke is the third leading cause of preventable death in Montana.


Children who breathe secondhand smoke are more likely to experience the following:

  • Bronchitis and Pneumonia and other lung disease
  • An increased chance of developing asthma
  • More frequent asthma attacks
  • More frequent ear infections
  • Sudden Infant Death Syndrome (SIDS)
  • Wheezing and coughing

Children's bodies are not fully grown, so they have an even harder time fighting the harmful effects of second hand smoke.

Secondhand smoke is responsible for between 150,000 and 300,000 lower respiratory tract infections in infants and children under 18 months of age, resulting in between 7,500 and 15,000 hospitalizations each year, and causes 430 SIDS deaths in the United States annually.

Secondhand smoke causes between 8,000 and 26,000 new cases of childhood asthma a year.

Protect Your Family & Friends

If you smoke:

  • Never smoke around children or pregnant women.
  • Smoke outside, away from doors and windows.
  • Be courteous. If someone asks you not to smoke around them, comply with their request. They are only trying to protect their own health.

Protect Yourself

  • Ask others not to smoke in your home or car.
  • Let family, friends and people you work with know that you do care if they smoke around you.
  • Educate your family and neighbors about the dangers of secondhand smoke.
  • Choose to eat at non-smoking restaurants
  • Ask for a smoke free work area.
  • Make sure your child's day-care, school and after-school programs are smoke-free.

23 states, including Montana, have passed laws prohibiting smoking in almost all public places and workplaces, including restaurants and bars.

Pregnancy & Smoking

Smoking is especially harmful to pregnant women. Smoking during pregnancy can harm the health of both a woman and her unborn baby. Currently, at least 10% of women in the U.S. smoke during pregnancy. Smoking can be associated with a number of pregnancy complications.

Pregnant women who smoke are more likely to have:

  • Babies with slow physical growth and mental development
  • Birth Defects
  • Low-birth-weight babies (small babies are more likely to have health problems)
  • Miscarriages
  • Premature babies
  • Stillbirths

If you quit smoking, you and your baby can enjoy these benefits:

  • Fewer upper respiratory infections
  • Healthier breast milk
  • Less chance of allergies
  • Less risk of SIDS