The Effects of Secondhand Smoke

Medically Reviewed

All the cancer-causing ingredients in tobacco are also found in secondhand smoke.

Secondhand smoke — also called SHS, passive, or involuntary smoking — can increase your risk of heart disease, lung cancer, and other serious illnesses.

According to a 2014 Surgeon General's report, about 2.5 million Americans have died from the effects of secondhand smoke over the past 50 years.

If you're a smoker, the health of a loved one could be a primary motivating factor in your decision to quit smoking.

What Is Secondhand Smoke?

Cigarettes, pipes, and cigars emit two types of secondhand smoke: Sidestream smoke, which is the smoke from the lighted end, and mainstream smoke, the smoke exhaled by a smoker.

Of the two, sidestream smoke is the more dangerous; it contains higher concentrations of carcinogens, is more toxic, and has smaller particles that can penetrate deeper into your lungs than those in mainstream smoke.

What Are the Dangers of Secondhand Smoke?

Secondhand smoke has the same nicotine and harmful chemicals that smokers inhale into their lungs.

It contains more than 7,000 chemical compounds, of which more than 250 are known to be harmful, and at least 69 are known to cause cancer.

In the United States, the costs of extra medical care, illness, and death caused by SHS top $5.6 billion per year, reported a 2010 Surgeon General's report.

Each year, it's responsible for an estimated 46,000 deaths from heart disease and about 3,400 lung cancer deaths in adults who don't smoke.

Children are particularly susceptible to the effects of secondhand smoke. Every year, it causes:

  • Severe asthma and asthma-related problems in up to 1 million asthmatic children
  • Between 150,000 and 300,000 lower respiratory tract infections (bronchitis and pneumonia) in children younger than 18 months
  • Children to be put into intensive care when they have the flu

In addition, there is some evidence suggesting secondhand smoke might be linked to stroke, lymphoma, leukemia, and brain tumors in children.

It's also linked to cancers of the larynx (voice box), pharynx (throat), nasal sinuses, brain, bladder, rectum, stomach, and breast in adults.

Where Is Secondhand Smoke the Biggest Problem?

Secondhand smoke is the most common:

At home: If you're a smoker, the next best thing to quitting that you can do for your family is to keep your home smoke-free.

Spouses, children, and even pets are at risk from the danger of secondhand smoke.

If you live in an apartment building, know that smoke can travel through air ducts and walls, so try to opt for a smoke-free building if at all possible.

At work: Many cities and states have enacted smoke-free work policies, and with good reason: the Surgeon General has said that they are the only way to prevent SHS exposure at work.

In the car: Even if you smoke with the windows rolled down, you are putting your passengers at risk for exposure to secondhand smoke. In fact, some cities and states have laws that ban smoking in the car if you have passengers under a certain age or weight.

In public: More and more public spaces are banning smoking, from parks and restaurants to malls and public transportation.

To date, 28 states and the District of Columbia have passed comprehensive smoke-free laws, including banning smoking in restaurants. Whenever you have a choice, always support a smoke-free business over one that is not.

Editorial Sources and Fact-Checking

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