Secondhand Smoke: Why No Level of Exposure Is Safe

At a glance

• Secondhand smoke — smoke from burning cigarettes, cigars, hookahs or pipes, and the smoke people breathe out — causes disease and early death in people who don't smoke.
• There is no safe level of exposure; even brief exposure can do immediate, serious harm.
• Only eliminating smoking indoors fully protects nonsmokers. Comprehensive smokefree laws ban smoking in all workplaces and public places, including restaurants and bars.

What's in it

Commercial tobacco smoke contains more than 7,000 chemicals — hundreds of them toxic, and about 70 that can cause cancer.

A few of the chemicals and toxins in commercial tobacco smoke. CDC.

The harm

Adults who don't smoke can get coronary heart disease, stroke and lung cancer from secondhand smoke.

Infants and children are hit especially hard because their bodies are still growing. They face higher risks of:

• sudden infant death syndrome (SIDS);
• acute respiratory infections such as pneumonia and bronchitis;
• middle ear disease;
• more frequent and severe asthma;
• respiratory symptoms;
• slowed lung growth.

Where people are exposed

Mostly at home and at work — and in public places such as bars, restaurants and casinos. People in multi-unit housing such as apartment buildings are more likely to be exposed: even if nobody in their home smokes, smoke drifts in from other units through hallways, stairwells and ventilation.

Protection

The harm is preventable.

• Comprehensive smokefree laws and policies covering all indoor areas are the only way to fully protect nonsmokers. They also help people quit and keep young people from starting.
• They must be applied equitably, so everyone has a fair chance to breathe smokefree air.
• Most also ban e-cigarettes, whose aerosol can contain harmful substances. Including e-cigarettes protects nonusers and helps change social norms around tobacco. More on e-cigarettes.

Sources

Based on "About Secondhand Smoke," Office on Smoking and Health, Centers for Disease Control and Prevention; a work of the United States government in the public domain.