There is no safe level of exposure for secondhand smoke (SHS), which is also known as environmental tobacco smoke. Passive smoking (inhaling secondhand smoke) happens when non-smokers breathe other people’s tobacco smoke. This includes mainstream smoke (smoke that is exhaled into the air by smokers) and sidestream smoke (smoke that comes directly from the burning tobacco). SHS contains the same harmful chemicals the smokers inhale.

There is strong evidence that SHS causes serious damage to human health. Each year about 3,400 non-smoking adults die of lung cancer and about 46,000 die of heart disease as a result of breathing SHS. There is also some evidence suggesting it may be linked with childhood leukemia and cancers of the larynx (voice box), pharynx (throat), brain, bladder, rectum, stomach, and breast.

SHS can also affect non-smokers by causing asthma and other breathing problems, eye irritation, headaches, nausea, and dizziness.

Children whose parents smoke are more likely to suffer from asthma, pneumonia, bronchitis, ear infections, coughing, wheezing, and increased mucus production. Babies of parents who smoke have a greater chance of dying of sudden infant death syndrome (SIDS). Pregnant women exposed to SHS are at risk for having a low birth weight baby and may also be at risk for pre-term (premature) delivery and miscarriage.

Please see our document called Secondhand Smoke to learn more.

Am I at risk for getting lung cancer from smoke odors on clothing or from being in a room that still smells of tobacco smoke?

There are no medical research reports on the cancer-causing effects of cigarette odors, but research does show that secondhand smoke (SHS) can seep into hair, clothing, dust, and other surfaces. Researchers call this “thirdhand” smoke. This refers to particles that are left on surfaces after you can no longer see the smoke. These particles can become airborne again when disturbed, or they can be picked up by people (especially babies and small children) who touch the surfaces and get particles on their hands and bodies.

Though unknown, the cancer-causing effects would likely be small compared with direct SHS exposure, such as living in a household that has a smoker. But this is an active area of tobacco research.

For more information, see our document called Secondhand Smoke.