Secondhand smoke is a dangerous and usually avoidable Indoor Air Quality problem. Secondhand smoke, also known as environmental tobacco smoke, includes smoke that has been exhaled by a smoker (mainstream smoke) as well as smoke that enters the air directly from a burning cigarette, cigar or pipe (known as sidestream smoke). Sidestream smoke is considered the most dangerous form of secondhand smoke, because it contains the highest concentration of toxic compounds.

There are as many as 7,000 chemicals in secondhand smoke, hundreds of which are toxic, including hydrogen cyanide, carbon monoxide and ammonia. At least 69 chemicals in secondhand smoke are known to cause cancer, according to the National Cancer Institute. These include arsenic, benzene and Polonium-210, a radioactive chemical element.

Health effects of secondhand smoke

The results of breathing secondhand smoke are distressing. Every year, secondhand smoke causes more than 3,000 American deaths from lung cancer and more than 46,000 deaths from heart disease. As many as 300,000 children under 18 months of age are diagnosed with lower respiratory tract infections in the U.S. every year as a result of secondhand smoke.

Secondhand smoke is also linked to childhood leukemia and cancers of the voice box, throat, brain, bladder, rectum, stomach and breast. It causes bronchitis and pneumonia. Secondhand smoke triggers asthma episodes and increases the severity of asthma symptoms, especially among children. A study published in 2013 by the Centers for Disease Control and Prevention showed an association between children’s exposure to secondhand smoke and missing school, health care visits and activity limitations due to wheezing, even at very low exposure levels.

No safe level of exposure

Secondhand smoke particles linger in the indoor air for up to four hours, according to the Cleveland Clinic. Research at Cornell University showed that even at the lowest possible levels of detectable exposure to secondhand smoke, genetic damage occurs within the cells that line the respiratory system’s airways. Damage to these cells leads to chronic obstructive pulmonary disease (COPD) and bronchogenic cancer. The U.S. Surgeon General and the American Cancer Society agree that there is no risk-free level of exposure to secondhand smoke.

Strategies to deal with secondhand smoke

Studies have demonstrated that a HEPA air purifier can reduce the frequency and severity of asthma symptoms associated with secondhand smoke. In cases where indoor smoking cannot be eliminated, a high-performance air purifier such as the IQAir GC MultiGas is recommended because it helps control gaseous chemicals as well as particles.

The most effective strategy to eliminate the dangers of secondhand smoke is to completely eliminate smoking within the home. The American Lung Association offers this advice: Establish a smoke-free policy in your home, and never allow anyone to smoke indoors at any time.