Secondhand smoke is also known as Environmental Tobacco Smoke which includes both exhaled mainstream smoke from smokers and sidestream smoke from the end of a cigarette, cigar, or pipe. Secondhand smoke contains more than 4,000 substances, including over 40 that are linked to cancer. Many of the compounds in tobacco smoke are released at higher rates in sidestream smoke than in mainstream smoke.

How Does Secondhand Smoke Relate To Asthma?

Secondhand smoke may trigger asthma episodes and make asthma symptoms more severe in children who already have asthma. Moreover, secondhand smoke is a risk factor for new cases of asthma in children who have not previously exhibited asthma symptoms.

The means by which secondhand smoke triggers an asthma episode is believed to be through its irritancy effects - it irritates the chronically inflamed bronchial passages of asthmatics. This is a different pathway from most of the other environmental triggers of asthma, like dust mites and pet dander, which trigger asthma episodes through allergenic effects.

Exposure to secondhand smoke is also known to cause a variety of other negative health consequences, including lung cancer, ear infections in children, and respiratory illnesses.

Many of the health effects of secondhand smoke (including asthma) are most clearly manifested in children. This is because children are particularly vulnerable to secondhand smoke. This is likely due to several factors, including the fact that children are still developing physically, have higher breathing rates than adults, and have little control over their indoor environments. Children receiving high doses of secondhand smoke, such as those with smoking mothers, run the greatest relative risk of experiencing damaging health effects.

Air Cleaning - The three most common approaches for reducing the effects of secondhand smoke and indoor air pollution are:

Source Control: The first approach to combating indoor air pollution involves minimizing the use of products and materials that cause indoor pollution, employing good hygiene practices to minimize biological contaminants (including the control of humidity and moisture, and occasional cleaning and disinfection of wet or moist surfaces), and using good housekeeping practices to control particles. Eliminate or control the sources of pollution; although it is difficult to force pets outdoors, stop smokers and eliminate all odors.

Ventilation: The second approach which employs outdoor air ventilation, is also effective and commonly employed. Ventilation methods include installing an exhaust fan close to the source of contaminants, increasing outdoor air flows in mechanical ventilation systems, and opening windows, especially when pollutant sources are in use. Dilute and exhaust pollutants through outdoor air ventilation; in the winter however, venting to the outdoors may increase heating and energy costs.

Air Cleaning:  The third approach supplements source control and ventilation. Air filters, electronic particle air cleaners and ionizers are often used to remove airborne particles, and gas adsorbing material is sometimes used to remove gaseous contaminants when source control and ventilation are inadequate. Remove pollutants through proven air cleaning methods and products.