Is the smell of cigarettes the same as secondhand smoke?

July 21, 2009 -Harvard Medical School - HEALTHbeat..

Q: A family friend just started smoking again. He doesn’t smoke while my young daughter and I are there, but his house is saturated with the smell. Is this secondhand smoke? Should I be concerned?

A. Secondhand smoke (passive smoking, involuntary smoking, environmental tobacco smoking, ETS, SDS) is defined as the combination of sidestream smoke, which comes from the burning end of a cigarette, and mainstream smoke, which is smoke exhaled by the smoker. While the smell of smoke doesn’t necessarily correlate with the amount of secondhand smoke in a room, you and your daughter are being exposed to some level of smoke toxins.

There are good reasons to avoid secondhand smoke. It increases the risk of lung cancer, heart disease, chronic respiratory problems, and possibly cancers of the cervix, breast, and bladder. In children, it’s been linked to middle ear infections, bronchitis, and asthma. Exposure in the womb is associated with low birth weight and sudden infant death syndrome.

More than 250 chemicals in secondhand smoke are known to be toxic or carcinogenic. They can linger in the air as gases or particles and may be absorbed through the nose, mouth, or skin. Some become carcinogenic only after they’re activated by enzymes in the body and become part of a cell’s DNA.

In June 2006, the Surgeon General issued a report, The Health Consequences of Involuntary Exposure to Tobacco Smoke, which concluded that there is no safe level of secondhand smoke exposure. It also stated that cleaning the air or ventilating buildings cannot completely eliminate secondhand smoke exposure. Banning smoking in indoor spaces is the only way to fully protect nonsmokers.

You and your daughter probably get very little exposure to secondhand smoke when you visit your friend, but your visits are not risk-free. The safest route is to have him visit in your home, with the understanding that he’ll go outside if he wants to smoke. Of course, whatever you can do to encourage him to stop smoking will be good for everyone.
— Celeste Robb-Nicholson, M.D.
Editor in Chief, Harvard Women’s Health Watch

This Question and Answer first appeared in the October 2006 Harvard Women’s Health Watch, available at

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