Secondhand Smoke and Lung Cancer

How Often Does Secondhand Smoke Cause Lung Cancer?

young boy holding a no smoking sign
What is the relationship of secondhand smoke and lung cancer?.

Secondhand Smoke and Lung Cancer

The link between secondhand smoke and lung cancer has received a lot of attention lately. Laws now prohibit smoking in many public places, and TV commercials yank at our heartstrings as they depict someone that smoked mourning the loss of a non-smoking loved one. What are the facts?

Definition of Secondhand Smoke

First, what is secondhand smoke? Secondhand smoke (or environmental tobacco smoke (ETS) refers to the exposure to smoke from cigarettes another person is smoking.

It is also called passive smoking or involuntary smoking. Secondhand smoke is made up of two components. “Sidestream smoke” is the smoke that is present in air from the end of a burning cigarette. “Mainstream smoke” is smoke that is exhaled by someone who is smoking after it has traveled through the lungs. Research on animals suggests that sidestream smoke may be even more dangerous than mainstream smoke, but regardless of the debate, secondhand smoke is a known human carcinogen (cancer-causing substance).

The Statistics about Secondhand Smoke and Lung Cancer

Secondhand smoke alone is responsible for roughly 7,000 lung cancer deaths each year in the United States and over 21,000 lung cancer deaths worldwide. Living with a smoker increases an individual’s chance of developing lung cancer by 20 to 30 percent.

According to U.S. Surgeon General’s report in 2006, even brief secondhand smoke exposure can cause the damage that can lead to lung cancer.

Despite this risk, the report also found that nearly half of non-smoking individuals are regularly exposed to secondhand smoke. The best ventilation systems are unable to filter out secondhand smoke completely, and only smoke-free establishments are risk-free.

The Culprits - Carcinogens in Tobacco Smoke Which Cause Cancer

There are more than 50 chemicals in tobacco smoke that are known to cause cancer.

Some of the better-known carcinogens include arsenic, benzene, nickel, and vinyl chloride. The following articles discuss this in greater depth:

How Can You Protect Yourself?

Since no level of secondhand smoke exposure is safe, insisting on a no-smoking policy in your home is an important first step in protecting yourself. Choosing public establishments, such as restaurants, that are smoke-free is helpful as well, although the availability may depend on the laws where you live. If you travel, avoiding secondhand smoke can be more difficult.  Here are some ways to avoid secondhand smoke when traveling.

Secondhand Smoke and People Living With Lung Cancer

For someone living with lung cancer, secondhand smoke exposure can carry a double-edged sword. As an irritant to the lungs, secondhand smoke can worsen symptoms that are already present, such as coughing, but can be painful from an emotional standpoint as well. Studies tell us that lung cancer survivors experience significant distress when family members continue to smoke.

If you have lung cancer and smoke, check out these 10 important reasons to quit smoking with cancer.

 If you smoke and your loved one has cancer, this may be a good time to quit - but you need to do this for yourself.  You are worth it!


American Cancer Society. Secondhand Smoke. 11/13/15.

Besaratinia, A. and G. Pfeifer. Second-hand smoke and human lung cancer. The Lancet Oncology. 2008. 9(7):657-666.

National Cancer Institute. Secondhand Smoke and Cancer. Updated 01/12/11.

Oberg, M. et al. Worldwide burden of disease from exposure to second-hand smoke: a retrospective analysis of data from 192 countries. Lancet. 2011. 377(9760):139-46.

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