Dangers of Smoking that Do Not Just Target the Smoker

Summary: We know that smoking affects the person who actively smokes him- or herself, but what about the people around them? How does secondhand smoke affect the non-smokers?

Many actively choose not to smoke because they understand the risks associated with smoking, but what happens in the case of secondhand smoke? Secondhand smoke, often abbreviated as SHS or labeled as ETS (environmental tobacco smoke)  is a combination of two different forms of smoke that originate from the burning of tobacco:

  • Mainstream smoke – the smoke that is exhaled by a smoker [i]
  • Sidestream smoke – This smokes emanates from the lit end of a cigar, pipe, or cigarette [ii]

While we consider these types of smoke to be the same, they are in fact not. The sidestream smoke contains higher concentrations of carcinogens (cancer-causing agents) than mainstream smoke. In addition, the particles in sidestream smoke are much smaller, which means that they can enter the cells of the body and lungs more easily.

When non-smokers are exposed to secondhand smoke, it is referred to as passive smoking or involuntary smoking. Those non-smokers that breathe in the secondhand smoke still take in the toxic chemicals and nicotine through the same route that active smokers would. This means that the more secondhand smoke someone inhales, the more harmful chemicals this will pump into their body. The fact that dangerous particles that we find in SHS may linger in the air for hours (possibly even longer) also makes it clear that merely opening the window for a few minutes is not going to make a difference.


What is in secondhand smoke?

It would be almost impossible to list all the thousands of toxic chemicals that are included in environmental tobacco smoke. However, some of the most dangerous chemicals include:

  • Carbon monoxide, found in car exhaust
  • Polonium, a radioactive substance
  • Lead, a toxic metal
  • Formaldehyde, an industrial chemical
  • Chromium, used to make steel
  • Cyanide, used in chemical weapons
  • Butane, used in lighter fluid
  • Ammonia, used in cleaning products


Just how risky is it for people around you?

Because the secondhand smoke lingers for a long time and still manages to do damage, it can contribute to or cause a number of serious health problems. These include the following:


  • Heart disease – Secondhand smoke interferes with circulation and damages blood vessels. This increases the odds of a heart attack and heart disease. It may also increase the risks of sudden cardiac death [iii].
  • Lung disease – When a non-smoker is exposed to secondhand smoke, it may aggravate existing respiratory conditions. This is especially true for people with chronic obstructive pulmonary disease or asthma.
  • Cancer – We know that secondhand smoke is a risk factor for lung cancer in non-smokers. It also contains benzene, a chemical that we know can increase the chances of leukemia.

While secondhand smoke is dangerous for healthy adults, children are especially vulnerable to problems with secondhand smoke. This means that secondhand smoke also comes with additional risks for children [iv]. Some of the problems include:

  • Infections – Children who live with someone that actively smokes are more likely to develop middle ear infections, pneumonia, and bronchitis.
  • Overall irritations – Secondhand smoke can also cause eye and nose irritation, increased wheezing, increased phlegm, and chronic coughing.
  • Asthma – Being exposed to secondhand smoke may increase the severity or risk at developing childhood asthma.
  • Sudden infant death syndrome – Secondhand smoke increases the risk of sudden infant death syndrome.
  • Low birth weight – If the fetus is exposed to secondhand smoke, it increases the odds that the fetus is born with low birth weight.

It affects so many people with so many different problems

By now, it should be obvious that secondhand smoke can harm people in numerous ways. In just the United States, secondhand smoke is responsible for the following:

  • Almost 46,000 deaths due to heart disease in people who are not active smokers
  • Almost 3,400 lung cancer deaths in adults who are not active smokers
  • Worsening asthma-related problems and asthma for upwards of 1 million asthmatic children
  • Between 150,000 and 300,000 lung and bronchus infections for children younger than 18 months. These lower respiratory tract infections lead to 7,500 to 15,000 hospitalizations every year
  • When children are around secondhand smoke they are more likely to need breathing tubes, be in the hospital longer, and are more likely to be placed into intensive care when they have problems with the flu.
  • The cost in the United States alone for additional deaths, illnesses, and medical care each year as caused by secondhand smoke totals more than $10 billion per year.

It should be obvious that secondhand smoke is far more dangerous than previously believed. The importance of avoiding secondhand smoke altogether cannot possibly be overstated. Because the dangers can linger for hours after the smoker has removed him- or herself from the area, it is important to avoid being around active smokers altogether.


[i] Chepiga, T. A., Morton, M. J., Murphy, P. A., Avalos, J. T., Bombick, B. R., Doolittle, D. J., … & Swauger, J. E. (2000). A comparison of the mainstream smoke chemistry and mutagenicity of a representative sample of the US cigarette market with two Kentucky reference cigarettes (K1R4F and K1R5F).Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association38(10), 949.

[ii] Pryor, W. A., Prier, D. G., & Church, D. F. (1983). Electron-spin resonance study of mainstream and sidestream cigarette smoke: nature of the free radicals in gas-phase smoke and in cigarette tar. Environmental health perspectives47, 345.

[iii] Pechacek, T. F., & Babb, S. (2004). How acute and reversible are the cardiovascular risks of secondhand smoke?. Bmj328(7446), 980-983.

[iv] Wipfli, H., Avila-Tang, E., Navas-Acien, A., Kim, S., Onicescu, G., Yuan, J., … & Samet, J. M. (2008). Secondhand smoke exposure among women and children: evidence from 31 countries. Journal Information98(4).