How Secondhand Smoke Hurts Children

Men smoking in car
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Secondhand smoke, or environmental tobacco smoke (ETS), is particularly harmful to children and can increase their risk of multiple health issues.

ETS is made up of a combination of exhaled cigarette smoke (mainstream smoke) and smoke that comes from the end of a smoldering cigarette (sidestream smoke). It is also be referred to passive smoke and involuntary smoke.

Secondhand smoke is a nasty mixture of more than 7,000 chemicals, 250 of which have been identified as poisonous and about 70 that are carcinogenic. According to the 2006 report of the Surgeon General, The Health Consequences of Involuntary Exposure to Tobacco Smoke, there is no safe level of exposure to secondhand smoke.

Increased Risks for Children

On average, children have more exposure to secondhand smoke than non-smoking adults. Cotinine levels in children between 3 and 11 years old are more than double that of non-smoking adults.

What Is Cotinine?

Cotinine is the substance created in the body from nicotine and can be used to measure someone's exposure to secondhand smoke.

One reason for this finding is that young children have little control over their surroundings. About half of American middle and high school students breathe in secondhand smoke in cars, homes, and public places where smoking is allowed, according to data from 2013 published in the journal Pediatrics.

Even children who live in non-smoking households may be exposed to secondhand smoke at home. A 2011 study found that children who live in non-smoking homes that are in multi-family dwellings (apartments, condos) have approximately 45% higher cotinine levels than children who live in non-smoking single-family homes.

Children also face a greater risk than adults of the negative effects of secondhand smoke, in part because children's lungs are still developing.

Additionally, when the air is tainted with cigarette smoke, young, developing lungs receive a higher concentration of inhaled toxins because a child's breathing rate is faster than an adult's. Adults breathe in and out approximately 14 to 18 times a minute, while newborns can breathe as many as 60 times a minute. Up until a child is about 5 years old, their respiratory rate is quite fast.

Scientists have uncovered numerous risks associated with secondhand smoke for young children, and the research continues. To date, there are plenty of sobering facts about how this toxic air damages children's health.

Impact During Pregnancy

Secondhand smoke can negatively affect babies as they develop during pregnancy. If a pregnant person smokes during pregnancy, the baby is at an increased risk for developmental issues such as learning disabilities and cerebral palsy and having a low birth weight or being small for gestational age. Low birth weight is a leading cause of infant death.

Similarly, for pregnant people who don't smoke themselves, exposure to secondhand smoke during pregnancy can present risks for the baby as well.

Impact on Children's Health

The lungs of children who regularly breathe in secondhand smoke develop more slowly. The impact of secondhand smoke on children also includes increased risks of health conditions.

Sudden Infant Death Syndrome (SIDS)

Babies who are exposed to secondhand smoke are at a higher risk for SIDS, which is when a child younger than 12 months old dies suddenly and unexpectedly. Smoking during pregnancy also increases the risk of SIDS.

Middle Ear Disease

A 2012 meta-analysis published in Archives of Pediatric and Adolescent Medicine found that children exposed to secondhand smoke had a significantly higher risk of developing middle ear disease.

Inhaled cigarette smoke irritates the eustachian tube, the pathway that connects the throat and middle ear. The resulting inflammation (known as otitis media) is the most common cause of hearing loss in young children.


Secondhand smoke creates problems for children with asthma and can exacerbate and make breathing issues more frequent. Passive smoking may also be responsible for new cases of asthma.

Lower Respiratory Tract Infections

According to a 1992 report from the Environmental Protection Agency (EPA), among children under 18 months of age in the United States, secondhand smoke is associated with 150,000 to 300,000 cases of lower respiratory tract infections, such as bronchitis or pneumonia, each year.

Research has also uncovered evidence that suggests secondhand smoke may be related to childhood leukemia, lymphoma, and brain tumors. However, to date, that evidence is insufficient to link these childhood cancers with secondhand smoke definitively.

Thirdhand Smoke

In addition to secondhand smoke, children who regularly spend time in places where people smoke are also exposed to thirdhand smoke, also referred to as residual tobacco smoke. Thirdhand smoke is formed when toxic particulate matter in cigarette smoke settles on surfaces and stays put, along with the residue from gases in cigarette smoke.

Thirdhand smoke isn't healthy for anyone, but it's of particular concern for small children who crawl on their hands and knees and touch toys with their fingers that then go into their mouths.

Minimizing the Risks

The only way to fully protect children from secondhand smoke is to quit smoking if you smoke and to keep your child away from people who smoke and places where people regularly smoke. If you smoke and aren't ready to quit, do your best to minimize your child's exposure to secondhand or thirdhand smoke by:

  • Don't smoke inside your home, and don't let anyone else either. Opening windows or using air filters is not enough to protect people from secondhand and thirdhand smoke in an enclosed space.
  • Don't smoke in your car. Even if your kids aren't with you, remember that toxins settle on surfaces, and they'll be exposed to them.
  • Avoid any indoor spaces (restaurants, sporting events, friends' houses where smoking occurs, etc.) where your kids will be exposed to secondhand smoke.
  • Get some distance between you and people who are smoking in outdoor spaces. Yes, outdoor air dilutes cigarette smoke, but if the wind is blowing in your direction you and your children could still breathe in toxic air.

A Word From Verywell

With around 70 carcinogenic and 250 poisonous known chemical components, it is clear that air laden with secondhand smoke is toxic and unsafe for anyone, especially children. It is up to adults to provide children with healthy air to breathe.

If you smoke, make sure that you do all that you can to protect others from the secondhand smoke you create. Better yet, get started on your quit journey. It's never too late to stop smoking, and the work it takes to achieve is minor when compared to the benefits you'll enjoy once you do.

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21 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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