Call your local emergency number or go to an emergency room if a child around secondhand smoke has trouble breathing, is wheezing badly, has bluish lips or skin, is unusually limp or hard to wake, or has a high fever with fast or labored breathing. These signs need medical attention immediately — this article is not a substitute for that care.
How Secondhand Smoke Affects Children
Secondhand smoke raises a child’s risk of sudden infant death syndrome (SIDS), ear infections, respiratory infections like pneumonia and bronchitis, and more frequent, more severe asthma attacks. Children are especially vulnerable because their bodies, airways, and lungs are still growing and developing, according to the U.S. Environmental Protection Agency (EPA).
Secondhand smoke is smoke released from burning tobacco products such as cigarettes, cigars, hookahs, or pipes. It contains more than 7,000 chemicals, including about 70 that can cause cancer, according to the Centers for Disease Control and Prevention (CDC). The CDC states there is no safe level of secondhand smoke exposure — even brief exposure can cause health problems.
Respiratory Infections and Slowed Lung Growth
Children exposed to secondhand smoke have an increased risk of acute respiratory infections, including pneumonia and bronchitis, according to the CDC. They may also experience more frequent and severe respiratory symptoms, such as wheezing, coughing, and shortness of breath, along with slowed lung growth.
Asthma Attacks
Children who already have asthma and are around secondhand smoke have more severe and more frequent asthma attacks, the CDC reports. In some cases, these attacks can become dangerous enough to threaten a child’s life. Keeping a child with asthma away from secondhand smoke is one of the most direct ways to reduce attack frequency and severity.
Ear Infections
Children whose parents or caregivers smoke around them get more ear infections. They are also more likely to have fluid buildup in the middle ear and to need surgery to place ear tubes for drainage, according to the CDC.
SIDS Risk
Infants exposed to secondhand smoke after birth are more likely to die from sudden infant death syndrome, according to the CDC. Researchers believe the chemicals in secondhand smoke may affect the parts of an infant’s brain that regulate breathing. Infants who die of SIDS and were exposed to secondhand smoke tend to show higher nicotine and cotinine (a nicotine byproduct) levels than infants who died of other causes.
Why Children Are More at Risk Than Adults
The EPA notes that secondhand smoke affects everyone, but children are especially vulnerable because they are still growing and developing. Their airways, lungs, and immune systems are not yet fully mature, which is part of why exposure during childhood is linked to a wider range of health problems than exposure in adulthood.
Extra-Caution Groups
Some children face higher stakes from secondhand smoke exposure than others:
- Infants under one year old, because of the link to SIDS.
- Children with asthma or other chronic respiratory conditions, because attacks can become severe quickly.
- Children in homes where multiple people smoke, or where smoking happens indoors or in the car, because exposure is harder to avoid.
- Children in multi-unit housing, where smoke can drift between units through shared walls, vents, or hallways, per the CDC.
Protective Measures Checklist
The CDC and EPA agree that completely eliminating smoking indoors and in vehicles is the only way to fully protect children from secondhand smoke. Use this checklist as a starting point:
- Make your home and car 100% smoke-free and vape-free, including for guests.
- Never smoke or vape near an entryway, window, or air intake to an enclosed space — smoke can still drift inside.
- Ask caregivers, family members, and anyone who cares for your child not to smoke around them, in any location.
- Choose smoke-free child care settings and vehicles when possible.
- Understand that opening a window, using a fan, or running an air purifier reduces but does not eliminate exposure, according to the EPA.
- If you smoke, consider talking with a healthcare provider about quitting — it’s the most effective way to protect your child from ongoing exposure. Our evidence-based starter guide to quitting smoking covers where to begin.
Ventilation and Air Cleaners Are Not Enough
Many families assume that opening a window or running an air purifier solves the problem. It doesn’t. The EPA is clear that ventilation, filtration, and air cleaning can reduce secondhand smoke levels but will not eliminate the harmful chemicals. For a closer look at why these methods fall short and what actually works, see our guide on why ventilation and air cleaners are not enough at home.
Thirdhand Smoke: The Part Many Parents Miss
Secondhand smoke chemicals don’t just disappear when a cigarette is put out. They settle onto surfaces like walls, furniture, carpets, and car interiors, and can re-enter the air or transfer to skin through touch — this residue is known as thirdhand smoke, according to the EPA. This matters for crawling infants and young children who spend time on floors, furniture, and car seats where residue can build up over time. Our detailed article on secondhand and thirdhand smoke exposure risks and evidence covers the research behind this in more depth.
Building a Smoke-Free Home Environment
Protecting a child from secondhand and thirdhand smoke fits into the larger picture of indoor air quality. If you’re working on other steps to improve the air your family breathes at home, our indoor air quality guide for protecting your lungs at home offers additional practical steps.
Secondhand Smoke Risks at a Glance
- SIDS: higher risk in infants exposed to secondhand smoke after birth.
- Ear infections: more frequent infections, more fluid buildup, and more ear tube surgeries.
- Asthma: more frequent and more severe attacks in children who already have asthma.
- Respiratory infections: higher risk of pneumonia and bronchitis.
- Lung development: slowed lung growth and more respiratory symptoms.
Evidence Limits
This article summarizes findings from the CDC and EPA, which draw on decades of public health research. Research in this area generally looks at population-level patterns rather than predicting outcomes for any individual child. Not every child exposed to secondhand smoke will develop these problems, and other factors — such as overall health, genetics, and the amount and length of exposure — also play a role. If you have questions about your child’s specific health or exposure history, a pediatrician or family doctor can give guidance based on your child’s situation.
Frequently Asked Questions
Is there a safe amount of secondhand smoke for children?
No. The CDC states there is no safe level of secondhand smoke exposure, and even brief exposure can cause health problems.
Does vaping around my child carry the same risks as smoking?
Vaping emissions are not the same as cigarette smoke, but health agencies including the CDC recommend including e-cigarettes in smoke-free policies because they release harmful substances into the air. If you have questions about vaping specifically around children, a healthcare provider can offer guidance based on current research.
Can an air purifier protect my child if someone smokes in the house?
Air purifiers and ventilation can reduce secondhand smoke levels in the air, but the EPA states they will not eliminate the harmful chemicals. The only way to fully protect a child is to keep the home and car completely smoke-free.
What is thirdhand smoke, and can it affect my child even if no one smokes around them directly?
Thirdhand smoke is the residue that settles on surfaces like walls, furniture, and car seats after smoking, and it can re-enter the air or transfer through touch, per the EPA. This means a child can be exposed even if smoking only happened in the past or in another room.
Educational Disclaimer
This article is for general educational purposes only. It is not medical advice and does not diagnose any condition, predict individual outcomes, or replace care from a qualified healthcare provider. If you have concerns about a child’s breathing, health, or exposure to smoke, talk with a pediatrician or other qualified clinician.