We proved and know for a fact that smoking is dangerous for your health. The chemicals from burning tobacco products like cigarettes, cigars, and pipes can cause numerous medical conditions. But did you know that the smoke you inhale from another person, even if you yourself do not smoke, can also be dangerous? This is known as secondhand smoke and it is steadily becoming an alarming public health hazard. Read on to learn more about secondhand smoke and how you can lessen your exposure to these harmful substances. 

What Is Secondhand or Passive Smoking?

Second-hand smoking is when someone breathes in the gases and particulates mixture from another person burning tobacco products, like cigarettes, cigars, or hookahs, and is not smoking themselves¹. This smoke contains harmful chemicals and toxins that can cause cancer, even for those not smoking. Here are just some of the toxic substances found in tobacco smoke²:

• Benzene – A compound in gasoline
• Toluene – Used in paint thinners
• Butane – Found in lighter fluid
• Cadmium – A component of batteries
• Ammonia – Used in household cleaners
• Hydrogen cyanide – Used in chemical weapons

When a person who does not smoke is exposed to secondhand smoke, they inhale all the nicotine and previously described chemicals. The more smoke inhaled, the higher and more toxic the levels in the body become. There is no safe level of exposure to secondhand smoke, and knowing where else these materials are commonly found tells us that even brief exposure can be harmful to our health.

Health Problems Caused by Secondhand Smoking

Effects of Passive Smoking on Health

Second-hand smoke is a significant health hazard, particularly for non-smoking individuals who are exposed to it³. Short-term exposure can lead to coughing like smokers, headaches, eye and nose irritation, and a sore throat. In the long run, it can lead to an increased risk of coronary heart disease, lung cancer, and stroke by 20-30%⁴. About 7,330 deaths from lung cancer are rooted in secondhand smoke, while 33,950 people die from heart disease each year. Secondhand smoke was found to be a definitive cause of stroke, accounting for the deaths of 2.5 million people between 1964 and 2014. 

High-Risk Locations for Passive Smoking

In certain populations, secondhand smoke can have additional devastating impacts. In the workplace, $5.6 billion is lost per year due to reduced productivity attributable to secondhand smoke⁵. There is an increased risk to the health of nonsmokers exposed to secondhand smoke, particularly in restaurants, bars, and casinos, where levels are 2–5 times higher than in the homes of smokers. People living in multi-unit housing are also at increased risk, as secondhand smoke can spread from common areas like hallways, stairwells, and ventilation systems⁶.

Effects of Passive Smoking on Pregnancy and Babies

A significant risk is posed to pregnant women as exposure to secondhand smoke can complicate pregnancy and childbirth, leading to higher rates of stillbirth and congenital birth defects⁷. The baby is more likely to be born before 37 weeks of pregnancy⁸.

They may also have a low birth weight or weigh less than 5 pounds, 8 ounces⁹.

Birth defects such as cleft lip and palate may also be present in the infant at birth, which may cause problems in the child’s development. If exposed to secondhand smoke after birth, babies may be at risk for asthma, bronchitis, ear infections, and pneumonia. This can result in numerous visits to the doctor every year. 

Effect of Secondhand Smoke on Children

Secondhand smoke is especially harmful to children. It is responsible for 150,000 to 300,000 lower respiratory tract infections in infants and children younger than 18 months¹⁰. Exposure to secondhand smoke is also the cause of 7,500 to 15,000 hospitalizations yearly. Secondhand smoke has also been linked to a rise in ear infections, accounting for 790,000 visits to the doctor every year, as well as triggering more asthma flares up in children. Sadly, about 35% (around 23 million) of children in the US are exposed to secondhand smoke and its harmful effects. 

Children tend to breathe faster than adults, taking in more of the toxic chemicals found in tobacco smoke¹¹. Because they are younger and their immune system is still developing, they are at greater risk of breathing problems, illnesses, and infections. They may also have reduced lung function and as a result, may develop wheezing illnesses and asthma. Lastly, secondhand smoke causes fluid in the middle ear to build up, leading to ear infections that involve numerous doctor visits every year. In the long run, the medical consultations, medications, lost school time, and lost work time for parents can be a huge burden¹². 

Protecting Yourself from Secondhand Smoke

Clearly, even brief exposure to secondhand smoke can have detrimental effects. Thankfully, secondhand smoke exposure is preventable. To mitigate health risks, here are some measures to protect yourself and loved ones from secondhand smoke¹³: 

• Avoid spending time around people smoking tobacco products and e-cigarettes
• Eliminate smoking in your home, community, and workplace
• Ask people to avoid smoking around you and your children
• Ensure that your children’s daycare center or school is smoke-free
• Teach children to stay away from smokers and secondhand smoke
• Enforce policies that prevent smoking in all indoor public spaces
• Encourage smokers to quit smoking by joining health groups advocating for smoking cessation

The first step to change begins at the individual level. By taking measures to ensure a smoke-free environment at home and in the workplace, everyone gets an equal opportunity to breathe in clean air and stay healthy. 

FAQ about Passive Smoking

The following answers are based on information provided by the Centers for Disease Control¹⁴, American Cancer Society¹⁵. and the American Lung Association¹⁶.

Conclusion

Secondhand smoke poses a significant public health risk. It not only damages the airways and lungs but also aggravates any underlying respiratory and cardiovascular conditions. Secondhand smoke has a particularly negative impact on children and pregnant women, interfering with their growth and development. It is also implicated in the prevalence of lung cancer and heart attacks. 

The only way to ensure that everyone has access to clean and breathable air is to take measures for a totally smoke-free environment. Teach your children to avoid secondhand smoke and use establishments that are smoke-free. Support smoke-free policies and take steps to reduce your own exposure to second-hand smoke. There are now numerous resources to encourage and help smokers quit smoking. Listed below are links to helpful online resources:

• smokefree.gov (1-800-quit-now)¹⁷
• Centers for Disease Control and Prevention (CDC)¹⁸
• CDC tips for quitting smoking¹⁹
• Amanda’s story: Smoking during pregnancy and premature birth²⁰

1. American Cancer Society. (2023). Health Risks of Secondhand Smoke. Accessed 6th April 2023 from https://www.cancer.org/healthy/stay-away-from-tobacco/health-risks-of-tobacco/secondhand-smoke.html[↩]
2. Centers for Disease Control and Prevention. (2022). Smoking & Tobacco Use. Accessed 6th April 2023 from https://www.cdc.gov/tobacco/secondhand-smoke/about.html[↩]
3. American Lung Association. (2022). Health Effects of Secondhand Smoke. Accessed 6th April 2023 from https://www.lung.org/quit-smoking/smoking-facts/health-effects/secondhand-smoke[↩]
4. National Health Service. (2022). Dangers of Secondhand Smoke. Accessed 6th April 2023 from https://www.nhsinform.scot/healthy-living/stopping-smoking/reasons-to-stop/dangers-of-second-hand-smoke[↩]
5. American Lung Association. (2022). Health Effects of Secondhand Smoke. Accessed 6th April 2023 from https://www.lung.org/quit-smoking/smoking-facts/health-effects/secondhand-smoke[↩]
6. Centers for Disease Control and Prevention. (2022). Smoking & Tobacco Use. Accessed from https://www.cdc.gov/tobacco/secondhand-smoke/about.html[↩]
7. Leonardi-Bee, J., Britton, J., & Venn, A. (2011). Secondhand Smoke and Adverse Fetal Outcomes in Nonsmoking Pregnant Women: A Meta-analysis. Pediatrics, 127(4), 734–741). https://doi.org/10.1542/peds.2010-3041 [↩]
8. K. B., Hahn, E., Hall, L., Rayens, M. K., Noland, M., & Ferguson, J. E. (2010). The Effects of Prenatal Secondhand Smoke Exposure on Preterm Birth and Neonatal Outcomes. Journal of Obstetric, Gynecologic & Neonatal Nursing, 39(5), 525–535). Elsevier BV. https://doi.org/10.1111/j.1552-6909.2010.01169.x[↩]
9. Hawsawi, A. M., Bryant, L. O., & Goodfellow, L. T. (2014). Association Between Exposure to Secondhand Smoke During Pregnancy and Low Birthweight: A Narrative Review. Respiratory Care, 60(1), 135–140). Daedalus Enterprises. https://doi.org/10.4187/respcare.02798[↩]
10. American Lung Association. (2022). Health Effects of Secondhand Smoke. Accessed 6th April 2023 from https://www.lung.org/quit-smoking/smoking-facts/health-effects/secondhand-smoke[↩]
11. National Health Service. (2022). Dangers of Secondhand Smoke. Accessed 6th April 2023 from https://www.nhsinform.scot/healthy-living/stopping-smoking/reasons-to-stop/dangers-of-second-hand-smoke[↩]
12. American Cancer Society. (2023). Health Risks of Secondhand Smoke. Accessed 6th April 2023 from https://www.cancer.org/healthy/stay-away-from-tobacco/health-risks-of-tobacco/secondhand-smoke.html[↩]
13. Centers for Disease Control and Prevention. (2023). How to Protect Yourself and Your Loved Ones from Secondhand Smoke. Accessed 6th April 2023 from https://www.cdc.gov/tobacco/sgr/2006/pdfs/protect-from-shs.pdf[↩]
14. CDC. (2023). How to Protect Yourself and Your Loved Ones from Secondhand Smoke. Accessed 6th April 2023[↩]
15. ACS. (2023). Health Risks of Secondhand Smoke. Accessed 6th April 2023[↩]
16. ALA. (2022). Health Effects of Secondhand Smoke. Accessed 6th April 2023[↩]
17. https://smokefree.gov/[↩]
18. https://www.cdc.gov/tobacco/index.htm[↩]
19. https://www.cdc.gov/tobacco/campaign/tips/index.html[↩]
20. Amanda's story[↩]

Mikaela Millan

Mikaela is a dentistry clinician at the University of the Philippines.