Secondhand smoke is the combination of smoke that's exhaled by smokers (exhaled mainstream smoke) and smoke that drifts from the burning end of a cigarette (sidestream smoke).1
Breathing in this secondhand smoke is called passive smoking.1
If you smoke, it's important that you realise how your smoking may be affecting those around you and then make a plan to protect them – by asking for the support you need to quit smoking for good.
- There is no safe level of passive smoking2
All passive smoking poses a risk to those around you, from family and friends, to your pets, too! Just being around someone else's smoke for a short time can be harmful to health.2
- There are more than 4000 chemicals in secondhand smoke3
This cocktail of chemicals includes at least 250 that are toxic to the human body and 50 that are known carcinogens – substances that cause cancer.3 As well as these chemicals, secondhand smoke contains particulate matter – microscopic solids and liquids that are suspended in air, which, when inhaled, can cause serious health problems.3
- Sidestream smoke is more toxic than mainstream smoke3
The particulate matter in sidestream smoke is 3–4 times more toxic than the mainstream smoke inhaled by smokers. And the toxicity increases another 2–4 times as the smoke ages – this is when old smoke lingers in confined areas – meaning that aged sidestream smoke is about 12 times more toxic than mainstream smoke. This higher toxicity helps to explain why secondhand smoke has such an impact on health, even though non-smokers inhale much less smoke than actual smokers.
- Secondhand smoke harms unborn babies1
Both smoking and passive smoking during pregnancy can have serious effects on an unborn baby. Read more about the effects of smoking on unborn babies.
- Secondhand smoke is especially dangerous to children
Children are especially vulnerable to the effects of secondhand smoke because of their higher breathing rates, and the immaturity and greater surface area of their lungs. Young children can't choose to leave a smoke-filled place like adults can, and this can increase the amount of secondhand smoke they're exposed to.4 All this can result in health problems ranging from asthma to ear infections and sudden infant death syndrome (SIDS).1 Read about the health problems that secondhand smoking causes in children and how you can help to protect them.
- Passive smoking can cause heart disease, heart attack and stroke5
Exposure to secondhand smoke has a damaging effect on the heart, blood vessels and blood where it can increase the risk of having a heart attack. Non-smokers exposed to secondhand smoke have a 25–30% increased risk of heart disease and 20–30% increased risk of stroke.
- Passive smoking can cause lung cancer5
Secondhand smoke can cause lung cancer in people who have never smoked. Non-smokers who are exposed to secondhand smoke have a 20–30% increased risk of developing lung cancer. Even short periods of exposure to secondhand smoke can be enough to damage cells and start the process of cancer developing.
- Secondhand smoke kills6
Estimate information from the US and UK shows that for every 10 deaths caused by smoking amongst smokers, 1 death occurs in a non-smoker who has been exposed to secondhand smoke.
- Banning smoking in public places has huge benefits for everyone
Laws which have banned smoking in public places have led to improvements in air quality, reduced exposure to secondhand smoke,7 rapid reductions in acute heart events,8 and reduced flare-ups of asthma.8 These laws have motivated many smokers to quit8 and gone some way to preventing young people from taking up smoking in the first place.7
Are you ready to protect everyone around you from the risks of passive smoking?
Now that you've seen the cold, hard facts about passive smoking, we hope you're feeling more committed than ever to quitting.
Quitting smoking begins by having a plan and then enlisting the support of your doctor, family and friends to help you move towards a smoke-free life that will have huge rewards for you and everyone around you. Remember, you're 4x more likely to succeed in quitting with the help of a healthcare professional compared to quitting unaided.9
© Pfizer 2018. Pfizer Australia Pty Limited. Pfizer Medical Information: 1800 675 229. Sydney, Australia. PP-CHM-AUS-0450, 05/2018
1 Better Health Channel. Passive smoking Available at https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/passive-smoking. Accessed 22 February 2018.
2 CDC. Centers for Disease Control and Prevention. Secondhand Smoke (SHS) Facts. Available at https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/general_facts/index.htm. Accessed 22 February 2018.
3 Tobacco in Australia. Facts & Issues. Chapter 4: 4.2 What is in secondhand smoke? Available at http://www.tobaccoinaustralia.org.au/chapter-4-secondhand/4-2-what-is-in-secondhand-smoke. Accessed 22 February 2018.
4 Tobacco in Australia. Facts & Issues. Chapter 4: 4.17 Health effects of secondhand smoke for infants and children. Available at http://www.tobaccoinaustralia.org.au/chapter-4-secondhand/4-17-health-effects-of-secondhand-smoke-for-infants. Accessed 28 February 2018.
5 CDC. Centers for Disease Control and Prevention. Health Effects of Secondhand Smoke. Available at https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/health_effects/index.htm. Accessed 22 February 2018.
6 Tobacco in Australia. Facts & Issues. Chapter 4: 4.7 Estimates of morbidity and mortality attributable to secondhand smoke. Available at http://www.tobaccoinaustralia.org.au/chapter-4-secondhand/4-7-estimates-of-morbidity-and-mortality. Accessed 2 March 2018.
7 Intergovernmental Committee on Drugs. National Tobacco Strategy 2012–2018: 6.8 Reduce exceptions to smoke-free workplaces, public places and other settings – pg 33. Available at http://www.nationaldrugstrategy.gov.au/internet/drugstrategy/publishing.nsf/Content/D4E3727950BDBAE4CA257AE70003730C/$File/National%20Tobacco%20Strategy%202012-2018.pdf. Accessed 2 March 2018.
8 Tobacco in Australia. Facts & Issues. Chapter 15: 15.10 Effects of smokefree legislation on health outcomes. Available at http://www.tobaccoinaustralia.org.au/chapter-15-smokefree-environment/15-10-effects-of-smokefree-legislation-on-health-outcomes. Accessed 3 March 2018.
9 West R (2012) Stop smoking services: Increased chances of quitting. NCSCT Briefing #8. London; National Centre for Smoking Cessation and Training.