Summary

  • Passive smoking means breathing in other people’s tobacco smoke.
  • Second-hand smoke has been confirmed as a cause of lung cancer in humans by several leading health authorities.
  • Passive smoking increases the risk of respiratory illnesses in children, including asthma, bronchitis and pneumonia.
  • If a person who smokes can’t give up for their own health, perhaps the health of their partner or children, or other members of their household, will be a stronger motivation.
  • In Victoria, it is illegal to smoke in cars carrying people under 18 years of age.
  • People who have never smoked who live with people who do smoke are at increased risk of a range of tobacco-related diseases, including lung cancer, heart disease and stroke.
Passive smoking means breathing in other people’s tobacco smoke. Exhaled smoke is called exhaled mainstream smoke. The smoke drifting from a lit cigarette is called sidestream smoke. The combination of mainstream and sidestream smoke is called second-hand smoke (SHS) or environmental tobacco smoke (ETS). Second-hand smoke is a serious health risk for both those who smoke and those who do not. Children are particularly at risk of serious health effects from second-hand smoke.

Tobacco laws in Victoria

In Victoria, it is illegal to smoke:

  • in most indoor workplaces 
  • within the grounds of, and at and within four metres of an entrance to, all Victorian childcare centres, kindergartens (or preschools) and primary and secondary schools
  • at and within four metres of an entrance to children’s indoor play centres and Victorian public premises ( all public hospitals and registered community health centres, and certain Victorian Government buildings)
  • in cars carrying people who are under 18 years of age
  • at all of Victoria's patrolled beaches within 50 metres of a red and yellow flag
  • within ten metres of outdoor children's playground equipment
  • within ten metres of outdoor skate parks
  • within the outdoor areas of all public swimming pool complexes
  • within ten metres of outdoor sporting venues during under 18s events and training sessions
  • on public transport
  • in all areas of train stations, covered bus shelters, raised platform tram stops and all tram stop shelters
  • on the grounds of prisons
  • at underage music or dance events.

From 1 August 2017, smoking will also be prohibited in the following areas:

  • all outdoor dining areas where food (other than pre-packaged food or uncut fruit) is provided on a commercial basis
  • at certain food fairs and organised events.

In addition, from 1 August 2017 the use of electronic cigarettes will be prohibited in all of the above legislated smoke-free areas.
For more information on tobacco laws in Victoria, visit the Victorian Department of Health and Human Services page on tobacco reforms

Irritant effects of passive smoking

Tobacco smoke inside a room tends to hang in mid-air rather than disperse. Hot smoke rises, but tobacco smoke cools rapidly, which stops its upward climb. Since the smoke is heavier than the air, the smoke starts to descend. 

A person who smokes heavily indoors creates a low-lying smoke cloud that other householders have no choice but to breathe. 

Tobacco smoke contains around 7,000 chemicals, made up of particles and gases, over 50 of which are known to cause cancer. Second-hand smoke has been confirmed as a cause of lung cancer in humans by several leading health authorities. 

Compounds such as ammonia, sulphur and formaldehyde irritate the eyes, nose, throat and lungs. These compounds are especially harmful to people with respiratory conditions such as bronchitis or asthma. Exposure to second-hand smoke can either trigger or worsen symptoms.

Health risks of passive smoking – pregnant women and unborn babies

Australian data indicates that about 11 per cent of women smoke during pregnancy. Both smoking and passive smoking can seriously affect the developing fetus.

Health risks for mothers who smoke during pregnancy include increased risk of: 

A non-smoking pregnant woman is more likely to give birth earlier, and to a baby with a slightly lower birth weight if she is exposed to second-hand smoke in the home – for example, if her partner smokes.

Health risks of passive smoking – children

Children are especially vulnerable to the damaging effects of second-hand smoke. Some of the many health risks include: 

  • Passive smoking is a cause of sudden unexpected death in infants (SUDI), which includes sudden infant death syndrome (SIDS) and fatal sleep accidents. 
  • A child who lives in a smoking household for the first 18 months of their life has an increased risk of developing a range of respiratory illnesses, including bronchitis,bronchiolitis and pneumonia. They are also more prone to getting colds, coughs and glue ear (middle ear infections). Their lungs are weaker and do not grow to their full potential.
  • A child exposed to second-hand smoke in the home is more likely to develop asthma symptoms, have more asthma attacks and use asthma medications more often and for a longer period. 
  • School-aged children of people who smoke are more likely to have symptoms such as cough, phlegm, wheeze and breathlessness.
  • Children of people who smoke have an increased risk of meningococcal disease, which can sometimes cause death or disability.

Health risks of passive smoking – partners who have never smoked

People who have never smoked who live with people who do smoke are at increased risk of a range of tobacco-related diseases and other health risks, including: 

  • Passive smoking increases the risk of heart disease. There is consistent evidence that people who do not smoke, who live in a smoky household, have higher risks of coronary heart disease than those who do not. 
  • Passive smoking makes the blood more ‘sticky’ and likely to clot, thereby leading to increased risk of various health conditions, including heart attack and stroke
  • There is evidence that passive smoking is associated with lower levels of antioxidant vitamins in the blood.
  • Just 30 minutes of exposure to second-hand smoke can affect how your blood vessels regulate blood flow, to a similar degree to that seen in people who smoke.
  • Long-term exposure to passive smoking may lead to the development of atherosclerosis (narrowing of the arteries). 
  • People who do not smoke who suffer long-term exposure to second-hand smoke have a 20 to 30 per cent higher risk of developing lung cancer.
  • There is increasing evidence that passive smoking can increase the risk of nasal sinus cancer, throat cancer, larynx cancer, breast cancer, long- and short-term respiratory symptoms, loss of lung function, and chronic obstructive pulmonary disease among people who do not smoke.
  • It is estimated that in Australia, in the financial year 2004–05, 113 adults and 28 infants died from diseases caused by second-hand smoke in the home.
    Passive smoking – a good reason to quit

The risks of active smoking are well known. If a person who smokes can’t give up for their own health, then the health of their family or other members of their household could be a stronger motivation. 

There is a wealth of assistance and support for people who wish to stop smoking. See your doctor for further information and advice, or ring the Quitline on 13 7848.

 

Reducing the risk of passive smoking

If a person who smokes is unwilling or unable to stop immediately, there are various ways to help protect the health of the people with whom they live. Suggestions include: 

  • Make your home smoke-free. Limiting your smoking to one or two rooms is not an effective measure – tobacco smoke can easily drift through the rest of the house.
  • Make sure that visitors to your house smoke their cigarettes outdoors.
  • Make your car smoke-free. The other occupants will still be exposed to tobacco smoke even if the windows are open. In Victoria, it is illegal to smoke in cars carrying people who are under 18 years of age.
  • Don’t allow smoking in any enclosed space where people who do not smoke spend time – for example, in the garage, shed, cubby house, boat or caravan.
  • Try to avoid taking children to outdoor areas where people are smoking and you can’t easily move away, such as a café courtyard.
  • Make sure that all people who look after your children provide a smoke-free environment.

Where to get help

  • Your doctor
  • Pharmacist
  • Quitline. Tel. 13 7848
References
  • What is secondhand smoke? 2015, Quit Victoria. More information here.
  • The costs of tobacco, alcohol and illicit drug abuse to Australian society in 2004–05 2008, Collins D, Lapsley H, Monograph Series no. 64, Department of Health and Ageing, Canberra. More information here.
  • The health consequences of smoking – 50 years of progress: a report of the Surgeon General, 2014, US Department of Health and Human Services. More information here.
  • What is secondhand smoke? 2015, Quit Victoria. More information here.
  • Campbell M, Ford C, Winstanley M 2012, ‘Chapter 4 – The health effects of secondhand smoke’, in M Scollo and M Winstanley (eds), Tobacco in Australia: Facts and issues, Cancer Council Victoria. More information here.
  • How tobacco smoke causes disease: the biology and behavioral basis for smoking-attributable disease: a report of the Surgeon General, 2010, US Department of Health and Human Services. More information here.
  • Australia's mothers and babies 2014 – in brief, 2016, Australian Institute of Health and Welfare, Perinatal statistics series no. 32. Cat no. PER 87, Canberra. More information here.

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Last updated: March 2017

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