SummaryRead the full fact sheet
- 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 you can’t give up smoking for your own health, perhaps the health of your partner or children, or other members of your household could be a stronger motivation.
- In Victoria, it is illegal to smoke in cars carrying people under 18 years of age.
- If you have never smoked but you live with people who do smoke, you 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 tobacco, electronic cigarettes and shisha tobacco:
- 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
- in 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.
Toxic 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 70 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 or . Exposure to second-hand smoke can trigger or worsen symptoms.
Health risks of passive smoking – pregnant women and unborn babies
Australian data indicates that about 10 per cent of women smoke during pregnancy. Both smoking and passive smoking can seriously affect the developing fetus.
- and low birth weight
- , which includes sudden infant death syndrome (SIDS) and fatal sleep accidents
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 , 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 . There is consistent evidence that people who do not smoke, who live in a smoky household, have higher risks of coronary heart disease and stroke 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 and .
- 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 .
- There is increasing evidence that passive smoking can increase the risk of nasal sinus cancer, , larynx cancer, , long- and short-term respiratory symptoms, loss of lung function, and among people who do not smoke.
Passive smoking – a good reason to quit
The risks of active smoking are well known. If you are struggling to give up smoking for your own health, you might find that the health of your family or other members of your household is be a stronger motivation.
Reducing the risk of passive smoking
If you smoke but you are unwilling or unable to stop immediately, there are various ways to help protect the health of the people you live with. 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.
- Make sure that all people who look after your children provide a smoke-free environment.
Where to get help
- , 2017, Quit Victoria.
- Collins D, Lapsley H 2008, , Monograph Series no. 64, Department of Health and Ageing, Canberra.
- , 2014, US Department of Health and Human Services.
- , 2018, Quit Victoria.
- Campbell M, Ford C, Winstanley M 2017, ‘’, in M Scollo and M Winstanley (eds), Tobacco in Australia: Facts and issues, Cancer Council Victoria.
- , 2010, US Department of Health and Human Services.
- , 2018, Australian Institute of Health and Welfare, Perinatal statistics series no. 34. Cat no. PER 97, Canberra.
- , IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, International Agency for Research on Cancer.