Passive smoking

Passive smoking means breathing in other people’s tobacco smoke. A smoker’s exhaled smoke is called exhaled mainstream smoke. The smoke drifting from their lit cigarette is called sidestream smoke. The combination of mainstream and sidestream smoke is called second-hand smoke (SHS) or environmental tobacco smoke (ETS).

Most of the smoke that hangs in a room is sidestream smoke, which contains higher levels of cancer-causing compounds than mainstream smoke. Second-hand smoke is a common indoor pollutant in the home, making passive smoking a serious health risk for both smokers and nonsmokers. Children are particularly at risk of serious health effects from second-hand smoke.

In Victoria, it is illegal to smoke in cars carrying children under 18 years of age.

Irritant effects

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 heavy smoker who smokes indoors causes a permanent low-lying smoke cloud that other householders have no choice but to breathe.

Tobacco smoke contains around 4,000 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 – unborn babies

Australian data indicates that about 17 per cent of women smoke during pregnancy, although this percentage appears to be going down. Both smoking and passive smoking can seriously affect the developing fetus.

Health risks for mothers who smoke during pregnancy include:

• Increased risk of miscarriage and stillbirth
• Increased risk of premature birth and low birth weight
• Increased risk of sudden unexpected death in infancy (SUDI), which includes sudden infant death syndrome (SIDS) and fatal sleep accidents
• Increased risk of complications during the birth.

A nonsmoking pregnant woman is more likely to give birth 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 – 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 infancy (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 wheeze, bronchitis, bronchiolitis and pneumonia. They are also more prone to getting colds, coughs and glue ear (middle ear infections). Their lungs show a reduced ability to function and slower growth.
• 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 smokers are more likely to have symptoms such as cough, phlegm, wheeze and breathlessness.
• Children of smokers have an increased risk of meningococcal disease, which can sometimes cause death or disability.

Health risks – partners who have never smoked

People who have never smoked, but who live with partners who smoke, are at increased risk of a range of tobacco-related diseases.

Some of the many health risks for partners who have never smoked include:

• Passive smoking increases the risk of heart disease. There is consistent evidence that nonsmokers married to smokers have higher risks of coronary heart disease than those whose spouses do not smoke.
• Passive smoking makes the blood more ‘sticky’ and likely to clot. There is evidence that levels of antioxidant vitamins in the blood are also reduced.
• Just 30 minutes of exposure to second-hand smoke can affect how your blood vessels regulate blood flow to a similar degree that is seen in smokers.
• Long-term exposure to passive smoking may lead to the development of atherosclerosis (narrowing of the arteries).
• Nonsmokers 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 stroke, nasal sinus cancer, throat cancer, breast cancer, long and short-term respiratory symptoms, loss of lung function, and chronic obstructive pulmonary disease among nonsmokers.
• 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.

Quit smoking as soon as you can

The risks of active smoking are well known. If a smoker can’t give up for their own health, the health of their partner or children could be a stronger motivation. There is a wealth of assistance for smokers who wish to stop smoking. See your doctor for further information and advice, or ring the Quitline on 13 7848 (13 QUIT).

Reducing the risk of passive smoking

If the smoker is unwilling or unable to stop right now, there are various ways to help protect the health of their partner and children. Suggestions include:

• Make your home smoke-free. Some smokers think that limiting their smoking to one or two rooms is an effective measure, but tobacco smoke easily drifts through the rest of the house.
• Make sure that smokers who visit the house smoke their cigarettes outdoors, no matter what the weather. If they object or take offence, try calmly explaining the health risks of passive smoking, and point out that you simply want to protect the health of your family.
• Make your car smoke-free. The other occupants will still be exposed to tobacco smoke even if the windows are open. It is illegal to smoke in cars carrying children under 18 years of age.
• Don’t allow smoking in any enclosed space where your partner or children spend time – for example inside the garage, shed, cubby house, boat or caravan.
• Try to avoid taking your 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 (for example, grandparents or babysitters) provide a smoke-free environment.

Where to get help

• Your doctor
• Your pharmacist
• Quitline Tel. 13 7848 (13 QUIT)
• For more information on living smoke-free, visit www.smokefree.org.au.

Things to remember

• In Victoria, it is illegal to smoke in cars carrying children under 18 years of age and in enclosed workplaces.
• If a smoker can’t give up for their own health, perhaps the health of their partner or children will be a stronger motivation.
• Passive smoking increases the risk of respiratory illnesses in children, including asthma, bronchitis and pneumonia.
• People who have never smoked who live with smoking partners are at increased risk of a range of tobacco-related diseases including lung cancer, heart disease and stroke.

You might also be interested in:

• Asthma and smoking.
  
• Asthma children and smoking.
  
• Lung cancer in non-smokers.
  
• Smoking - effects on your body.
  
• Smoking tobacco is deadly.
  

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Last reviewed: August 2011

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<a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Passive_smoking?open">Passive smoking - Better Health Channel</a><br/>
Passive smoking means breathing in other people's tobacco smoke from cigarettes, cigars, pipes and other sources. Second-hand smoke is a danger to everyone, but children, pregnant women and the partners of smokers are most vulnerable. Passive smoking increases the risk of sudden infant death syndrome (SIDS or cot death), middle ear disease, asthma, respiratory illnesses, lung cancer and coronary heart disease.

Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your qualified health professional. Content has been prepared for Victorian residence and wider Australian audiences, and was accurate at the time of publication. Readers should note that over time currency and completeness of the information may change. All users are urged to always seek advice from a qualified health care professional for diagnosis and answers to their medical questions.

For the latest updates and more information, visit www.betterhealth.vic.gov.au

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