Passive smoking can occur when you are in the same room, house, car or public place as smokers. The smoke contains toxic substances that can damage the health of anyone who breathes it in, especially babies, children and pregnant women.

Where does second-hand smoke come from?

The smoke comes from:

• the burning ends of cigarettes, pipes or other tobacco products
• the lungs, noses or mouths of smokers

Do e-cigarettes (vaping) create second-hand smoke?

Breathing in vapours from other people's e-cigarettes (or, 'vapes') is not the same as passive smoking because no cigarette smoke is involved.

However, passive vaping may still harm your health because the vapour from e-cigarettes contains liquid chemicals and other toxic substances which are linked to heart and lung diseases, including cancer.

How does passive smoking affect your health?

Passive smoking can increase the risk of illness and premature death in babies, children and adults. Tobacco smoke contains hundreds of toxic chemicals, including about 70 substances that can cause cancer. Even small amounts are harmful.

In babies, passive smoking can contribute to sudden infant death syndrome, possibly because chemicals from the smoke affect the brain and interfere with breathing.

Babies and children exposed to passive smoking may also get other illnesses such as:

• certain childhood cancers
• asthma
• acute infections of the lungs and respiratory system
• ear problems

In adults, second-hand smoke can increase the risk of:

• lung cancer
• coronary heart disease
• stroke
• wheezing, shortness of breath and asthma

In pregnant women, the effects of passive smoking can include:

• impeding the lung development of the baby
• premature birth
• low birth weight

Who is at greatest risk?

Babies and children are at risk from passive smoking because they cannot control or move out of their environment.

People who live in overcrowded conditions with smokers are also at risk.

How to reduce exposure to passive smoking

The only way to totally protect people from second-hand smoke is not to allow smoking in homes and other indoor spaces.

In Australia, state and territory laws ban smoking in public indoor spaces such as nursing homes, schools, offices, shopping malls, buses and trains. Some states ban smoking in cars if any children under the age of 16 or 18 years old are present.

Smoke-free and tobacco control laws vary from state to state, so check your state's legislation to ban smoking in public spaces for the latest information. In most states and territories, you can't use e-cigarettes in public places where you're also prohibited from smoking cigarettes.

There is also national legislation banning smoking on domestic and international flights, as well as interstate buses. The law allows airports to put up no smoking signs.

To protect yourself and your children:

• insist your home is smoke-free
• ask your partner, family or friends to smoke outside — it is not enough for them to go to another room, since smoke can move through the house
• encourage the smoker to quit — even the smoke particles on clothes can harm people

Ask colleagues or family members using e-cigarettes to vape outside.

What can I do about second-hand smoke if I am a smoker?

If you are a smoker, consider quitting. If you'd like help and support, go to the Quitline website or call 13 7848.

To protect non-smokers from your smoke:

• obey the law in smoke-free public spaces
• at home, smoke outdoors, far away from other people, especially babies and children
• don't smoke near playgrounds or other places where there are children or pregnant women
• stay downwind of people in parks or picnic spots
• respect other people's right to a smoke-free environment