Second-Hand Smoking

What is Second-hand Smoking?

The smoke produced by burning tobacco products or exhaled by a smoker is known as second-hand tobacco smoke or environmental tobacco smoke (ETS)1. Second-hand smoking is the term describing the exposure to tobacco smoke, or the chemicals in tobacco smoke, without actually smoking.2 This is commonly referred to as involuntary smoking or passive smoking.

Does second-hand smoke affect the health of non-smokers?

Scientific evidence has established that there is no safe level of exposure to second-hand smoke.3 The harmful contaminants found in tobacco smoke often linger indoors for hours and can cause or exacerbate a wide range of adverse health effects, including cancer, respiratory infections, and asthma. Neither ventilation nor filtration, even in combination, can reduce tobacco smoke exposure indoors to levels that are considered acceptable. Only 100% smoke-free environments provide effective protection.4

Second-hand smoke is known to be harmful and hazardous to the health of the general public and particularly dangerous for children. Of the more than 4000 chemicals present in tobacco smoke, more than 60 have been identified as cancer causing chemicals, 11 of which are known to cause cancer in humans and 8 that probably cause cancer in humans.5

What is being done?

There is an international consensus that exposure to second-hand smoke poses significant public health risks. The World Health Organization Framework Convention on Tobacco Control (FCTC) recognises that exposure to tobacco smoke causes death, disease and disability, and asks countries to adopt and implement legislation that provides protection from second-hand smoke.6 Many countries around the world, including Australia, have already introduced laws to protect people from exposure to tobacco smoke in public places, in compliance with Article 8 of the FCTC.7

In Australia, the State and Territory Governments are generally responsible for the regulation of ETS and the development of smoke-free policies. Each of the States and Territories are undertaking reforms in relation to smoking in public and enclosed spaces and have implemented smoking restrictions in areas such as restaurants, bars and shopping centres. Additionally, some States and Territories have introduced bans on smoking in a vehicle when children under the age of 16 are passengers.

Does second-hand smoke affect the health of non-smokers?

Yes. There is substantial evidence that second-hand smoke is a serious health threat. Studies suggest that even brief exposure to second-hand smoke can be harmful and that regular exposure increases the risk of respiratory problems, heart disease, heart attacks, and cancer. Research into smoking in the home indicates that non-smokers who live with a smoker have a 25%-30% greater risk of developing coronary heart disease than those who live in a smoke-free environment.3

Young people regularly exposed to second-hand smoke in the home inhale about the same amount of nicotine as if they were smoking 60-150 cigarettes a year.8 This is enough to be considered an occasional smoker, increasing their risk of lung cancer by 20%-30%, and doubles the likelihood of them becoming a smoker later in life.3,9, In 2007, around 1 in 12 Australian households (8%) with children under 15 years had a household member that smoked inside the home.

A developing baby can be affected by ETS if the mother smokes or if she is exposed to tobacco smoke during pregnancy. Exposure to second-hand smoke during pregnancy can reduce the growth and health of babies and increase the risks of a number of complications and illness for both mother and baby. Babies born to women who smoke during pregnancy have a greater chance of premature birth, low birth weight, stillbirth and infant mortality. Smoking during pregnancy can also affect the development of baby’s lungs which increases the risk for many health problems.3

1) World Health Organisation’s (WHO) Facts on Tobacco and Second-Hand Smoke
2) U.S. Department of Health and Human Services, National Centre for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health. The health consequences of involuntary exposure to tobacco smoke: a report of the Surgeon General 2006.
3) World Health Organization (2007) Protection from exposure to second-hand tobacco smoke
4) Hoffmann D, Hoffman I and El-Bayoumy K. The Less Harmful Cigarette Research in Toxicology 2001, 14(7):767-790.
5) World Health Organisation, Why is smoking an issue for non-smokers
6) The Framework on Tobacco Control (FCTC) Commitments under Article 8: Second-hand Smoke.
7) Quit Victoria. Tobacco in Australia: Facts and Issues 2005: 4.The Health Effects of Passive Smoking
8) Journal of the National Cancer Institute, Stat bite: Cause of lung cancer in non-smokers, Vol. 98, No. 10, May 17, 2006.
9) Australian Institute of Health and Welfare. Australia’s Health 2008: Health across the life stages.