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Secondhand smoke

Please Keep Me Smokefree Drawings

View drawings by local primary school children promoting smokefree areas.

What is secondhand smoke?

Secondhand smoke is simply other people's tobacco smoke, and is also known as passive smoke or environmental tobacco smoke (ETS).

Secondhand smoke is made up of the smoke from the burning end of the cigarette plus the smoke that the smoker breathes out. But it is the smoke from the burning end of the cigarette that makes the most secondhand smoke, and this smoke is poisonous as it contains high concentrations of toxic chemicals such as hydrogen cyanide, ammonia, carbon monoxide and acrolein.

Why is secondhand smoke bad for health?

Secondhand smoke can cause very serious health problems - it does more than cause unpleasant side effects in some people like sore eyes, headaches, throat irritation and coughing.

Being exposed to secondhand smoke can increase a non-smoker's risk of getting lung cancer by 24% and the risk of getting heart disease by 25%, as well as being associated with many other medical conditions like the respiratory disease COPD and other types of cancer.

There is no risk-free level of exposure to secondhand smoke. Just 30 minutes breathing in secondhand smoke can make blood platelets becomes more sticky, which means the person has a higher risk of having a heart attack or developing other heart problems.

Being in an enclosed place where people are smoking can be harmful, even if it does not appear smoky as 85% of secondhand smoke is invisible and odourless.

Secondhand smoke can also linger in an enclosed place long after someone has been smoking. Scientists have also found that ventilation systems are not able to eliminate the risks of secondhand smoke.

The World Health Organisation's International Agency for Research on Cancer says that tobacco smoke is a substance that causes cancer in humans (a carcinogen). Other health and scientific organisations have also classified secondhand smoke as a carcinogen - like the poisonous substances arsenic, asbestos, and radon.

Secondhand smoke is particularly bad for health of children, causing serious medical conditions including childhood respiratory disease, middle ear disease and SIDS. Pregnant women who breathe in secondhand smoke can also pass on harmful chemicals to their babies.

Across the world and in a very short space of time, smokefree laws have proved to be highly effective in protecting people from the harm of secondhand smoke.

What does secondhand smoke contain?

Tobacco smoke contains a cocktail of over 4,000 different chemicals, many of which are toxic and damaging to health. Scientific research shows that secondhand smoke contains more than 50 known substances that cause cancer in humans.

Some killers in secondhand smoke that are hiding right beneath our noses include:

  • Tar: which is known to cause cancer and lung damage
  • Carbon monoxide: which is a toxic gas found in car exhaust fumes
  • Benzene: which is found in petrol fumes and causes leukaemia
  • Ethanol: which is found in anti-freeze
  • Formaldehyde: which is an embalming fluid
  • Hydrogen cyanide: which is classed as an industrial pollutant
  • Arsenic: which is effectively rat poison
  • Polycyclic aromatic hydrocarbon: which is found in diesel exhaust

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