Secondhand smoke
Why is secondhand smoke so bad for health?
What does secondhand smoke contain?
Giving up smoking
What is secondhand smoke?
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 so 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. After just thirty minutes, breathing in secondhand smoke can make blood platelets become 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 is not 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 the 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?
Some other 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
View a list of other chemicals found in secondhand smoke (pdf, 0.5MB) (26.3kb)
Giving up smoking
To find out about the local NHS Stop Smoking Service nearest you, phone the NHS Smoking Helpline free on 0800 169 0 169.
- go to: www.nhs.uk/gosmokefree (new window)
- text 'GIVE UP' and your full postcode to 88088
- ask at your GP, pharmacy or hospital.
View reports and documentation on smoking and the health effects
