Second-hand smoking (passive smoking)

Risks to people

• Breathing other people’s smoke is called passive, involuntary or second-hand smoking (SHS).
• 80% of second-hand smoking is invisible and contains over 4,000 toxins, putting people at risk of:
  • asthma
  • meningitis
  • bronchitis
  • pneumonia
  • sudden infant death syndrome (SIDS) in babies
  • heart disease
  • cancer.
• Children who live with smokers are twice as likely to become smokers themselves. Watch the video below to find out more.

• It has been estimated that domestic exposure to SHS in the UK causes around 2,700 deaths in people aged 20 year to 63 years and a further 8,000 deaths a year among people aged 65 years and older. People particularly at risk from the effects of secondhand smoke include pregnant women and people with pre-existing heart or respiratory illnesses.

Risks to animals

• Pets are also at risk when exposed to second-hand smoke. A study in the United States found that even limited exposure to tobacco smoke more than doubled a cat’s risk of feline lymphoma. Other studies have found an association between exposure to second-hand smoke and cancer in dogs. Rabbits are also likely to be at risk.
• Animals do not just suffer the ill-effects of inhaling cigarette smoke. The small particles within the smoke settles on their hair and is ingested during grooming. Pets also sometimes swallow cigarettes and other tobacco products causing nicotine poisoning which can be fatal.
• The best way to protect your family and pets from the hidden dangers of second-hand smoke is to find ways of quitting or smoke outside, making sure you shut windows and doors behind you, so the smoke doesn't drift back in.

For more information on second-hand smoking visit nhs.uk/smokefree

Page last updated: 26 October 2023