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Secondhand smoke and the health of people around you

When you smoke, the people around you inhale the smoke you breathe out and the smoke burning from the cigarette. This is called secondhand smoke. It's very harmful.

Every time you, your partner or a household member smokes, others in the household are breathing in the same dangerous chemicals.

What’s in cigarette smoke?

  • Tar – a sticky brown substance that contains cancer-causing chemicals.

  • Carbon monoxide – a poisonous gas that reduces the amount of oxygen carried by the blood.

  • Nicotine – the addictive drug in tobacco which plays a role in heart disease.

  • 7000 chemicals that can harm the lungs and contribute to disease, including at least 69 known carcinogens. 

Secondhand smoke and health

Because secondhand smoke has a similar make up to the smoke that smokers inhale, the types of health issues associated with active smoking are similar to the types of health issues associated with secondhand smoke. 

Cardiovascular disease appears to be a particular risk to those exposed to secondhand smoke. 

In children and infants, secondhand smoke causes:

  • SIDS (sudden infant death syndrome) or 'cot death’

  • Lower birthweight

  • Bronchitis, pneumonia and other lung/airway infections

  • Wheeze illnesses in early childhood

  • Middle ear disease or 'glue ear'  

  • Respiratory symptoms including cough, phlegm, wheeze and breathlessness

  • Higher rates and worsening of asthma

  • Weaker lungs: lower level of function during childhood

In children and infants, secondhand smoke is linked to:

  • Development of asthma

  • Preterm delivery 

  • Childhood cancers: liver cancer, leukemias and lymphomas (where both the pregnant mother and the child, after birth, were exposed to secondhand smoke

  • Tooth decay

  • Breathing complications during and after surgury 

  • Worsening of cystic fibrosis

  • Meningococcal disease

In adults, secondhand smoke causes:

  • Heart disease

  • Stroke

  • Lung cancer

  • Irritation of the eyes and nose

In adults, secondhand smoke is linked to:

  • Cancers of the breast, throat, voice box, nose and cervix

  • Diabetes

  • Disease of the blood vessels

  • Short-term respiratory problems including cough, wheeze, chest tightness and difficulty breathing

  • Long-term respiratory problems

  • Small loss of lung function

  • Development of asthma and worsening of asthma control

  • Chronic obstructive pulmonary disease (COPD)

Secondhand smoke and other health issues

  • Fertility: secondhand smoke can also affect fertility. If your partner smokes it can affect both your fertility and your partner’s fertility. 

  • The home: not only does smoke hang in the air, the chemicals in this smoke sit on clothes and furniture. 

  • Pets: secondhand smoke can affect the health of pets. This includes this risk of several different cancers. 

What to do about secondhand smoke?

The best way to protect your loved ones from secondhand smoke is to quit smoking. The next best way is to have a total smoking ban inside your home, and to change smoke-filled clothing before carrying babies and children.

For tips, talk to one of our Quitline counsellors from the Quitline or request a Quitline callback

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