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revised November 30, 2018

Arrow BulletSecond-hand Smoke: the Health Effects

No amount of second-hand smoke is safe

Second-hand smoke (SHS) is:

  • The smoke from the burning end of a cigarette, cigar or pipe.
  • The smoke breathed out by a smoker.
  • Tobacco smoke lingers on clothes and other surfaces even after a cigarette, pipe or cigar has been put out 1
  • This lingering tobacco smoke has recently been called third-hand smoke1
Second-hand smoke causes lung cancer and heart disease in adults.1

Why second-hand smoke is dangerous
How second-hand smoke harms children
Protecting children from second-hand smoke
Smoking in child care centres
Smoking with children in the car
More about smoking and smoke-free spaces
Thinking about Quitting Smoking

Why second-hand smoke is dangerous to health

  • No amount of second-hand smoke is safe.2
  • Second-hand smoke contains over 4,000 chemicals. More than 50 of these chemicals are known or suspected to cause cancer. 2
  • Second-hand smoke causes lung cancer and heart disease in adults.2

Second-hand smoke spreads through all rooms of a building, harming the health of everyone exposed. 3

Making your home or car 100% smoke-free is the only way to avoid the harmful effects of SHS.

How second-hand smoke harms children

Children are especially at risk to the health dangers of second-hand smoke.

  • Second-hand smoke (SHS) is more harmful for children because their lungs are smaller and they breathe more rapidly than adults. 3
  • Children exposed to SHS are more likely to develop asthma, ear infections, bronchitis and pneumonia. 3
  • Babies who regularly breathe second-hand smoke have a greater chance of dying from Sudden Infant Death Syndrome (SIDS) (also known as ‘crib death’). 2
  • Exposure to second-hand smoke is a serious health risk for growing children. Studies show SHS has negative effect on how well children pay attention, think and behave.4

Protecting children from second-hand smoke

Children can’t avoid second-hand smoke by themselves.

It’s our responsibility — as parents, caregivers and child care providers — to protect children from exposure by keeping their indoor and outdoor environments smoke-free.

Smoking in Child Care Centres

The Smoke-Free Ontario Act prohibits smoking in day nurseries* and licensed private-home day cares * .

This does NOT apply to unlicensed child care providers – although they should be encouraged to provide smoke-free environments as well.

For more information about this, please refer to

Smoking with children in the car

  • Since January 21, 2009, smoking inside a vehicle with a child under the age of sixteen has been against the law. 5
  • It doesn’t matter if the vehicle is parked or moving, or whether a door, window or sunroof is open. 6
  • Both drivers and passengers could be charged for smoking while someone under sixteen years old is present in the vehicle 6
  • Please visit the Ontario Ministry of Health Promotion website for more information about this new change to the Smoke-Free Ontario Act.

More about smoking and smoke-free spaces

Call us at 905-799-7700 (toll-free from Caledon at 905-584-2216) for more information about the health effects of smoking, second-hand smoke and how to create smoke-free spaces.


1 Winickoff, Jonathan P., Friebely, Joan, Tanski, Susann E. , Sherrod, Cheryl et al. Beliefs about the Health Effects of  “Thirdhand” Smoke and Home Smoking Bans. Pediatrics: January 2009: 123 (1): e74-e79.

2 Ontario Ministry of Health Promotion, 2006: (fact sheet) Health Effects of Second-Hand Smoke. [PDF]

3 Health Canada, 2006: Make your Home and Car Smoke-Free: A Guide to Protecting your Family from Second-Hand Smoke. [PDF]

4 Ontario Medical Association, 2004: Exposure to Second-Hand Smoke: Are we Protecting our Kids? Toronto: Ontario Medical Association. [PDF]
* As defined by the Government of Ontario (1990) Day Nurseries Act, R.S.O. 1990, c. D.2

5 Government of Ontario. (1994). Smoke-Free Ontario Act, S.O. 1994 c. 10 Accessed February 5, 2010. Available from: http://www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_94t10_e.htm

6 Ontario Ministry of Health Promotion, 2009.  “Smoking in Motor Vehicles with Children Present” (fact sheet).

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