How dangerous is second-hand smoke?

Second-hand smoke is more than a nuisance—it is a toxic mix of more than 4,000 chemicals.  In 1992 the U.S. Environmental Protection Agency (EPA) classified second-hand smoke as a “Group A” carcinogen. This category is reserved for the most dangerous compounds that have been proven to cause cancer in humans.

In 2006 the State of California added second-hand smoke to its toxic air contaminant list, putting it in the same category as the most toxic automotive and industrial air pollutants. Over 50 cancer-causing chemicals have been found in second-hand smoke, including arsenic, cadmium, benzene and vinyl chloride.

There is NO known safe level of exposure.

Because second-hand smoke particles are so small (less than 2.5 micrometres), they can actually penetrate the alveoli deep in the lungs where oxygen and carbon dioxide are exchanged. Each year in Canada, breathing second-hand smoke causes more than 1,000 deaths in non-smokers from lung cancer and heart disease, and keeps thousands more from leading normal, healthy lives.

The most comprehensive scientific report on the health consequences of second-hand smoke was conducted by the US Surgeon General in 2006 and should be a wake-up call for non-smokers and smokers alike. The US Surgeon General’s Report warns that no amount of second-hand exposure is safe.

Major conclusions from the report reveal that:

  • Second-hand smoke causes premature death and disease in children and adults who do not smoke;
  • There is no risk-free level of exposure to second-hand smoke;
  • Eliminating smoking in indoor spaces fully protects non-smokers from exposure. Separating smokers from non-smokers, cleaning the air, and ventilating buildings cannot eliminate exposures of non-smokers to second-hand smoke.

1.  Second-hand smoke increases risk of heart disease and lung cancer

  • Concentrations of cancer-causing and toxic chemicals are potentially higher in second-hand smoke than in the smoke inhaled by smokers;
  • Chronic exposure to second-hand smoke increases a non-smoker’s risk of developing heart disease by 25 to 30 percent and lung cancer by 20 to 30 percent;
  • Breathing second-hand smoke for even a short time can have immediate negative effects on the cardiovascular system and interferes with the normal functioning of the heart, blood, and vascular systems;
  • Persons who already have heart disease are especially at high risk of suffering negative affects from breathing second-hand smoke. They should take extra precautions to avoid even brief exposure.

2.  Second-hand smoke causes acute respiratory problems

  • Second-hand smoke contains many chemicals that can quickly irritate and damage the lining of the airways;
  • Even brief exposure can trigger respiratory symptoms including cough, phlegm, wheezing, and breathlessness;
  • Persons with asthma or other respiratory conditions are at especially high risk, and should take extra precautions to avoid breathing second-hand smoke.

3.  Exposure to second-hand smoke harms children

  • Babies exposed to second-hand smoke are at a greater risk for Sudden Infant Death Syndrome (SIDS);
  • Babies exposed to second-hand smoke have weaker lungs than unexposed babies, which increases the risk for many health problems;
  • Among infants and children, second-hand smoke cause bronchitis and pneumonia, and increases the risk of ear infections;
  • Second-hand smoke exposure can cause children with asthma to experience more frequent and severe attacks.

In addition, findings from a 2009 Canadian Expert Panel on Tobacco Smoke and Breast Cancer Risk confirm that exposure to second-hand smoke can cause breast cancer in younger, primarily pre-menopausal women.

How does second-hand smoke get from one unit to another?

Due to differences in air pressure between units, floors, and the inside and outside of a building, air is forced through openings, cracks and other leakage paths. The Canada Mortgage and Housing Corporation describes three main “driving forces” that tend to dictate air movement in multi-storey buildings in the winter months:

  • The “stack effect” causes air to be drawn in from outside at the lower levels of the building, rise up through the floor levels and then leak out of the building at the upper floors;
  • The “wind effect” will cause air to leak into units on the windward side of the building, and flow across the common corridors to units on the leeward side of the building; and
  • Mechanical ventilation systems will also cause the transfer of air to and out of your unit.

Human activity, such as opening and closing windows and doors, and turning on and off fans, also alters air movement patterns.

The take-away message is that air transfer between units is complex–and the solution to minimizing air transfer in one building won’t necessarily work for the next.

For more information, consult Solving Odour Transfer Problems in Your Apartment published by the Canada Mortgage and Housing Corporation.

Are there provincial or municipal smoke-free laws that apply to housing co-operatives?

Yes. Under the provincial Smoke-Free Ontario Act, smoking is prohibited in the common areas of public places (which includes your building) including the corridors, elevators, laundry room, enclosed parking garage, etc. This is true regardless of the number of units in the building.

Municipal governments have the authority to ban or restrict smoking in public places within their geographic limits and to create smoking bylaws that exceed Ontario’s smoke-free legislation. There is a growing number of municipalities in this province that have passed bylaws prohibiting smoking within a certain distance from doorways to public places and/or buildings owned or leased by the municipality. Contact your local municipality to find out if any such bylaws apply to your building, or visit the Non-Smokers’ Rights Association online for more information.

If members are smoking in common areas, what can I do?

Report smoking in common areas to your property manager or board of directors.  Under the Smoke-Free Ontario Act, the board has a responsibility to:

  • Ensure that everyone is aware that smoking is prohibited in common areas;
  • Remove ashtrays and any object that serves as one;
  • Ensure that no one smokes in the common areas of these residences;
  • Post “no-smoking” signs at all entrances, exits, washrooms, and other appropriate locations.

Local public health units will carry out inspections and investigate complaints in multi-unit dwellings in order to enforce the Act. If you live in a municipality with a bylaw that prohibits smoking within a certain distance of doorways, operable windows and/or air intakes, your board is responsible for keeping these areas smoke-free as well.

Click here for a list of municipalities with bylaws stronger than the Smoke-Free Ontario Act.

Do non-smoking co-op members have a right to clean air?

Not exactly. There is no “right to clean air” enshrined anywhere in Canadian law.

In the absence of a no-smoking policy, co-op members can try seeking relief from involuntary exposure to second-hand smoke using the corporation’s general bylaws pertaining to nuisance or reasonable enjoyment (if they exist). Nuisance has a particular meaning in law–it is an unreasonable interference with the use and enjoyment of property. The appropriate test to determine whether there is an actionable nuisance involves a balancing between the plaintiff’s interest and the defendant’s interest. To prove nuisance it is not necessary to prove the intent, negligence or fault of the person causing the nuisance.

However, whether or not a co-op’s board of directors would recognize second-hand smoke as a nuisance will very much depend upon the exact wording of the bylaw relating to nuisance. Very often the nuisance rule, while including general language, is part of a specific issue such as fire hazards or noise. Whether or not nuisance exists which is covered by a nuisance bylaw is many times specifically left to the discretion of the co-op’s board of directors to determine.

Do members who smoke have an unrestricted right to smoke in their units, even if their second-hand smoke bothers other members?

No. There is no such thing as “the right to smoke.” However, in the absence of a specific no-smoking bylaw, members do have a right to smoke in their units.

However, it should be stressed that this right is not absolute and is limited by other people’s right to enjoy their property. While a unit owner who smokes chooses to accept the known risks associated with smoking, he or she doesn’t have the right to require others in the building to share those risks.

If there is evidence that second-hand smoke is infiltrating your home from a neighbouring unit or balcony on a frequent and on-going basis, and is substantially interfering with your use and enjoyment of your home, then you can either approach the co-op’s board of directors, your neighbour who smokes, or both. See do the groundwork for more information.

If you have a health condition made worse by exposure to second-hand smoke, you might want to consider filing a human rights application citing discrimination based on disability.

Download our article on Human Rights and No-Smoking Policies for Multi-Unit Dwellings.

If my neighbour’s smoke is infiltrating my unit or balcony, what can I do

See our section called address second-hand smoke.

Can my co-op legally adopt a no-smoking bylaw for private suites and balconies?

Yes. It is perfectly legal for a housing co-operative to have a no-smoking bylaw, provided that it is confirmed by at least a two-thirds vote of the co-operative’s members. See our legal opinion section for more information, along with our resource Smoke-free Housing Co-operatives.

Can air filters, purifiers or ventilation clear the air of the toxins in second-hand smoke?

Air filters, purifiers and ventilation systems cannot eliminate second-hand smoke, nor can they address the health concerns of exposure to second-hand smoke. Some of the smoke and larger particles from the air may be removed, but they will not remove the smaller particles or gases found in second-hand smoke.

The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE), the world’s leading association on indoor air quality standards, asserts that there is no acceptable ventilation system that can protect the health of individuals exposed to second-hand smoke.

James Repace, an internationally recognized second-hand smoke physicist, conducted a review for ASHRAE on controlling tobacco smoke. He concluded that, “ventilation technology cannot possibly achieve acceptable indoor air quality in the presence of smoking, leaving smoking bans as the only alternative.”

Read what Health Canada has to say about second-hand smoke and air filters, purifiers and ventilation.

Are there smoke-free housing co-ops in Ontario?

The Conservation Co-op in Ottawa passed a bylaw that came into effect January 1st, 2013. And based on the calls we regularly receive, we know there is demand for smoke-free housing co-ops.

You have a role to play in terms of telling your board of directors, friends, neighbours and family that it can be done. Tell your board that you would prefer a smoke-free building where smoking is banned in all units and on outdoor balconies and patios. If people don’t know that there is demand for smoke-free housing, there will continue to be a lack of smoke-free options.

Check out our Smoke-free Housing Dirctory In the meantime, if you know of a smoke-free housing co-op, contact us.

Is there support for people who want to quit?

Absolutely. There’s support for anyone who wants to quit.

A great place to get started is the toll-free Smokers’ Helpline at 1.877.513.5333. You can also visit the Smokers’ Helpline online at

For more information, go to our cessation section.

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