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 apartment 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 the apartments on the windward side of the building, and flow across the common corridors to the apartments on the leeward side of the building; and
  • Mechanical ventilation systems will also cause the transfer of air to and out of your

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 apartment buildings?

Yes. Under the provincial Smoke-Free Ontario Act, smoking is prohibited in the common areas of public places (which includes your apartment building) including the corridors, elevators, laundry rooms, 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 smoke-free laws database for more information.

Municipalities involved in the provision of social housing have the jurisdiction to adopt policies prohibiting smoking in private units. For example, the Region of Waterloo passed such a policy that has been in effect since April 2010. Check out our smoke-free housing directory

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

Tell your landlord. Under the Smoke-Free Ontario Act, landlords have 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.

The Ministry of Health Promotion reports that local public health units will carry out inspections and investigate complaints in apartments, condominiums and college and university campuses 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 landlord is responsible for keeping these areas smoke-free as well.

To learn more about smoke-free bylaws, visit the Non-Smokers’ Rights Association online smoke-free laws database.

Do non-smoking tenants have a right to clean air?

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

However, the Residential Tenancies Act, 2006 states that tenants have a right to
reasonable enjoyment of their premises, which includes the right to be free from unreasonable disturbances. This could include being free from breathing toxic substances such as second-hand smoke on a frequent and on-going basis.

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

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

It should be stressed that this right is not absolute, and is limited by other people’s right to reasonable enjoyment of their units. While a tenant 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 your landlord has a responsibility to take steps to correct the problem.

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

Check out our resource called When Neighbours Smoke: A Tenant’s Guide.

It is important to talk to your landlord about the problem of second-hand smoke. However, it is equally important to try to minimize the problem yourself by taking steps such as talking to the smoking tenant, trying to block or seal your apartment where you think the smoke is entering, and working with your landlord to negotiate a solution.

If all your efforts fail to minimize the smoke, and your landlord has not taken reasonable steps to resolve the problem, you can apply to the Landlord and Tenant Board for an order requiring the landlord to provide reasonable enjoyment and/or compensate you for your loss of it. However, there is no guarantee that you will be successful. (See our taking action section for further information.)

Unfortunately, at the Landlord and Tenant Board there are no policy guidelines for adjudicators to follow regarding second-hand smoke and the loss of reasonable enjoyment. It is therefore unclear as to what evidence is required in order to meet the test of how much smoke constitutes an unreasonable disturbance.

To increase your chances of success, you will need to document the extent, severity and impact of the problem, and collect as much evidence as possible to prove your case. (See taking Action)

What is the landlord’s responsibility to address complaints of second-hand smoke, even if smoking is allowed in the building?

Under the Residential Tenancies Act, 2006 all tenants have the right to reasonable enjoyment of the rental unit, including the right to be free from unreasonable disturbances from other tenants. The landlord is responsible for ensuring that the tenant has reasonable enjoyment.

If smoke from a neighbouring unit is infiltrating your home, and is significantly impacting your health or how you are able to enjoy or use your unit, this can be considered a loss of your right to reasonable enjoyment. Addressing the issue of second-hand smoke is similar to addressing the issue of loud music. Playing music is allowed in private units, yet when it’s played too loudly and interferes with the reasonable enjoyment of other tenants, landlords have a responsibility to take steps to stop this intrusion, including last resort steps to end the tenancy. (See legal opinion.)

Can a landlord legally adopt a no-smoking policy in private suites and balconies?

Yes. Landlords have the right to include a no-smoking clause in all new tenancy agreements to ban smoking in individual units, outdoor balconies and patios or any area of the residential property.

However, under the Residential Tenancies Act, 2006 a landlord cannot change an existing tenancy agreement without the approval of the tenant. This means that tenants without a no-smoking clause in their tenancy agreement can continue to smoke in their units for the length of their tenancy.

Download How to implement a no-smoking policy: A protocol for rental housing.

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 rental buildings in Ontario?

Yes, but there is a critical shortage for Ontarians who want and need to live smoke-free. Many landlords think that no-smoking policies are illegal, discriminatory or unenforceable. Tenants are encouraged to tell landlords that they would prefer a smoke-free building where smoking is banned in all units and outdoor balconies and patios. If landlords don’t know that there is demand for smoke-free housing, there will continue to be a lack of smoke-free options.

We keep a directory of smoke-free housing (including those in transition). However, because the Residential Tenancies Act does not permit landlords to change the terms of existing tenants’ leases, many of these buildings are in transition and “grandfather” existing tenants who smoke. Make sure you ask lots of questions about a landlord’s no-smoking policy before you sign a lease, because you may well find that the building is not “smoke-free” even if a no-smoking policy is in place!

If you know of a smoke-free building, contact us.

How do I ensure that my next rental building is 100% smoke-free?

If you want to live in a 100% smoke-free building, ensure that there is a no-smoking clause written into your lease (or an attached addendum) that states the entire building is smoke-free, including the private units, and outdoor balconies and patios. It is not enough for the unit to be simply advertised as smoke-free, or for you to have seen this mentioned in an application form. You must sign a lease with the policy included.

When talking to potential landlords, here are some questions to ask about the no-smoking policy:

  • Does it apply to all tenants in the building?
    • If there are existing tenants who have been “grandfathered” (and are permitted to smoke), how many are grandfathered and where are they located?
  • How is the policy enforced?
  • Is there a designated smoking area on the property? If so, is it far enough away to ensure that smoke cannot travel into private units or balconies?
  • Did the previous tenant smoke in the unit you are considering? If so, what steps were taken to remove the odour and residue from walls, carpets and drapery?
Is there support for tenants 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 tools and resources.

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