Air quality

Dangerous weeds

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Visit our climate change frequently asked questions page

Climate change is closely linked to air quality. Climate change is affecting air quality in Canada, and several air pollutants contribute to climate change.

A warming climate is expected to worsen air quality levels. Climate change will:

  • Increase the frequency and severity of wildfires
    • Wildfire season typically runs from early April to late October
    • Wildfire smoke is one of the most significant climate-related risks to air quality in Canada
  • Affect airborne allergens such as pollen by:
    • Increasing pollen counts
    • Extending pollen seasons
    • Expanding the geographic distribution of plant species

Climate change can also affect indoor air quality when:

  • High levels of outdoor air pollutants get into buildings
  • Mould grows following extreme weather events, such as floods

Make sure to check local Air Quality Health Index (AQHI). The Air Quality Health Index is a scale from 1 to 10+ designed to help you understand what the air quality around you means to your health. The higher the number, the greater the health risk associated with the air quality.

Summary of air quality health messages by category

Health risk:

  • Low risk

At risk population:

  • Enjoy your usual outdoor activities.

General population:

  • Ideal air quality for outdoor activities.

Health risk:

  • Moderate risk

At risk population:

  • Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms.

General population:

  • No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.

Health risk:

  • High risk

At risk population:

  • Reduce or reschedule strenuous activities outdoors. Children and the elderly should also take it easy.

General population:

  • Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.

Health risk:

  • Very high risk

At risk population:

  • Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion.

General population:

  • Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.

Health impacts

Exposure to air pollution increases the risk of health problems. Wildfire smoke can cause a variety of symptoms or health effects that can range in severity. Some symptoms or health effects are more common than others.

Milder and more common symptoms of smoke exposure include:

  • Headaches
  • Mild cough
  • Production of mucus
  • Nose, throat, eye and sinus irritation

In many cases, you can manage these symptoms without medical intervention.

More serious but less common symptoms of smoke exposure include:

  • Dizziness
  • Wheezing
  • Chest pains
  • Severe cough
  • Asthma attacks
  • Shortness of breath
  • Heart palpitations (irregular heartbeat)

If you experience any of these symptoms, talk to a health-care provider or seek urgent medical attention.

Who is at risk?

Everyone is at risk for health impacts related to poor air quality; however, health risks are greatest for: young infants and children, older adults, those living in high air pollution areas, people living with chronic illnesses (such as asthma, diabetes, heart or lung diseases), people who are pregnant, people who are underhoused or experiencing homelessness, people who work outdoors, or people participating in strenuous sports and outdoor activities.

Staying safe

If you are living in an area affected by wildfire smoke, you can learn about wildfire smoke events, the effects of wildfire smoke on your health, and how to protect yourself, by viewing the Wildfire smoke, air quality and your health page on the Government of Canada’s website.

Be prepared. Learn more about what to do before, during and after a wildfire.

Southeast Public Health recommends taking the following actions:

  • Stop or reduce your activity level if breathing becomes uncomfortable or you or someone in your care feels unwell. Please contact your health-care provider if you develop severe symptoms
  • Be sure to check on people in your care and those around you who may be more susceptible to smoke
  • Check the Air Quality Health Index (AQHI) and monitor your symptoms. Drinking lots of water can help your body cope with the smoke
  • If you have an HVAC system in your home, use the highest rated MERV filter for your system (ideally rated 13 or higher) and set the fan to recirculate air constantly. You can also use a portable High Efficiency Particulate Air (HEPA) air cleaner. Keep your doors and windows closed if the temperature in your home is comfortable. You can also take a break from the smoke at a local clean air location
  • Reduce sources of indoor air pollution. If you can, avoid smoking or vaping indoors, burning incense and candles, frying foods, using wood stoves and vacuuming. Dust on indoor surfaces can be removed by wiping and wet mopping during a pollution episode
  • If you must spend time outdoors, a well-fitted respirator type mask (such as a NIOSH certified N95 or equivalent respirator) that does not allow air to pass through small openings between the mask and face, can help reduce your exposure to the fine particles in smoke. These fine particles generally pose the greatest risk to health. However, respirators do not reduce exposure to the gases in wildfire smoke. It is important to listen to your body and reduce or stop activities if you are experiencing symptoms

Creosote and health information

Creosote is a general term for different oily liquids, with the most common variant being coal-tar creosote which is used as a heavy-duty wood preservative to protect rail ties against fungi, insects and other pests. It contains a number of chemicals, including VOCs that can vaporize and travel through the air.

Health effects from inhalation exposure over a period of several months can include irritation of the nose and throat, respiratory irritation (cough, shortness of breath), and other effects (headache, nausea, light-headedness). Children, pregnant people, and the elderly may be at higher risk of developing health effects following prolonged exposure. These health effects are expected to resolve once the exposure stops (the creosote is removed, or the person leaves the area). Although creosote exposure can also increase the risk of other health effects (for example, skin contact can cause sun sensitivity and sores; ingestion can cause organ damage), these effects would not be expected from inhalation exposures. Long-term, permanent health effects and increased risk of cancer are linked only to exposures occurring over a period of several years.

The following measures may help to reduce potential exposure:

  • Close windows to reduce outdoor air entering into your home.
  • If your home’s ventilation system has a filter, follow the manufacturer’s instructions regarding what filters are to be used and how frequently they are to be changed. Increase the ventilation rate and use a filter that can remove VOCs (for example, activated carbon), if possible.
  • Use a portable air purifier with a HEPA and activated carbon filter, if available.
  • Avoid spending long periods of time outside when you smell an odour of creosote.
  • To reduce your overall exposures to VOCs in the home, avoid smoking in the home and delay using paints, paint strippers, and other sources of VOCs until the ties are removed.
  • Report any symptoms or health concerns to your health-care provider.

Trichloroethylene

Trichloroethylene is a clear liquid synthetic chemical that evaporates easily. It is used for degreasing metal equipment, to make refrigerants and in commercial dry cleaners as a spot remover. Trichloroethylene is also a common ingredient in household products such as cleaning products, paint removers, spray adhesives, glues and paints.

Trichloroethylene is found in air, water and soil in locations where is it manufactured or used. Trichloroethylene breaks down very slowly in the environment and can accumulate in soil and groundwater. In the general population people can be exposed to Trichloroethylene through indoor air and drinking water. Occupational exposure for those that work with Trichloroethylene can occur through inhaling comminated air or absorbing Trichloroethylene though their skin.

Short term exposure (for example, minutes to days) to very high levels of Trichloroethylene can cause symptoms such as drowsiness, decreased memory and perception, visual effects and anesthesia. Long term exposure (for example, years) is suggestive of an increased risk of cancer.

People should avoid drinking water contaminated with Trichloroethylene and reduce time spent in areas with known high Trichloroethylene indoor air concentrations. Children should avoid playing in areas where Trichloroethylene has been found in soil. Consumers should always follow chemical product labels to minimize exposure to Trichloroethylene.

Other Trichloroethylene resources

Frequently asked questions

The best ways to reduce exposure to poor outdoor air quality or wildfire smoke is to prepare your home. Here are some tips to help:

  • Properly seal windows and doors
  • Consider purchasing one or more certified, properly-sized portable air purifiers
  • Reduce other sources of indoor air pollution such as cigarette smoke and take steps to improve air quality in your home
  • Keep windows and doors closed as much as possible. When there is an extreme heat event occurring with poor air quality, prioritize keeping cool
  • Change the filters of your ventilation system and portable air cleaner regularly during wildfire smoke events. Clogged filters are not effective at removing smoke

Workplaces

Know the signs and symptoms of poor air quality and wildfire smoke.

If you need to work outdoors, check with your provincial occupational health and safety associations.

Resources

Employers can learn more on our climate change and frequently asked questions page.