Outdoor Air Pollution

On this page:

The outdoor air quality in Ottawa is almost always ideal for enjoying outdoor activities and poses a low risk even to people who are sensitive to air pollution. However, every day there are people and places that are impacted by local sources of air pollution. Simple actions like not idling your vehicle or having wood fires can make a big difference to our local air quality and those who are affected. Find out more below about what you are breathing today, who is most affected, what our biggest sources of local air pollution are, and what you can do to protect yourself and improve local air quality.

Monitor the Air Quality Health Index and the health messaging to plan activities accordingly.

Protect yourself from outdoor air pollution including wildfire smoke

Wildfire smoke

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 visiting the Government of Canada's Wildfire smoke, air quality and your health website.

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.


If you are living in an area where neighbours are burning wood and/or you live near very busy roadways, take action to protect your health. 

  • Reduce time outdoors when outdoor air pollution levels are high
    • Check the AQHI every day to find out regional air quality readings and forecasts for Ottawa.
    • Avoid strenuous outdoor work, exercise, and playtime.
    • Stay indoors in a cool, well-ventilated place and plan indoor activities for children.
    • If you must be outside, try to schedule your activities early in the morning when pollution levels are lowest.
    • If you experience symptoms such as tightness in your chest, wheezing, or shortness of breath, seek medical attention.
  • Avoid traffic-related air pollution
    • Schedule appointments and errands to avoid morning and evening rush hours.
    • Avoid high traffic roadways, even if you are in a vehicle, especially during rush hour. The further away you are from busy roads during exercise, the better. Exposure is reduced when you are at least 50 to 100 metres away.          
    • When walking, taking a side street instead of a busy road can reduce your exposure to air pollution by up to 60%. 
    • If possible and safe, walk on the side of the road that is upwind of the traffic.  
    • Seek quieter roadways when exercising.
  • Reduce infiltration of outdoor air pollutants into your home. Health Canada suggests:
    • Keep windows and doors closed, and use air conditioning, if required.
    • Properly seal windows and doors with weather stripping.
    • Set your ventilation system to recirculate when the outdoor air is poor and bring in fresh air when the outdoor air has improved.
    • Install a high-quality high-efficiency particulate air filter.

Back to the top

Today’s air quality in Ottawa

Check the current and forecasted air quality and detailed outdoor air pollutant levels for the City of Ottawa to find out the overall Ottawa air quality today. The Air Quality Health Index (AQHI) is a scale that describes regional air quality and what it means to your health. It looks at the most prevalent air pollutants and grades them on a weighted basis to produce a number on a scale from 1 to 10+ that shows the relative health risk associated with the air pollution level in a community. The higher the value of the Air Quality Health Index, the more likely people will experience symptoms associated with poor air quality. Find out more about the AQHI and how it can be used to plan outdoor activities.  

AQHI Video – What are you breathing today? 

Back to the top

Health effects associated with air pollution

Air pollutants can be harmful if we are exposed to high levels, especially over long periods of time, so it is important to be aware of where air pollution comes from and limit your exposure whenever possible. The higher the level of pollution, the longer a person is exposed, and the phase of life during which your exposure takes place will determine how impactful it may be. People at highest risk to poor outdoor air quality include older adults; pregnant people; infants and young children; people who work or exercise strenuously outdoors; and those with pre-existing (diagnosed or un-diagnosed) health conditions including, cancer, diabetes, mental illness, and lung or heart conditions. 

In the short term, episodes of poor air quality are known to increase respiratory and cardiovascular hospital admissions and deaths. In the long term, episodes of poor air quality can reduce life expectancy. Health Canada describes the short- and long-term health effects people may experience that are associated with outdoor air pollutants, including: 

Short-term health symptoms (in people who are otherwise healthy):

Tiredness, headache, dizziness, coughing and sneezing, wheezing or difficulty breathing, more mucous in the nose or throat, and dry or irritated eyes, nose, throat, or skin.

Short-term health symptoms in people with existing illnesses (both diagnosed and un-diagnosed):

  • People with asthma or COPD may notice an increase in cough, wheezing, shortness of breath or phlegm. 
  • People with heart failure may experience increased shortness of breath or swelling in the ankles and feet. 
  • People with heart rhythm problems may notice increased fluttering in the chest or feeling light-headed. 
  • People with angina or coronary artery disease may have an increase in chest or arm pain.

Long-term health effects 

Long term health effects that are associated with prolonged exposure to elevated levels of air pollution include:

  • Stroke and heart conditions such as arrhythmia or heart attack
  • allergies
  • cancer, including childhood leukemia, adult lung cancer
  • lung conditions such as chronic obstructive pulmonary disease (COPD), asthma (children are particularly at risk of developing asthma symptoms), and premature death

Back to the top

Local sources of air pollution – residential wood burning and traffic

The two main sources of outdoor air pollution in Ottawa come from residential wood burning and traffic-related air pollution, including idling vehicles. A 2021 report from Health Canada on the Health Impacts of Air Pollution in Canada: Estimates of morbidity and premature mortality outcomes found these two sectors contribute the most to air pollution-related Canadian premature deaths, with home firewood burning associated with 2,300 deaths and on-road transportation associated with 1,200 deaths in 2015. Occasionally transboundary pollutants from other regions, such as smog and wildfire smoke, are carried into Ottawa from further away when weather conditions are right. 

Smog is a mixture of air pollutants that is formed in the presence of sunlight as emissions released from vehicles, industrial sources and human activities mix with contaminants already present in the air. Smog can blanket urban, suburban, and rural areas, making it a health risk for all residents of Ottawa.

The largest volume of pollutants generated from these sources that are harmful to humans are small particulate matter (PM2.5), nitrogen dioxide (NO2), and ground level ozone (O3). Measurements of these three pollutants form the hourly AQHI readings that describe the regional outdoor air pollution in Ottawa.  

Residential wood burning

Wood burning creates harmful air pollution both indoors and outdoors, and it is not considered to be a healthy home heating option because it is the largest air pollutant source contributing to premature deaths in Canada and Ontario. Most wood burning devices release large numbers of small particles into the air.  These very small particles can remain suspended in the air for many days, travelling up to 100 km from where they originate.

Wood smoke affects both outdoor and indoor air quality because it can easily penetrate or be drawn indoors where it can build up inside the home. We spend up to 85 per cent of our time indoors, especially in the winter months, so it is important that both our indoor and outdoor air is healthy.

Although many people enjoy the smell of wood burning, the smoke contains chemicals and contaminants that are not healthy for us or for our environment. There are many components of wood smoke emissions that can affect our health including small particulate matter, carbon monoxide and polycyclic aromatic hydrocarbons (PAHs). 

Traffic-related air pollution (TRAP)

Higher levels of air pollution are found on and near major roads and highways. Most local air pollution in Ottawa is caused by traffic, especially during and after rush hour. The best way to understand the levels of air pollution near you is to know how close you are to a major roadway or highway. The closer you are to the roadway and the more traffic there is, the higher the air pollution levels. The AQHI readings in Ottawa are not intended to measure air quality at specific locations and cannot be used to determine exposure to air pollution associated with traffic. 

People who live or exercise outdoors less than 100 metres away from a major road or less than 500 meters from a highway are at increased risk of exposure to air pollution and its harmful health effects, including damage to our tissues and inflammation in our bodies. Small particles can be breathed deep into the lungs and carry pollutants directly into our bloodstream.

Back to the top

Climate change and greenhouse gas emissions

Climate change is primarily caused by the burning of fossil fuels like natural gas, oil, gasoline, and diesel to heat our buildings and fuel our vehicles. In many places around the globe, the fossil fuel coal is also used for heating, industry, and electricity production. Climate change impacts our health in the long term because it is causing warmer temperatures, and more extreme heat days, flooding, and extreme weather events in Ottawa. On April 24, 2019, City Council declared a Climate Emergency for the purposes of naming, framing, and deepening our commitment to protecting our economy, our ecosystems, and our community from climate change.   

Find out what the City of Ottawa is doing to characterize, reduce greenhouse gas emissions,, and increase our ability to adapt to our changing climate climate changes in the future, and how you can help:  

What you can do to reduce local air pollution

Everyone can do their part to keep Ottawa air safe for everyone to breathe. Consider the following ways to limit air pollution, and make a difference in your neighbourhood, the City, and even further: 

  • If you are not burning wood, do not start. If you do heat with wood, switch your heating source to one that does not involve burning wood if possible.
    • Find out more about minimizing wood smoke
    • Choose a high efficiency wood stove that has low emissions.
    • Maintain your wood stove, clean your chimney, and burn hot fires that produce less smoke.
    • Avoid burning wood on days when the Air Quality Health Index (AQHI) is high or when weather conditions prevent air pollutants from dispersing.  
    • Burn only clean, dry and well-seasoned wood and newsprint.  Never burn garbage and products such as cardboard, which contains chemicals that end up in our lungs.
    • Keep fires small and hot. Smouldering fires create more smoke.
    • Install smoke alarms and a carbon monoxide detector in your home.
  • Reduce the use of fossil fueled vehicles and equipment.
    • Find active ways to commute to work, get together with others, and get errands done
    • Use public transit for all kinds of trips. Plan your trips
    • Consider electric or hybrid/hybrid plug-in vehicles when upgrading personal vehicles and when purchasing home maintenance tools such as lawnmowers. 
    • Choose to live in a community that is walkable, compact, connected to amenities, and has lots of greenspace and trees. Advocate for these features if they do not already exist.
    • Do not idle your vehicle. Leave your home prepared for the weather so you do not need to use your vehicle to keep you warm during the winter or cool during the summer. Visit the City of Ottawa web page on Reducing idling in Ottawa.
    • Try to plan trips to avoid driving in traffic congested areas, especially during rush hour.   
    • Consider purchasing a smaller or light-weight vehicle that uses less fuel.
    • Maintain your vehicles, check your oil, and tire pressure regularly.
  • Conserve energy. Homes and buildings produce almost half of the greenhouse gas emissions in Ottawa today. An energy-efficient home is healthier to live in, more resilient, more climate-friendly, and reduces both money spent on energy and energy used.
    • Use a smart thermostat to set your home or office indoor temperature with adjustments for when you are away or sleeping. A good guide is to program 17°C when you are sleeping or not at home, and 20°C when you are awake and at home.
    • Consider getting a home energy assessment to learn about other ways to reduce energy use and greenhouse gas emissions. 
    • Consider switching to electric home heating and cooking equipment to reduce combustion of fossil fuels inside the home. 
  • Visit Better Homes Ottawa for more information on conserving energy and reducing green house gas emissions 

Create healthy built environments

Advocate for healthy built environments and communities that are walkable, compact, connected to amenities, and have lots of greenspaces and trees. Find out more about how you can help make your community healthier in this video:

Share this video Twitter Logo Facebook logo Email share icon


Back to the top

Contact Us