Road traffic and air pollution

Learn about sources of traffic-related air pollution, its health effects and how to minimize your risk.

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What are the sources of traffic-related air pollution?

The main sources of traffic-related air pollution are:

  • cars
  • buses
  • transport trucks

When engines burn fuel (gasoline or diesel), air pollutants that can affect your health are emitted, such as:

Additional air pollution is created when some of the gasoline used by engines evaporates without being burned.

Traffic-related emissions also contribute to smog.

Exposure concerns

Most Canadians are exposed to air pollution from traffic on a daily basis while:

  • walking
  • riding in a vehicle
  • at home
  • standing along busy streets

Strict regulations have been introduced to decrease pollution and greenhouse gases from vehicles. These regulations have resulted in reduced emissions due to better:

  • engine performance
  • emission control technologies
  • fuel makeup, including fuels with low sulfur content

Although technology improvements have reduced vehicle emissions, there is still cause for concern because:

  • older trucks and cars remain in use
  • these vehicles emit more pollutants and greenhouse gases
  • vehicle numbers are high in densely populated urban areas
  • the total kilometres travelled by Canadian vehicles continues to increase

What are the health effects of traffic-related air pollution?

Air pollution from traffic has been linked to many negative health effects, including:

  • worsening asthma symptoms
  • asthma development in children
  • lung cancer
  • reduced lung function
  • heart disease
  • increased risk of death from heart conditions

Air pollution may worsen symptoms for people with existing heart and lung conditions.

Risks to young children

Children can be more sensitive to air pollution than people in other age groups. This is because children breathe in more air in relation to their body weight. This means that they breathe in more contaminants, so air pollution can affect them more.

The body's defence and lung systems are also not fully developed yet. Therefore, the health of young children may be more affected by air pollution.

Children living in areas with heavy traffic have a higher risk of having breathing problems than other children. Exposure to traffic pollution can worsen asthma in children and may increase the risk of asthma development.

Children can also be exposed to traffic pollution when commuting to and from school. To learn more about children's exposure to diesel exhaust from diesel school buses visit: School buses and diesel exhaust.

How can you minimize your risk?

You can minimize your risk of health effects from traffic-related air pollution by:

  • choosing low-traffic routes for:
    • cycling
    • walking
    • running
  • exercising in parks and green spaces, away from major roadways
  • reducing outdoor air pollution in your home by closing windows and using:
    • a ventilation system with filtration
    • air conditioning on very hot days
  • considering local traffic patterns and avoiding high-traffic areas when choosing a:
    • school
    • daycare
    • place to live
  • limiting time spent outdoors when pollution levels are high, especially for vulnerable groups, such as:
    • infants
    • children
    • diabetics
    • the elderly
    • those with heart or lung problems
  • avoiding idling your vehicle in an attached garage, and keeping any doors between your house and the garage closed

The Air Quality Health Index

The Air Quality Health Index (AQHI) can help you learn about local air pollution and its impact on your health. The AQHI measures the air quality in relation to your health on a scale from 1 to 10. It provides advice for making decisions to protect yourself and those in your care from the risks of air pollution.

Check the AQHI in your community regularly. If it is not yet available in your area, check your provincial environment ministry website for local air quality information.

Talk to your health care provider about other ways to protect your health when air pollution levels are high. This is especially important for people with heart and lung conditions.

Reducing traffic-related air pollution

You can help reduce pollution from traffic by:

  • choosing alternate ways to travel, such as:
    • walking or cycling
    • public transit
    • carpooling
  • driving at a steady speed and avoiding rapidly accelerating when possible
  • warming your engine with a block heater on cold days before starting it (emissions are higher when the engine is cold)
  • consulting the Fuel Consumption Ratings Search Tool before buying a vehicle
  • turning off your engine when stopped for more than 10 seconds, unless you are in traffic or at an intersection
  • reducing fuel consumption and emissions by:
    • maintaining your vehicle's engine
    • keeping your tires properly inflated as indicated by the manufacturer

For more information

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