Air Quality Health Index publications

Air pollution: what are diesel and gasoline exhaust?

This infographic is a quick reference to show the relationship between air pollution, diesel and gasoline exhaust. Available in English and French.

See below for infographic text (HTML) or download the PDF (1247 KB)

Poster text: click for details

Air Pollution: What are Diesel and Gasoline Exhaust?

Diesel and gasoline exhaust are mixtures of gases, particles, and many different chemicals. Some of the pollutants in diesel and gasoline exhaust that impact human health include nitrogen dioxide (NO2), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs). The make-up of diesel and gasoline exhaust is variable depending on fuel type, engine type, and operating conditions.

Where do Diesel and Gasoline Exhaust come from?

Any vehicle or engine that uses diesel fuel produces diesel exhaust and any vehicle or engine that uses gasoline fuel produces gasoline exhaust. For vehicles and engines, exhaust is released from the tailpipe or muffler. Some examples of vehicles and engines that use diesel fuel or gasoline fuel include:

Mainly Diesel Fuel

  • Transport trucks
  •  Buses
  •  Ships
  • Trains
  • Generators
  • Heavy Equipment
    • Construction
    • Mining
    •  Agriculture

Mainly Gasoline Fuel

  • Cars, trucks, and motorcycles
  • Boats
  • Lawnmowers­
  • Chainsaws
  • Snowmobiles
  • All-terrain vehicles (ATVs)
  • Jet skis

Did You Know? Of all cars, trucks, and buses used in Canada, approximately 92% use gasoline and only 8% use diesel. However, diesel vehicles contribute to greater than 50% of some key air pollutant emissions from all on-road vehicles in Canada.

How are Canadians exposed to Diesel and Gasoline Exhaust?

People’s exposures to diesel and gasoline exhaust are variable depending on:

  • Mode of transportation (e.g. vehicle, bus, train, boat) and time spent in transit
  • Time spent outside close to roadways
  • Heavy traffic (e.g. major roads and highways) close to their home, school, and workplace
  • Being close to transport hubs, including bus or train stations and marine ports
  • Being close to or using diesel- or gasoline-powered equipment
  • Weather conditions (e.g. temperature, wind, precipitation)

 

What are the health effects of Diesel and Gasoline Exhaust?

Emissions from diesel- and gasoline-powered vehicles and equipment are major sources of air pollutants in Canada, especially in large cities. The health effects of air pollutants from diesel and gasoline exhaust include:

  • Increased asthma symptoms
  • Increased allergy symptoms
  • Increased lung problems
  • Increased heart problems
  • Increased hospital admissions
  • Increased medical visits
  • Lung cancer
  • Premature death

 

What Action is the Government of Canada taking on air pollution from Diesel and Gasoline Exhaust?

Increasingly more stringent federal regulations have been introduced over time to reduce air pollutant emissions from diesel- and gasoline-powered vehicles and equipment. Reductions in emissions, from these regulations, are mainly due to:

  • Improved engine performance
  • Adoption of the latest emission control technologies
  • Cleaner fuels, including fuels with low sulphur content

 

How can I protect myself from Diesel and Gasoline Exhaust and air pollution in general?

Ways to reduce exposure:

  • Avoid or reduce exercising near heavy traffic, especially during rush hour
  • Choose low-traffic routes for walking, running, or cycling
  • Exercise in parks and green spaces, away from major roadways
  • Avoid or reduce strenuous outdoor activities when air pollution levels are higher

 

Know the best times to be active outdoors:

  • Check the Air Quality Health Index in your community (airhealth.ca)
  • If you have a heart or lung condition, talk to your health care professional about additional ways to protect your health when air pollution levels are higher

 

Did you know? You can help to reduce diesel and gasoline exhaust emissions by:

  • Choosing alternate ways to travel, such as walking or cycling, public transit, or carpooling
  • Avoiding unnecessary idling of your vehicle
  • Maintaining your vehicles and equipment for optimal engine performance

For more information on air pollution, please visit https://www.canada.ca/en/health-canada/services/air-quality.html or contact us at: HC.air.SC@canada.ca

Air pollution: what is nitrogen dioxide?

This infographic is a quick reference to show the relationship between air pollution and nitrogen dioxode. Available in English and French.

See below for infographic text (HTML) or download the PDF (176 KB)

Poster text: click for details

Air pollution: what is nitrogen dioxide?

Nitrogen dioxide (NO2) is one of a group of gases known as nitrogen oxides (NOX). NO2 has direct health effects but can also react with other pollutants in air to form ground-level ozone (O3) and particulate matter (PM), the major components of smog. NO2 also contributes to the formation of acid rain.

Where do nitrogen oxides come from?

NOX comes mainly emitted from combustion, with the majority originating from man-made sources. Main sources of outdoor NOX are (but not limited to):

  • Vehicle emissions
  • Transportation of goods
  • Trains
  • Airplanes
  • Ships
  • Airplanes
  • Electricity generation
  • Oil and gas industry
  • Construction


Levels of nitrogen dioxide in outdoor air

Levels of NO2 in outdoor air are higher in cities, especially near areas of heavy traffic, and are lower in smaller communities and in rural areas. Levels of NO2 are also higher near some industries. More information can be found on the STATE OF THE AIR website (http://airquality-qualitedelair.ccme.ca/en/)

Health Effects of Nitrogen Dioxide

Health effects of outdoor NO2 can occur even at very low concentrations, including:

  • Increased lung problems
  • Increased hospital admissions
  • Increased medical visits
  • Premature death

Who is most at risk from air pollution?

Even healthy young adults can experience health issues on days when the air is heavily polluted but some groups are more at risk:

  • Children
  • Seniors
  • People with asthma, chronic obstructive pulmonary disease (COPD), cardiovascular diseases, diabetes
  • Active people of all ages who exercise or work hard outdoors

How Can I Protect Myself from Air Pollution?

Know the best times to be active outside:

  • Check the Air Quality Health Index in your community (airhealth.ca)
  • If you have a heart or lung condition, talk to your health care professional about additional ways to protect your health when air pollution levels are higher

Ways to reduce exposure:

  • Avoid or reduce strenuous outdoor activities when air pollution levels are higher
  • Avoid or reduce exercising near heavy traffic, especially during rush hour

What action is the Government of Canada taking on nitrogen dioxide?

  • Federal regulations have reduced outdoor NO2 emissions in Canada from key sources.
  • Canada has agreed to international treaties to reduce NO2 emissions from outdoor sources.
  • Canada has established the Canadian Ambient Air Quality Standards (CAAQS). These are health- and environment-based numerical values of outdoor air concentrations of pollutants intended to drive continuous air quality improvement in Canada. The CAAQS, a key element of the Air Quality Management System, were developed through a process steered by the Canadian Council of Ministers of the Environment (CCME).
CAAQS numerical values
Pollutant Averaging time Effective in 2020 Effective in 2025 Units Metric
NO2 1 hours 60 42
Parts per billion (ppb) The 3-year average of the annual 98th percentile of the daily maximum 1-hour average concentrations
Annual (1 year) 17.0 12.0 The average over a single calendae year of  all the 1-hour average concentrations

For more information on air pollution, please visit https://www.canada.ca/en/health-canada/services/air-quality.html or contact us at: HC.air.SC@canada.ca

Air pollution: what is ozone?

This infographic is a quick reference to show the relationship between air pollution and ozone. Available in English and French.

See below for infographic text (HTML) or download the PDF (1199 KB)

Poster text: click for details

Air pollution: what is ozone?

Ground-level ozone (O3) is a gas that forms close to the Earth’s surface through reactions between certain pollutants (known as precursors) in the presence of sunlight. Ozone is a component of smog.

Where do ozone precursors come from?

Ozone precursors, such as nitrogen oxides (NOx) and volatile organic compounds (VOCs), can come from man-made or natural sources including (but not limited to):

  • Vehicle emissions
  • Industry
  • Wood burning
  • Forest fires
  • Agriculture
  • Construction

Levels of ozone in outdoor air

There are variations in levels of ozone in outdoor air by season and region. In general, higher levels of ambient ozone occur in spring and summer, and lower levels in winter. During summer, ozone levels peak between noon and 6 pm. More information can be found on the State of the air website (http://airquality-qualitedelair.ccme.ca/en/)

Health effects of ozone

Health effects of ozone can occur even at very low concentrations, including:

  • Increased lung problems
  • Increased hospital admissions
  • Increased medical visits
  • Premature death

Who is most at risk to air pollution?

Even healthy young adults can experience health issues on days when the air is heavily polluted but some groups are more at risk:

  • Children
  • Seniors
  • People with asthma, chronic obstructive pulmonary disease (COPD), cardiovascular diseases, diabetes
  • Active people of all age who exercise or work hard outdoors

How can I protect myself from air pollution?

Know when the air is unhealthy:

  • Check the Air Quality Health Index in your community to find out the best time to be active outside (airhealth.ca)
  • If you have a heart or lung condition, talk to your health care professional about additional ways to protect your health when air pollution levels are high

Ways to reduce exposure:

  • Avoid or reduce strenuous outdoor activities when air pollution levels are high
  • Avoid or reduce exercising during smog episodes

What action is the Government of Canada taking on ozone?

  • Federal regulations have reduced emissions of ozone precursors from key sources in Canada.
  • Canada has agreed to international treaties to reduce transboundary flow of ozone and its precursors.
  • Canada has established the Canadian Ambient Air Quality Standards (CAAQS). These are health- and environment-based numerical values of outdoor air concentrations of pollutants intended to drive continuous air quality improvement in Canada. The CAAQS, a key element of the Air Quality Management System, were developed through a process steered by the Canadian Council of Ministers of the Environment (CCME).
CAAQS numerical values
Pollutant Averaging time Effective in 2015 Effective in 2020 Units Metric
Ozone 8 hours 63 62 Parts per billion (ppb) The 3-year average of the annual 4th highest daily maximum 8-hour average concentrations

For more information on air pollution, please visit https://www.canada.ca/en/health-canada/services/air-quality.html or contact us at: HC.air.SC@canada.ca

Air pollution: what is particulate matter (PM)?

This infographic is a quick reference to show the relationship between air pollution and particulate matter. Available in English and French.

See below for infographic text (HTML) or download the PDF (1304 KB)

Poster text: click for details

Air pollution: what is particulate matter (PM)?

PM is a mixture of small liquid and solid particles in the air we breathe. They vary in size and chemical make-up. PM is a component of smog.


Where does PM come from?

PM can come directly from man-made and natural sources or be formed by reactions among other pollutants. Main sources of PM are (but not limited to):

  • Vehicle emissions
  • Industry
  • Wood burning
  • Forest fires
  • Agriculture
  • Construction
  • Road dust


Levels of PM in outdoor air

Levels of PM in outdoor air can vary by region and by season.  More information can be found on the STATE OF THE AIR website (http://airquality-qualitedelair.ccme.ca/en/)

Health Effects of Particulate Matter

Health effects of PM can occur even at very low concentrations, including:

  • Increased heart problems
  • Increased lung problems
  • Increased hospital admissions
  • Increased medical visits
  • Lung cancer
  • Premature death

Who is most at risk from air pollution?

Even healthy young adults can experience health issues on days when the air is heavily polluted but some groups are more at risk:

  • Children
  • Seniors
  • People with asthma, chronic obstructive pulmonary disease (COPD), cardiovascular diseases, diabetes
  • Active people of all ages who exercise or work hard outdoors

How Can I Protect Myself from Air Pollution?

Know the best times to be active outside:

  • Check the Air Quality Health Index in your community to find out the best time to be active outside (airhealth.ca)
  • If you have a heart or lung condition, talk to your health care professional about additional ways to protect your health when air pollution levels are high

Ways to reduce exposure:

  • Avoid or reduce strenuous outdoor activities when air pollution levels are higher
  • Avoid or reduce exercising near heavy traffic, especially during rush hour

What action is the Government of Canada taking on PM?

  • Federal regulations have reduced PM emissions in Canada from key sources.
  • Canada has agreed to international treaties to reduce PM emissions.
  • Canada has established the Canadian Ambient Air Quality Standards (CAAQS). These are health- and environment-based numerical values of outdoor air concentrations of pollutants intended to drive continuous air quality improvement in Canada. The CAAQS, a key element of the Air Quality Management System, were developed through a process steered by the Canadian Council of Ministers of the Environment (CCME).
CAAQS numerical values
Pollutant Averaging time Effective in 2015 Effective in 2020 Units Metric
PM2.5 24 hours (calendar day) 28
27
Micrograms per cubic metre (μg/m3) The 3-year average of the annual 98th percentile of the daily 24-hour average concentrations
Annual (calendar year) 10.0 8.8
The 3-year average of the annual average concentrations

For more information on air pollution, please visit https://www.canada.ca/en/health-canada/services/air-quality.html or contact us at: HC.air.SC@canada.ca

Air pollution: what is sulphur dioxide?

This infographic is a quick reference to show the relationship between air pollution and sulphur dioxide. Available in English and French.

See below for infographic text (HTML) or download the PDF (1183 KB)

Poster text: click for details

Air pollution: what is sulphur dioxide?

Sulphur dioxide (SO2) is one of a group of gases known as sulphur oxides (SOX).  SO2 has some direct health effects but is also an important chemical leading to the formation of particulate matter (PM), a component of smog. SO2 also contributes to the formation of acid rain.


Where do sulphur oxides come from?

SOX comes mainly from man-made sources, but can also come from natural sources. Main sources of SOX are (but not limited to):

  • Mining, smelting and refining of metal ores
  • Electricity generation from coal
  • Oil and gas industry
  • Ships
  • Airplanes
  • Volcanoes


Levels of sulphur dioxide in outdoor air

Levels of SO2 in outdoor air are higher in certain areas of Canada, such as communities close to some types of industrial facilities and in areas of oil and gas extraction. More information can be found on the STATE OF THE AIR website (http://airquality-qualitedelair.ccme.ca/en/)

Health Effects of sulphur dioxide

Health effects of SO2, especially for people with respiratory problems, include:

  • Increased lung problems
  • Increased hospital admissions
  • Increased medical visits

Who is most at risk from air pollution?

Even healthy young adults can experience health issues on days when the air is heavily polluted but some groups are more at risk:

  • Children
  • Seniors
  • People with asthma, chronic obstructive pulmonary disease (COPD), cardiovascular diseases, diabetes
  • Active people of all ages who exercise or work hard outdoors

How Can I Protect Myself from Air Pollution?

Know the best times to be active outside:

  • Check the Air Quality Health Index in your community (airhealth.ca)
  • If you have a heart or lung condition, talk to your health care professional about additional ways to protect your health when air pollution levels are higher

Ways to reduce exposure:

  • Avoid or reduce strenuous outdoor activities when air pollution levels are higher

What action is the Government of Canada taking on sulphur dioxide ?

  • Federal regulations have reduced SO2 emissions in Canada from key sources.
  • Canada has agreed to international treaties to reduce SO2 emissions.
  • Canada has established the Canadian Ambient Air Quality Standards (CAAQS). These are health- and environment-based numerical values of outdoor air concentrations of pollutants intended to drive continuous air quality improvement in Canada. The CAAQS, a key element of the Air Quality Management System, were developed through a process steered by the Canadian Council of Ministers of the Environment (CCME).
CAAQS numerical values
Pollutant Averaging time Effective in 2020 Effective in 2025 Units Metric
SO2 1 hour
70
65
Parts per billion (ppb) The 3-year average of the annual 99th percentile of the daily-maximum 1-hour average concentrations
Annual (1 year) 5.0
4.0
The average over a single calendar year of all the 1-hour average concentrations

For more information on air pollution, please visit https://www.canada.ca/en/health-canada/services/air-quality.html or contact us at: HC.air.SC@canada.ca

Air Quality Health Index Bookmark thumbnail

Bookmark

The bookmark includes the Air Quality Health Index scale and web address for further information. 

Available in English or French.  See below for bookmark text (HTML) or download the PDF (1649 KB).

Bookmark text. Click for details.

At Meteorological Service of Canada, we love to predict! The Air Quality Health Index forecast. For those you expect to love for a long time... Because we care, we forecast! www.ec.gc.ca/cas-aqhi

 

Air Quality Health Index Brochure thumbnail

Brochure

This 8 page self-standing table top brochure provides information on the impacts of air pollution on health, lists ways to protect your health, and explains how to use the Air Quality Health Index. It includes colorful images with information on the health risk for different Air Quality Health Index values, including advice for both the at-risk population and the general public. This brochure is particularly useful for Health Professionals or anyone looking to distribute and/or display information on the AQHI.

To order, contact publications@hc-sc.gc.ca. Available in English or French. See below for brochure text (HTML) or download the PDF (3068 KB). ISBN 978-1-100-54369-7.

Brochure text. Click for details.

Be air aware - Know the facts about air quality

Canada's natural environment offers many opportunities to enjoy healthy outdoor activities. Most Canadians don't need to change their plans to enjoy the great outdoors because of air pollution, but some people may need to reduce their risk by taking appropriate precautions.

Every year thousands of Canadians are admitted to hospital suffering from the effects of air pollution.

Individuals react differently to air pollution. Children, the elderly and those with heart or lung disease are most sensitive to the adverse health effects of air pollution. People with diabetes are also at greater risk because they are more prone to heart disease.

Even Canadians who are relatively fit and healthy can experience symptoms when exercising or working outdoors, if pollution levels are higher than usual.

What is air pollution?

There are many different types of air pollutants from a wide range of sources. The pollutants of greatest risk to health are the gases and particles that have been found to contribute to cardiovascular and respiratory disease. These pollutants are often lumped together under the term smog.

How does air pollution affect my health and the health of my family?

Depending on the length of time you are exposed, your health status, and the concentration of pollutants, air pollution can have a negative effect on your heart and lungs. It can:

  • Make it harder to breathe
  • Irritate your lungs and airways
  • Worsen chronic diseases such as heart disease, Chronic Obstructive Pulmonary Disease (COPD) and asthma
  • Children, the elderly and those with diabetes, heart or lung disease are most sensitive to the adverse health effects of air pollution

Negative health effects increase as air pollution worsens. Studies have shown that even modest increases in air pollution can contribute to more emergency room visits, hospital admissions and sometimes result in death. Small increases in air pollution over a short period of time can increase symptoms of pre-existing illness among those at risk.

How do I know if I am at risk?

People with diabetes, lung disease (COPD, asthma, lung cancer) or heart disease (such as angina, and a history of heart attacks) are more sensitive to air pollution.

Seniors are at higher risk because of weakening of the heart and lungs and an increased likelihood of health problems such as heart and lung disease.

Children are also more vulnerable to air pollution because they have a less-developed respiratory system. Because of their size, children inhale more air perkilogram of body weight than adults.

People participating in strenuous sports or work outdoors breathe more deeply and rapidly, allowing more air pollution to enter their lungs. They may experience symptoms like eye, nose or throat irritation, coughing or difficulty breathing when air pollution levels are high.

What is the Air Quality Health Index (AQHI)?

The Air Quality Health Index is a tool designed to help you understand what the quality of the air around you means to your health. It is a tool developed by health and environmental professionals to communicate the health risk posed by air pollution.

It is designed to help you make decisions to protect your health and the environment by:

  • Limiting short-term exposure to air pollution
  • Adjusting your activity during episodes of increased air pollution and encouraging physical activity on days when the index is lower
  • Reducing your personal contribution to air pollution

The index provides specific advice for people who are especially vulnerable to the effects of air pollution as well as for the general public.

How does it work?

The Air Quality Health Index (www.airhealth.ca) provides a number from 1 to 10+ to indicate the level of health risk associated with local air pollution. Occasionally, when the amount of air pollution is abnormally high, the number may exceed 10.

When the number is low, it's the ideal time for most people to enjoy their favourite outdoor activities.

The higher the number, the greater the health risk and your need to take precautions.

The index describes the level of health risk associated with this number as 'low', 'moderate', 'high' or 'very high', and suggests steps you can take to reduce your
exposure.

It also forecasts local air quality for today and tomorrow and provides associated health advice.

The index does not measure the effects of odour, pollen, dust, heat or humidity on your health.

How is the AQHI calculated?

The AQHI is designed as a guide to the risk presented by a mixture of common air pollutants which are known to harm human health. Three specific pollutants have been chosen as indicators of the overall mixture:

  1. Ground-level Ozone (O3) is formed by photo-chemical reactions in the atmosphere. Ozone can be transported long distances within a polluted air mass and can be responsible for large regional air pollution episodes.
  2. Particulate Matter is a mixture of tiny airborne particles that can be inhaled deep into the lungs. These particles can either be emitted directly by vehicles, industrial facilities or natural sources like forest fires, or formed indirectly as a result of chemical reactions among other pollutants.
  3. Nitrogen Dioxide (NO2) is released by motor vehicle emissions and power plants that rely on fossil fuels. It contributes to the formation of the other two pollutants. Nitrogen dioxide is often elevated in the vicinity of high traffic roadways and other local sources.

All three can have serious, combined effects on human health - from illness to hospitalization to premature death -- even as a result of short-term exposure. Significantly, all of these pollutants can pose health risks, even at low levels of exposure, especially among those with pre-existing health problems.

How to use the AQHI index

First, determine which group you are in:

At-risk Populations: people with existing heart or lung conditions, seniors, children or people participating in sports or strenuous work outdoors

OR:

General Population: otherwise healthy people, and those not exerting themselves outdoors.

  1. Check www.airhealth.ca or the Weather Network for your local AQHI information
  2. Read and follow actions recommended for your group
  3. Use the forecast to plan outdoor activities

 

AQHI Infographic thumbnail

Canada App Infographic  

This infographic helps you understand how to use the AQHI mobile app while on the go!  You will learn how to use the AQHI scale to “self-calibrate,” and to decide the best time to go outside. Available in English or French.

See below for infographic text (HTML) or download the PDF (790 KB).

Infographic text. Click for details.

Air Quality Health Index or AQHI

Higher AQHI number - Greater health risk - Protect your health

The AQHI is particularly useful for people who are sensitive to air pollution such as people with lung or heart conditions, young children and older adults.

Know your number ahead of time and plan the best time to be active outdoors.

Learn your number:

  1. Check the AQHI before you go outside
  2. Take note of the AQHI number when you start to notice you may be affected by air quality
  3. Use the AQHI forecast to plan your activities

Download the AQHI Canada App

Visit airhealth.ca to find the current air quality rating for your area.

 

Air Quality Health Index Classroom Kit Book I thumbnail

Classroom Kit Book I: Health

Educators can choose from six 30-minute learning centres for their grade 5 or 6 students, building skills in literacy, communication, reflection, and problem-solving. Developed directly from provincial and territorial curriculum documents, topics include: ways to prepare for and predict various weather and/or air quality conditions, how media, peers and family affect decisions, outdoor safety, and environmental health issues.

Available in English or French.  View or download the learning stations here HTML or PDF (3060 KB).

Air Quality Health Index Classroom Kit Book II thumbnail

Classroom Kit Book II: Environment

These lessons use comic strips, rotating placemats, and sticky concept maps to teach students about how electricity relates to air quality. They also connect everyday choices to renewable and non-renewable sources of energy.

Available in English or French. View or download the learning stations here HTML or PDF (6829 KB).

Air Quality Health Index Factsheet thumbnail

Fact Sheet

This two-page fact sheet provides information on the impacts of air pollution on health, lists ways to protect your health, and explains how to use the Air Quality Health Index. It includes a chart with information on the health risk for different Air Quality Health Index values, including advice for both the at-risk population and the general public.

To order, contact publications@hc-sc.gc.ca. Available in English or French.  See below for fact sheet text (HTML) or download the (PDF, 543 KB). ISBN 978-1-100-25518-7.

Fact sheet text. Click for details.

The AIR QUALITY HEALTH INDEX: How Air Pollution Affects Your Health Fact Sheet

Are you at risk?

Every individual reacts differently to air pollution. Children, the elderly and those with heart or lung disease are most sensitive to the health effects of air pollution. People with diabetes are also at greater risk because they are more prone to heart disease. Even Canadians who are relatively fit and healthy can experience symptoms when exercising or working outdoors if pollution levels are higher than usual.

Air pollution has a measurable impact on human health. An analysis of data from Canadian cities shows that 5,900 deaths can be linked to air pollution every year. Air pollution sends thousands more Canadians to hospital each year. The World Health Organization (WHO) estimates that 1.3 million deaths worldwide can be attributed to urban outdoor air pollution.

The Health Effects of Air Pollution

Depending on the length of time you are exposed, your health status, your genetic background, and the concentration of pollutants, air pollution can:

  • Make it harder to breathe
  • Irritate your eyes, nose and throat
  • Worsen chronic diseases such as heart disease, chronic bronchitis, emphysema and asthma
  • Lead to premature death

Negative health effects increase as air pollution worsens. Studies show that even modest increases in air pollution can cause small but measurable increases in emergency room visits, hospital admissions and death.

What You Can do to Protect Your Health

We can protect our health from the negative health effects of air pollution by appropriately changing our behaviour to reduce our exposure to air pollutants when air quality deteriorates. Checking the Air Quality Health Index on a regular basis is the first step.

The index assesses the impact of air pollution on your health, listing a color coded number from 1 to 10+ to indicate the level of immediate health risk associated with local air quality.

The higher the number, the greater the risk - and the greater your need to take precautions.

The index describes the level of health risk associated with these numbers ow', 'moderate', 'high' or 'very high', accompanied by health advice for the general population and for those at increased risk.

In addition to current air quality health information, a forecast is provided for the next day.

Using the Index to Protect Your Health

The index is available in many communities across Canada. Look for it with weather forecasts (weather.gc.ca) for your community or go to airhealth.ca. The index is also available at theweathernetwork.ca. Use the forecasts to plan your activities, whether over the next hour or the next day.

Seniors, children and people with asthma, diabetes, heart or lung disease, can use the index to assess the immediate risk air pollution poses to your health and take steps to lessen that risk.

Even if you're relatively healthy, fit and active, you should consult the index to decide when and how much to exercise or work outdoors.

The index can't perfectly measure the health effects of the air you breathe. Pollen, dust, heat/humidity and odourscan affect your health. Always pay attention to what your body is telling and follow your doctor's advice.

The Air Quality Health Index
Health Risk Air Quality Health Index Health Messages
At Risk Population*
Health Messages
General Population
Low 1 - 3 Enjoy your usual outdoor activities. Ideal air quality for outdoor activities.
Moderate 4 - 6 Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms. No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.
High 7 - 10 Reduce or reschedule strenuous activities outdoors. Children and the elderly should also take it easy. Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.
Very High Above
10
Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion. Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.

* Unsure if you are at risk? Consult this health guide to help you determine if you are at risk from air pollution. People with heart or breathing problems are at greater risk. Follow your doctor's usual advice about exercising and managing your condition.

For more information, visit airhealth.ca.

 

Air Quality Health Index FAQ thumbnail

Frequently Asked Questions

The Frequently Asked Questions (FAQs) is an 11 page factsheet that provides additional information on air quality and health and the Air Quality Health Index.

To order, contact publications@hc-sc.gc.ca.  Available in English or French. View or download the FAQs here HTML or PDF (1014 KB). ISBN 978-1-100-25516-3.

Air Quality Health Index Poster thumbnail

Poster

The poster includes the Air Quality Health Index scale, and the slogan "be air aware". A web address is included for further information. Bilingual: English one side and French on the other.

To order, contact publications@hc-sc.gc.ca. Bilingual.  See below for poster text (HTML) or download the PDF (3721 KB).

Poster text. Click for details.

Air Quality Health Index - Be air aware

The Air Quality Health Index relates air quality to your health on a simple scale from 1 to 10+. The higher the number the higher the risk. Know when to be active. Protect your health! airhealth.ca

 

Air Quality Health Index Health Professional Kit thumbnail

Resource Kit

The resource kit includes a small poster, tear sheets, flip top brochure and slide rule, all contained in a colorful folder. The kit is a useful tool for teachers, health practitioners and others that want to learn and inform their students, clients, etc about the usefulness of the AQHI.

To order, contact publications@hc-sc.gc.ca. Bilingual. Printed version only.

Air Quality Health Index Slide Rule thumbnail

Slide Rule

The AQHI slide rule is an interactive tool that can be set to the Air Quality Health Index (AQHI) daily value.  The slide rule includes health protection messages for the general public and the at-risk population.

To order, contact publications@hc-sc.gc.ca. Bilingual.  See below for slide rule text (HTML) or download the sleeve PDF (623 KB) and insert PDF (1008 KB).

Slide rule text. Click for details.

Sleeve:

The Air Quality Health Index - Be air aware

The Air Quality Health Index relates air quality to your health on a simple scale from 1 to 10+. The higher the number, the higher the risk.

What is today's AQHI?

Insert:

Air Quality Health Index

Health Risk Air Quality Health Index Health Messages
At Risk Population*
Health Messages
General Population
Low 1 - 3 Enjoy your usual outdoor activities. Ideal air quality for outdoor activities.
Moderate 4 - 6 Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms. No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.
High 7 - 10 Reduce or reschedule strenuous activities outdoors. Children and the elderly should also take it easy. Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.
Very High Above
10
Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion. Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.

* People with heart or breathing problems are at greater risk. Follow your doctor's usual advice about exercising and managing your condition.

 

Air Quality Health Index Tearsheet thumbnail

Tearsheets

The tearsheet is a quick reference guide to the Air Quality Health Index, and is ideal for health professionals or anyone looking to distribute concise information on the AQHI. Each tearsheet includes a chart with information on the health risk for different Air Quality Health Index values, including advice for both the at-risk population and the general public.  The tearsheets come in a pad of 150 sheets.

To order, contact publications@hc-sc.gc.ca. Available in English or French.  See below for tearsheet text (HTML) or download the PDF (1301 KB).

Tearsheet text. Click for details.

Air Quality Health Index - Be air aware

The Air Quality Health Index is designed to help you understand what air quality means for your health and make decisions to protect yourself by limiting exposure to air pollution.

The Air Quality Health Index
Health Risk Air Quality Health Index Health Messages
At Risk Population*
Health Messages
General Population
Low 1 - 3 Enjoy your usual outdoor activities. Ideal air quality for outdoor activities.
Moderate 4 - 6 Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms. No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.
High 7 - 10 Reduce or reschedule strenuous activities outdoors. Children and the elderly should also take it easy. Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.
Very High Above
10
Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion. Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.

* People with heart or breathing problems are at greater risk. Follow your doctor's usual advice about exercising and managing your condition.

 

Weather and Air Quality Wall Poster thumbnail

Weather and Air Quality Wall Poster

This poster explains how different meteorological conditions impact air quality. In many parts of Canada, we often have days with clean air, followed by heavy smog, and then a sudden return to clear, fresh air. The amount of pollutants released daily into the air does not usually change so quickly, so what is happening? Surprisingly, the weather is the switch that turns smog on and off.  83.5 cm x 61.5 cm. 

Bilingual.  See below for poster text (HTML) or download the PDF (3018 KB).

Poster text. Click for details.

Weather and air quality

Air Quality

Over the past few decades, the air in Canada has been getting steadily cleaner, as considerable efforts have been made to reduce air pollution. However, many sources of pollution remain, such as cars, trucks, factories, wood stoves and road salt.

In many parts of Canada, we often have days with clean air, followed by heavy smog, and then a sudden return to clear, fresh air.  The amount of pollutants released into the air does not usually change so quickly, so what is happening? Surprisingly, the weather is the switch that turns smog on and off. 

Air pollutants can have a serious impact on our health. This is why Environment Canada produces the Air Quality Health Index (AQHI) daily. This public information tool provides air quality information and forecasts.  The Index lets you plan ahead to protect your health and the health of those close to you.

How the Weather Affects Air Quality

The Wind 

The wind can carry pollutants towards us or away from us.  Smoke from forest fires, as well as other less visible pollutants, can be carried over long distances to arrive on our doorstep.  When there is little or no wind, local pollutants build up in the air.  We see this in both summer and winter under temperature inversions that come with light or no wind.

Temperature Inversion.

Hot air rises - this is how hot air balloons work.  We normally have warm air at ground level, and cooler air above.  In a temperature inversion, the temperatures are upside down - the cooler air is at ground level, and the warmer air higher up.  The cooler air cannot rise, and the warmer air above acts like a lid, trapping pollutants at the ground where we live and breath.

Warm Sunny Days

Hot sunny days in the summer may be accompanied by smog.   The intense summer sun causes chemical reactions among the pollutants that are already in the air, leading to the formation of ground-level ozone, a major component of smog.

Rain and Snow

We all know how the air feels cleaner and fresher after it rains. This is because both rain and snow clean the air, removing most of the pollutants. However, these do not disappear by magic from the environment; they are absorbed into the ground and into the streams.

… and the Lay of the Land

Hills, mountains, valleys, flat plains, and rolling prairie can affect the movement of air and the pollutants it carries.  In valleys at night, the air settles in, trapping its burden of pollutants.  A brisk wind blowing over a flat open area will help to scatter pollutants, improving local air quality.

Smog

Smog  is a mixture of air pollutants that are harmful to our health and the environment.  It can occur year round, although the combination of pollutants can change from summer to winter.  In summer, the main component of smog is usually ground level ozone, although occasionally winds carrying smoke from forest fires can bring large amounts of small suspended particles. In winter, smog consists mostly of small suspended particles, caused by car exhaust and burning wood in stoves and fireplaces.

*Ozone is a natural gas found in the atmosphere. In the higher atmosphere, it forms a protective layer that intercepts the majority of the dangerous ultraviolet rays, but in the lower atmosphere, or troposphere, where we live, it is a nuisance to human beings and constitutes a pollutant. 

Monitoring and Forecasting air quality

Measuring, processing and forecasting

In partnership with provinces, territories and municipalities across Canada, Environment Canada measures and studies outdoor air quality.  Over 350 monitoring stations, containing a variety of sophisticated measuring instruments, are part of the National Air Pollution Surveillance (NAPS) Program. This program gathers and shares these data with scientists across North America to track and understand changes in air quality. 

Environment Canada uses these data in its world-class air quality forecast model, a highly specialized computer program that simulates how air pollution changes with time.  Developed by Environment Canada scientists, the GEM-MACH 15* model is hosted on a supercomputer in Montreal. The model combines air pollution emissions with changing weather conditions, to produce an air quality forecast. This forecast focuses on the three pollutants that make up the Air Quality Health Index: ground level ozone, nitrogen dioxide and fine particulate matter.

Environment Canada’s forecasting team uses this model output, current conditions, local knowledge, and other factors to produce Air Quality Health Index forecasts.  The meteorologist’s knowledge of the role of weather in predicting smog is making an important contribution to public health.  This gives Canadians advance notice of air quality conditions, enabling them to plan their activities for the next day and reduce their exposure to air pollution.

*GEM-MACH : Global Environmental Multi-scale - Modelling Air quality and Chemistry

Environment Canada's Air Quality Health Index

Are you “at-Risk”?

Check your Local Air Quality Health Index at www.ec.gc.ca/cas-aqhi

 

Air Quality Health Index wheel thumbnail

Wheel

This is an interactive spin tool that can be set to the Air Quality Health Index (AQHI) daily value.  The wheel includes health protection messages for the general public and the at-risk population, along with images of appropriate activity levels corresponding to the AQHI value. 

To order, contact publications@hc-sc.gc.ca. Bilingual.  Printed version only. 

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: