Health effects of air pollution

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Exposure to air pollution

Everyone is exposed to air pollution. Air pollution, even at low levels, has an impact on human health. Science has clearly shown that air pollution leads to disease, increased hospitalizations, and even premature death.

While air pollution is a complex mixture of substances, most health effects are associated with the major components of smog:

Even though air pollution levels are low in Canada compared with those in other countries, addressing air pollution remains a priority for the Government of Canada.

Find out how air pollution can affect your health and who is at risk for getting sick.

Health impacts of air pollution in Canada

The Government of Canada estimates that 15,300 premature deaths per year in Canada can be linked to air pollution from fine particulate matter, nitrogen dioxide and ozone, as outlined in Health Impacts of Air Pollution in Canada – Estimates of Premature Deaths and Nonfatal outcomes - 2021 Report. In terms of annual morbidity outcomes, the number of asthma symptom days is estimated to be 2.7 million, while the count of acute respiratory symptom days amounts to 35 million. The total economic valuation of the health impacts attributable to air pollution in Canada is $120B per year (based on 2016 currency).

Health Canada's analysis makes use of the best available health and air quality data for Canada.

Ambient levels for the pollutants are determined from a combination of:

  • satellite measurements;
  • ground measurements; and
  • air quality computer models.

Maps are created to show:

  • air pollution levels across Canada for each pollutant; and
  • the distribution of the population across Canada.

The exposure of Canadians to air pollution is then estimated by combining the air pollution and population maps.

Health Canada uses a computer called the Air Quality Benefits Assessment Tool (AQBAT). The AQBAT includes mathematical equations that show associations between air pollution and health effects. These equations are based on robust scientific findings. The AQBAT produces an estimate of the number of premature deaths (and other health outcomes) in Canada.

The scientific method used is similar to those used by other health organizations, both in Canada and internationally. All conclude that air pollution has significant impacts on human health.

The technical report Health Impacts of Air Pollution in Canada – Estimates of Morbidity Outcomes and Premature Mortalities - 2021 Report is available for download. For additional information on how the Government of Canada estimates air pollution health impacts, please contact

What are the health risks of air pollution?

Air pollution can affect:

It can also increase the risk of stroke.

Some pollutants and bacteria found mainly indoors are related to specific risks, such as:

Your reaction to air pollution depends on:

  • the type and amount of contaminants you are exposed to
  • your overall health
  • your age

What are the symptoms you may experience because of air pollution?

If you are suffering from the health effects of air pollution, symptoms can include:

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

You may notice these symptoms after a few minutes or hours and then feel better after leaving the affected area. This may be more noticeable if you have not spent much time in affected areas. For example, you may notice a difference after a vacation.

People with lung or heart disease may experience more frequent and severe symptoms. They may also need more medication to reduce these symptoms.

People with lung problems

People with asthma or chronic obstructive pulmonary disease (COPD) may notice that they:

  • have more mucous
  • cough and wheeze more
  • experience shortness of breath

People with heart problems

People with heart failure, heart rhythm problems or angina may experience:

  • light-headedness
  • a chest or arm pain
  • irregular heart beats
  • swelling in the ankles and feet
  • an increase in shortness of breath

Who is most at risk for air pollution health effects?

People who are most at risk for health effects are:

  • older adults
  • young children
  • those who are active outdoors
  • those who have existing heart conditions
  • those who live near industries or busy roadways
  • those who have existing breathing or lung problems and illnesses

Lung conditions

Lung conditions that put people at risk for air pollution health effects include:

  • asthma
  • lung cancer
  • chronic obstructive pulmonary disease (COPD)
    • this is sometimes called chronic bronchitis or emphysema

Heart conditions

People who have previously suffered a heart attack are at risk. Other heart conditions that put people at risk include:

  • heart failure (your heart is too weak to move blood around the body)
  • angina (chest pain that happens when your heart does not get enough oxygen-rich blood)
  • heart rhythm problems like arrhythmia (your heart either beats too fast, too slow or is irregular)

Those with diabetes are also at risk for air pollution health effects. This is because people with diabetes are also likely to have a heart condition.

Young children

Young children breathe in more air in relation to their body weight than people in other age groups. This means that they breathe in more contaminants, so air pollution affects them more.

The body’s defence and lung systems are also not fully developed yet. Therefore, young children cannot easily fight off sicknesses that may result from air pollution.

Older adults

Older adults may have weaker lungs, heart and defence systems. They may also have an undiagnosed lung or heart condition.

Those who are active outdoors

People who play sports or do hard work outdoors breathe faster and more deeply than others. This allows more air pollution to enter the lungs.

Those who live near industries or busy roadways

People who live near industries or busy roadways are closer to major sources of air pollution. They may be exposed to more pollutants from these sources.

What should you do if you think you are suffering from health problems related to air quality?

If you think that you are suffering from health problems related to air pollution, it is important to:

  • keep track of when you get symptoms and when they go away
  • discuss your symptoms with your health care provider

This will help your health care provider determine if your symptoms are related to

  • air quality problems, including indoor air quality issues
  • another health issue

If you are suffering from poor indoor air quality at work, you should:

  • discuss your concerns with your supervisor or health and safety representative
  • contact your provincial or territorial government for information and advice on workplace health and safety


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