Santé et Services sociaux Québec

Air Quality Health Index FAQ

More on air pollution This link will open in a new window..
More on information tools on air quality This link will open in a new window..

How was the Air Quality Health Index developed?

The Air Quality Health Index was developed by Health Canada and Environment Canada in collaboration with provincial governments and nongovernmental organizations in the health and environment sectors.

The Air Quality Health Index is the product of a number of years of research and is based on the latest scientific data in the field. The scientists who created it estimated the daily variation in the mortality risk in ten cities from 1998 to 2000 and rated the data on a ten-point scale.

Page top

How is the Air Quality Health Index calculated?

The Air Quality Health Index is calculated according to the relative health risks posed by the combined effects of several harmful air pollutants:

  • Ozone (O3, measured at ground level)
  • Fine particles (PM2.5);
  • Nitrogen dioxide (NO2).

However, it is important to remember that the index does not account for health effects caused by odors, pollen, dust, heat, or humidity.

Page top

How is the Air Quality Health Index implemented?

The Air Quality Health Index is gradually being implemented across Canada. In Québec, the Air Quality Health Index is currently available as a pilot project in Gatineau-Ottawa and Québec City.

Page top

Why is there no Air Quality Health Index for my region?

In Québec, the Air Quality Health Index is being deployed as a pilot project. The Québec City and Gatineau-Ottawa urban areas have been chosen for logistical reasons. If the pilot project results are successful, this tool may be deployed in other urban areas of Québec.

Air Quality Health Index phone alerts are also being implemented gradually. They are currently available in the Québec City area.

Sign up for automatic phone alerts.

Page top

How do I read the Air Quality Health Index?

Health risk scale : 1 (low) to 10 (high).

The Air Quality Health Index is a tool that informs the public about air quality and the associated health risks. Its purpose is to help people already suffering from respiratory or cardiac problems protect themselves from the short term effects of air pollution.

The higher the Air Quality Health Index rating, the more individuals at risk are likely to react to the harmful effects of air pollution (onset or exacerbation of respiratory and cardiovascular symptoms). It is important to take precautions, including

  • Limiting or reorganizing outdoor activities
  • Being alert to the onset and worsening of any symptoms
  • Following your doctor’s advice for managing preexisting conditions such as cardiac or respiratory illnesses

However, each person’s sensitivity to air pollution is different. Symptoms may therefore vary from one person to the next for the same rating. Each person must find their own comfort level by matching their symptoms to a given rating.

What’s more, symptoms may also be caused by exposure to high concentrations of contaminants in your living environment or sensitivity to other factors such as pollen, dust, heat, humidity, viral infections, etc.

To find out more about the effects of air pollution and how to protect yourself, visit the My Health and Air Pollution section.

Page top

What is the difference between the Air Quality Health Index and the Air Quality Index?

These indexes should not be compared, as each has its own distinct benefits and purpose.

The Air Quality Health Index reflects what is currently known about how air pollution affects health. This new tool was designed to help people learn more about the short term health risks.

The Air Quality Index (AQI) This link will open in a new window. has been used for many years throughout Québec. It measures air quality according to the degree different pollutants exceed standards or relative limits. It is used to measure air quality but does not include a scale for health risk.

Page top

What is a smog warning?

The Info-Smog program This link open a new window. provides a daily regional air quality forecast based on the three same categories as the Air Quality Index (AQI): good, acceptable, and poor. When the forecast calls for poor air quality, a smog warning is issued for the regions concerned.

Smog especially affects people with respiratory ailments or heart disease. It is therefore recommended that these individuals avoid intense physical activity outdoors until the smog warning is lifted.

What is the Air Quality Health Index Advisory Service?

This unique free service was specially designed to alert vulnerable individuals when the Air Quality Health Index reaches levels dangerous to their health.

Practical, anonymous, and free of charge, the Air Quality Health Index Advisory Service notifies you and provides recommendations when the health risk from poor air quality is high. The service provides timely notification with the right message when poor air quality becomes a health risk.

Subscribers receive alerts by their choice of email, text, or telephone. Signup is free and anonymous.

Page top

What do I do when I receive an advisory?

Here are a few general tips to help you reduce your health risk when you receive an advisory:

  • Pay close attention to any symptoms you might experience.
  • Stay active but consider reducing the intensity of physical activity while the advisory is in effect.
  • Remember to take any backup medication, such as your bronchodilator or nitro spray with you if you go out, just in case.
  • Always avoid physical activity near high-pollution areas—busy roads, for example.

Each individual may react differently to atmospheric pollution, and other factors may contribute to the appearance of symptoms (see the Health and air pollution page for more information). Consult your health professional for personalized advice.


Previous page  Page top  Printable version