How the new index works

The new index ranks air quality from 1 to 10+. The lower the number the lower the risk. It helps you understand what the quality of the air around you means to your health - just like the UV index informs you of the harmful effects of too much sun.

Previous air quality systems reported air quality relative to air quality objectives established for different pollutants and addressed each pollutant separately. The new Air Quality Health Index provides information on the immediate health risk associated with  the combined effects of air pollution (smog) mixture.

When the Air Quality Health Index reading rises, protect your health by:

  • reducing or rescheduling outdoor physical activities
  • monitoring possible symptoms, such as difficulty breathing, coughing or irritated eyes
  • following your doctor’s advice to manage existing conditions such as asthma
  • doing your part by taking public transit

The health index will be available to the 39 stations currently included in the provincial ambient air monitoring network. Most of the province’s air monitoring stations are located in communities in southern Ontario where there are higher levels of pollution from a greater number of people, cars and industry.