Launch of New Air Quality Health Index in Ontario

August 01, 2025

To help the public better understand the importance of air quality and its health effects, Ontario launched a new Air Quality Health Index (AQHI) on June 24, which was developed and designed by Environment Canada and the Ontario Ministry of Environment and Climate Change along with experts from the Ministry of Health and Long Term Care, Public Health Ontario and Health Canada. The index helps members of the public and those at risk better protect themselves from the health risks associated with poor air quality.

The new Air Quality Health Index which has a simplified scale from 1-10+ with four categories of “low, moderate, high, and very high risk”, will replace the current Air Quality Index (AQI) in the province. The new Air Quality Health Index (AQHI) will forecast and report on air quality with an increased focus on health-based messaging and information for both the general population and at risk groups (children, seniors, and people with diabetes, heart and lung disease).

Ontarians deserve the best possible information about the quality of their air. The index is designed to help them make decisions to protect their health during episodes of increased air pollution. When the Air Quality Health Index reading rises, those at risk can: 

  • Avoid or reduce strenuous physical activities 
  • Avoid or reduce exercising near areas of heavy traffic 
  • Reduce your activity level if you begin to cough and wheeze, feel chest tightness or have trouble breathing 
  • Stay indoors in a cool environment when possible

QUOTES

“The new Air Quality Health Index will help people better understand their level of risk from air pollution based on their age, health status and level of outdoor activity, and what to do to limit their exposure. The index will provide Ontarians with important information about the air they breathe and the best time to enjoy their favourite, outdoor activities.”

— Dr. David Mowat, Interim Chief Medical Officer of Health

Information on the air quality health index in the Waterloo Region can be obtained from Air Quality Ontario. For notifications, subscribe to the Air Quality Alert Notification for the Waterloo-Wellington region which will notify you of Special Air Quality Statements (SAQS) or Smog and Air Health Advisories (SAHA). For additional information on outdoor air quality, see Environment Canada’s Frequently Asked Questions page. Be a good neighbour: share this information with those that may need it.

QUICK FACTS

  • The 2013 Air Quality in Ontario report shows that in 2013, air quality measurements fell into the good or very good category for 94 per cent of the year. For the first time in 20 years, no smog advisories were issued due to ozone levels in Ontario.
  • Ontario already has one of the most modern air monitoring systems in North America. The enhanced Air Quality Health Index will add to Ontario’s robust air quality monitoring and reporting system by communicating information about health risks due to air pollution.
  • Ontario’s action to end coal-fired power is the single largest greenhouse gas reduction initiative in North America, equivalent to taking seven million cars off the road.

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Media contact: Kirsten Keil-Mehlenbacher, Coordinator, Health Communications, 519-575-4400 ext. 2244