The AQHI provides a number on a 1 to 10 scale to indicate the level of relative health risk associated with local air quality. This scale is intended as a self-calibrating tool; people may use their own experience and symptoms as a guide. The general population and at-risk population (children, elderly people, and those with pre-existing respiratory or cardiovascular disease) may adjust their daily behaviour as needed depending on the current observation and forecasted AQHI value.
The higher the AQHI number, the greater the potential health risk and need to take precautions.
Occasionally during extreme pollution events, such as a wildfire smoke event, AQHI levels may reach 7 – 10, indicating High Health Risk, or 10+, indicating Very High Health Risk.
Planning Outdoor Activities with the AQHI
The AQHI is designed to help you make decisions to protect your health and the environment by:
- Limiting short-term exposure to air pollution
- Adjusting your outdoor activity during episodes of increased air pollution and encouraging physical activity outdoors on days when the AQHI is lower
- Reducing your personal contribution to air pollution
Each individual reacts differently to air pollution. The AQHI provides specific advice for people who are at risk to the effects of air pollution as well as for the general public.
The AQHI forecasts health risk from air quality, both on an hourly basis and as a maximum for longer periods of the day such as tonight and tomorrow. Check the AQHI in your community before heading off to work or play, and use the forecasts to plan your activities, whether over the next hour or the next day. For more information on AQHI forecasting see:
AQHI Health Messages
Each level of health risk is associated with a pair of health messages, for the at risk and the general populations. It suggests steps you can take to reduce your pollution exposure.
|At Risk Population
|1 – 3
|Enjoy your usual outdoor activities.
|Ideal air quality for outdoor activities.
|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.
|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 Risk
|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.
For more information on those who are at risk, see:
Reducing Air Pollution
We all affect air quality. There are actions everyone can take to reduce air pollution, and keep the air cleaner and healthier for people to breathe.
When the AQHI is in the High or Very High-risk category, each of us can change our actions to pollute less. We can:
- Burn less (fireplace, fire pit)
- Idle less
- Reduce energy usage
- Take transit, bike or walk
For more information see: