Qualité de l’air extérieur

Air Quality Health Index

The Air Quality Health Index shows how outdoor air quality may affect your health. Values range from 1 to 10+. Higher numbers mean a higher health risk.

Statements and warnings

The Ministry of the Environment, Conservation and Parks and Environment and Climate Change Canada issue:

• Special Air Quality Statements when the Air Quality Health Index is forecast to reach 7 or higher
• Air Quality Warnings when the Air Quality Health Index is forecast to reach 10 or higher due to wildfire smoke

Public Health shares this information to keep the public informed.

The Air Quality Health Index (AQHI) is based on levels of nitrogen dioxide (NO₂), ozone (O₃), and fine particulate matter (PM2.5). The index provides advice for both healthy people and those with heart or lung conditions.

Protect your health

To reduce exposure during poor air quality:

• Stay indoors with windows and doors closed.
• Use a portable air cleaner, if available.
• Use the highest quality furnace filter your system allows and run the fan on recirculate.
• Limit outdoor and strenuous activities.
• Check the AQHI and follow health advice.
• Spend time in spaces with cleaner, filtered air, such as libraries, malls, or community centres.
• If you must be outdoors, wear a well‑fitted N95 or equivalent respirator.

Common outdoor air pollutants

Poor air quality can be caused by pollutants.

• Learn more about carbon monoxide (Air Quality Ontario).
• Learn more about fine particulate matter (Air Quality Ontario).
• Learn more about nitrogen dioxide (Air Quality Ontario).
• Learn more about ozone (Air Quality Ontario).
• Learn more about volatile organic compounds (Environment and Climate Change Canada).
• Sulfur dioxide (SO₂): The Sudbury area has a history of sulfur dioxide issues from smelting activities. SO₂ can cause coughing, breathing trouble, eye irritation, and worsen heart or lung conditions. Levels have improved since the 1970s but can still be a concern so Sudbury has one of the largest SO₂ monitoring networks in Canada. 
  • Real time monitoring levels and risk assessment is available at Sudbury’s Air Quality Monitoring Network Portal.
  • For more information on SO₂, visit airqualityontario.com. 

Sources of outdoor air pollution

Outdoor air pollution can come from:

• vehicle exhaust
• industrial activities
• burning fuels for heating and energy
• wildfire smoke
• wind‑blown dust
• natural sources like pollen

Health effects of poor air quality

Poor air quality can cause:

• coughing, eye irritation, and breathing difficulty
• wheezing, chest pain, dizziness, or shortness of breath

People at higher risk include:

• people with heart or lung disease
• people with asthma
• children
• older adults
• people doing heavy outdoor work or exercise