Air Quality Health Index

The Air Quality Health Index (AQHI) provides an hourly rating of air quality based on the health risk from a mixture of 3 air pollutants:

• Particulate matter (PM2.5)
• Ground-level ozone (O3)
• Nitrogen dioxide (NO2)

The rating for the AQHI is based on the combination of the health risks from each of the pollutants in the index. This method differs from the older Air Quality Index (AQI), which determined air quality based on the highest value of only one pollutant.

British Columbians can use the AQHI to check the quality of outdoor air before heading off to work or play.

How to use the AQHI

The AQHI is available to more than 80% of B.C.'s population in 25 communities.

Review the full list in the left-hand navigation.

The AQHI:

• Illustrates the level of health risk with a number and colour scale of 1 to 10+
• Labels the health risk as low, moderate, high or very high
• Provides the predicted air-quality health risk over the next 48 hours
• Provides advice on actions to minimize the health risk from air pollution

Smoke and AQHI adjustments

During smoky periods, the AQHI was sometimes found to under-report health risk. Therefore, an adjustment to the AQHI, called AQHI-Plus, has been made in B.C. to improve the accuracy of the reported health risk from smoke throughout the year.

The adjustment started as a pilot project in May 2018 and was adopted in March 2021, following 2 peer-reviewed health studies supporting its use. Since then, reported AQHI in B.C. follows the AQHI-Plus formula year-round and in all locations.

For more information, contact the B.C. Air Quality team and include 'Information on AQHI and AQHI-Plus' in the subject line.