Air Quality Remains Low Risk in Fourth Quarter of 2024 Despite Isolated High Risk Air Quality Events

From October through December 2024, Heartland Air Monitoring Partnership (HAMP) Airshed maintained predominantly low risk Air Quality Health Index (AQHI) hourly ratings, with only a few isolated high risk events mostly attributed to wintertime temperature inversions.

In winter, a temperature inversion occurs when cold air is trapped near the ground by a layer of warm air, which acts like a lid holding emissions down. This warm inversion layer temporarily elevated levels of fine particulate matter (PM_2.5) throughout the entire Edmonton Metropolitan Area, including the HAMP region.

HAMP recorded 15,015 hours of air monitoring data for calculating the AQHI: 

• 14,736 (98.14%) of the hours were low risk AQHI 
• 275 (1.83%) of the hours were moderate risk AQHI
• 4 (0.03%) of the hours were high risk AQHI
• No hours were recorded at very high risk AQHI

There were two fine particulate matter (PM_2.5) exceedances of the 1-hr Alberta Ambient Air Quality Objectives (AAAQOs) and two exceedances of the 24-hour objectives, on December 16 and 22. These exceedances were directly related to wintertime inversion conditions, except for one exceedance caused by industry operations. Other than wildfire smoke, common sources of fine particulate matter include industrial emissions, home heating, fireplaces and barbecues.

Three-Year AQHI Rating Comparison in Fourth Quarters: 

Note: New in 2024, Alberta implemented a revised AQHI to provide earlier health risk warnings to Albertans during exceptional or rapidly changing wildfire events. Due to this change, an increased number of high and very high AQHI ratings is likely during air quality events compared to previous years, some of which the source may be undetermined.

For more details: October to December 2024 air monitoring report.