Wildfire Smoke, Summertime Smog Lead to High and Very High AQHI Ratings in Third Quarter of 2024

Posted on October 29, 2024

From July through September 2024, Heartland Air Monitoring Partnership (HAMP) Airshed experienced more frequent high and very high Air Quality Health Index (AQHI) hourly ratings than previous quarters – due almost entirely to wildfire smoke (PM2.5) or summertime smog (O3) indirectly caused by wildfire smoke.

HAMP recorded 14,869 hours of air monitoring data for calculating the AQHI: 

  • 12,085 (81.3%) of the hours were low-risk AQHI. 
  • 1,798 (12.1%) of the hours were moderate-risk AQHI.
  • 986 (6.6%) of the hours were high or very high-risk AQHI.

There were 46 fine particulate matter (PM2.5) exceedances of the 1-hr Alberta Ambient Air Quality Objectives (AAAQOs) and 107 exceedances of the 24-hour objectives in the third quarter. 617 of the 1-hour exceedances were due to wildfire smoke and only one was from a local source, far surpassing the number of 1-hour PM2.5  exceedances recorded in the first and second quarters. 

 

One-Hour Exceedances Summary for the First Three Quarters of 2024

Parameter

Q1

Q2

Q3

PM2.5

5

9

618

 

In response to these conditions, air quality advisories were issued May 11 – 13, July 10 – 25, Aug 6 – 16 and Sept 7 – 8.

 

Three-Year AQHI Rating Comparison in Third Quarters

 

Low Risk 

Moderate Risk 

High Risk 

Very High Risk 

Q3 2022

13,401

707

99

3

Q3 2023

11,331

2,317

957

286

Q3 2024

12,085

1,798

546

440

 

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: July to September 2024 air monitoring report.