Part of Air

Air indicators – Fine particulate matter

Air monitoring results for the concentration of fine particulate matter.

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About the indicator

Fine particulate matter, or PM2.5, is an air pollutant that can be harmful to human health. PM2.5 consists of very small particles 2.5 micrometres or less in diameter. Exposure to these small particles can cause serious health problems including lung and heart disease.

This indicator reports on the concentration of PM2.5 from 2000 to 2021 and compares it to Alberta’s Ambient Air Quality Objectives (AAAQOs), which set thresholds for air pollutants to protect human and ecosystem health. This indicator also discusses ongoing management of PM2.5 concentrations in Alberta under the Canadian Ambient Air Quality Standards (CAAQS).

Fine particulate matter facts

  • PM2.5 is emitted into the atmosphere from human activities and natural emission sources such as wildfire smoke. Some PM2.5 is emitted directly into the atmosphere, for example through dust or smoke. PM2.5 also forms through chemical reactions in the atmosphere involving other gases, such as nitrogen dioxidesulphur dioxide and volatile organic compounds.
  • Human caused sources of PM2.5 include using fossil fuels for vehicles, home heating, power plants, and industrial processes. Other sources include home wood burning, brush pile burning, road dust, and construction operations, among others.
  • In Alberta, the highest concentrations of PM2.5 are typically caused by wildfire smoke and winter smog. Smog is a mixture of gases and particles emitted into the air by human activities. Smog negatively affects human health and forms haze that reduces visibility.
  • PM2.5 is part of the Air Quality Health Index (AQHI) that reports on health risks associated with local air quality across Alberta in real-time.

Methodology

Summary of key results

Last updated: April 2023

  • The highest concentrations of PM2.5 in Alberta are caused by wildfire smoke and can reach concentrations that exceed the AAAQO, which is based on the protection of human health. The location and severity of smoke varies year-to-year depending primarily on wildfire intensity and activity.
  • Human activities also significantly contribute to PM2.5 concentrations, primarily during winter smog episodes. Alberta is taking action to manage PM2.5 levels associated with human activities under the CAAQS.

Variation across Alberta

  • Annual average and peak concentrations of PM2.5 vary across Alberta (Figures 1a and 1b, respectively) and are driven primarily by wildfire smoke and winter smog.
    • PM2.5 concentrations are highest in large population centres and near industrial emissions sources. Stations located outside of these areas (for example in regional locations and smaller communities) have lower PM2.5 concentrations.
    • PM2.5 concentrations are also highest in areas more affected by wildfire smoke.
  • Wildfire smoke affects different parts of the province each year. The location of wildfires and the wind patterns that transport smoke determine which regions are affected. For more information on how wildfire smoke affects air quality in Alberta, see: Wildfire Smoke: Impacts on Air Quality in Alberta.
    • In 2021, wildfire smoke from fires burning in British Columbia and the northwestern United States throughout the months of July and August, as well as smoke from wildfires in Saskatchewan in early October, affected much of the province.

Figure 1a. Annual average PM2.5 concentrations across Alberta for 2021

 

Select a circle on the map to view the 2021 concentration for a specific monitoring station.
Source: Government of Alberta

Figure 1b. Peak PM2.5 concentrations across Alberta for 2021

 

Select a circle on the map to view the 2021 concentration for a specific monitoring station.
Source: Government of Alberta

Changes over time

  • The difference in PM2.5 concentrations between years is largely driven by the extent of wildfire smoke and the frequency and severity of winter smog episodes (Figures 2a and 2b).
  • In 2021, provincial average concentrations of PM2.5 were similar to other years over the past decade (for example, 2011 to 2015 annual averages; 2015 and 2016 peak values).
    • Annual average and peak PM2.5 concentrations were higher in 2021 compared to 2020, when there was reduced wildfire activity in Alberta and limited impact from wildfires in surrounding jurisdictions.
    • Actions taken in response to COVID-19 may have also affected PM2.5 due to changes in emissions of air pollutants from sources such as vehicle traffic.
  • Trends over time for PM2.5 cannot be tested statistically because of changes in monitoring equipment (see limitations section below).

Figure 2a. Trends in annual average PM2.5 concentration over time

Chart data table
Year Provincial Average 10th Percentile 90th Percentile Calgary Edmonton Fort McMurray Grande Prairie Lethbridge Medicine Hat Red Deer CAAQS
2000 8.1 6.3 10.8 10.1 11.3 6.5 8.8
2001 7.2 3.3 9.7 9.5 10.2 6.9 8.6 8.8
2002 5 2.9 6.9 6.3 6.9 4.7 5.5 8.8
2003 5.6 3.2 7.7 8.1 7.3 3.6 5.7 8.8
2004 4.9 3.2 6.7 6.4 6.5 4.2 4.1 3.1 5 8.8
2005 4.5 3.3 6.5 5.5 5.4 3.6 4.6 3.3 3.1 4.5 8.8
2006 5 3.8 6.9 6.6 5.7 4.3 5.2 4 3.5 5.4 8.8
2007 4.8 3.4 7 5.7 5.3 4.6 4 3.6 3.5 4.2 8.8
2008 4.9 3.4 6.9 5.7 6 4.9 4.1 3.6 3.4 4.4 8.8
2009 5.5 3.7 8.5 9 7.9 4 4.8 3.8 8.6 8.8
2010 8.2 4.6 14.4 11.4 14.8 4.6 10.8 7.7 16.2 8.8
2011 6.9 3.4 10.3 10.9 9.7 8.2 8.4 6.6 7.8 13.7 8.8
2012 6.9 4.6 9.4 10 8.7 6 6.5 9.4 10.2 8.8
2013 6.4 3.6 8.6 8.1 8.7 6.4 6.3 7 10.4 8.8
2014 7 4.3 9.1 8.2 9.8 8 8.2 7.1 4.8 7.1 8.8
2015 7.1 4.1 9.4 8.1 9 8.5 6.4 8.2 6.6 8.8 8.8
2016 6.6 3.9 9.7 5.2 7.3 19 6.1 4.8 4 5.7 8.8
2017 6.4 4.5 8 7.9 7.9 5.9 6.7 7.5 5.8 6.8 8.8
2018 8.9 6.6 11.6 11.2 10.2 7.6 9.9 9.3 6.9 9.5 8.8
2019 6.3 4.7 8.1 7.1 7.6 6.4 6.9 5.4 4.6 6.9 8.8
2020 5.2 4 6.7 6.3 6.2 5.5 4.9 5.3 5.2 5.2 8.8
2021 7.2 5.5 8.7 8.4 8.9 7 6.1 7 7.2 7.4 8.8

Source: Government of Alberta

The horizontal dashed lines represent the 2020 Canadian Ambient Air Quality Standards. The Canadian Ambient Air Quality Standards are provided for illustrative purposes only and not for assessing the achievement status of the standards. For information on achievement status see the Alberta Air Zones report.
Table description

Line chart showing the change over time in annual average PM2.5 concentrations for large urban centres in Alberta, the provincial average, and the 10th and 90th percentile of all PM2.5 monitoring stations in the province. The highest annual average concentration was measured in Fort McMurray in 2016 with a value of 19 µg/m3. Years that are impacted more by wildfire smoke and wintertime smog episodes have higher annual average concentrations (for example: 2010, 2011, and 2018). The chart also displays the 2020 Canadian Ambient Air Quality Standard for PM2.5 annual average (8.8 µg/m3) for comparison.

Figure 2b. Trends in peak PM2.5 concentrations over time

Chart data table
Year Provincial Average 10th Percentile 90th Percentile Calgary Edmonton Fort McMurray Grande Prairie Lethbridge Medicine Hat Red Deer CAAQS
2000 17.6 13.5 23.7 22 24.9 13.7 27
2001 17.5 9.5 22.4 20.8 24 15.9 20.9 27
2002 17.7 11.5 24.5 18.8 23.4 15.2 15.3 27
2003 19.9 11.5 33.5 35.5 24 11.5 20.9 27
2004 17.6 13.6 21.6 17.6 21.4 1.5 14.2 15.7 13.8 27
2005 12.9 8.9 16.6 13.2 14.4 12.7 14.8 10.1 8.8 10 27
2006 14.9 11.7 18.4 18.3 17.8 14.1 16.4 12.3 9.5 14.5 27
2007 14 10.3 16.8 16.2 14.8 15.1 11.9 12 10.5 11.8 27
2008 14.3 9.8 19.9 14.5 18.6 14.9 11.5 9.8 10 11.6 27
2009 16.1 11.9 22.4 19.5 21.5 13.9 14.7 12.5 24.3 27
2010 28 16.3 41.4 30.8 46.4 16.4 29.1 25.7 37.5 27
2011 26.9 11.3 60.5 24 26.9 72.4 20.3 18.5 18 34.1 27
2012 21.3 13.3 31.5 21.9 22.3 20.8 19.5 23.4 22.3 27
2013 18.1 10.3 24 20.8 29.5 17 17.6 17.1 34.5 27
2014 25.7 16.7 34.1 21.2 26 35.1 35.9 20.9 16.5 20.4 27
2015 31.9 17 48.1 28.1 23.7 40.9 20.9 42 45.5 24.5 27
2016 31.2 11.9 49.4 14.7 22.7 208.4 21 14.6 10.7 16.5 27
2017 25.8 14.9 34.9 34.6 29 15.9 26.3 44.9 29.3 29 27
2018 52 32.8 65.9 58.1 49.1 35.4 60.5 58.4 43 50.5 27
2019 21.7 15.3 28 19.2 26.2 21.5 23.8 20.8 13.7 18 27
2020 15.8 10.8 20.1 18.9 20.6 12.6 17.9 20.5 16.3 15.6 27
2021 32.9 26.2 42.4 44.2 38.4 25.9 29.7 39.5 38.2 32.8 27

Source: Government of Alberta

The horizontal dashed lines represent the 2020 Canadian Ambient Air Quality Standards. The Canadian Ambient Air Quality Standards are provided for illustrative purposes only and not for assessing the achievement status of the standards. For information on achievement status see the Alberta Air Zones report.
Table description

Line chart showing the change over time in peak PM2.5 concentrations for large urban centres in Alberta, the provincial average, and the 10th and 90th percentile of all PM2.5 monitoring stations in the province. The highest peak concentration was measured in Fort McMurray in 2016 with a value of 208.4 µg/m3. Years that are impacted more by wildfire smoke and wintertime smog episodes have higher peak concentrations (for example: 2011 and 2016 at Fort McMurray specifically, and 2018 province-wide). The chart also displays the 2020 Canadian Ambient Air Quality Standard for PM2.5 24-hour (27 µg/m3) for comparison.

​Seasonal variation

  • Higher concentrations of PM2.5 occur during periods affected by wildfire smoke (Figure 3).
  • Elevated concentrations also occur during winter smog episodes caused by human emissions from November to March. Winter smog has a smaller effect on PM2.5 concentrations compared to wildfire smoke, which is why smog contributions are not as apparent in Figure 3 as those from wildfires.
    • Winter smog typically occurs during temperature inversions, when cold air along with pollutants are trapped at ground level preventing dispersion of pollutants into the atmosphere.
  • PM2.5 concentrations can also be elevated at other times of year due to summer smog episodes, high wind dust events and other local causes.

Figure 3. Seasonal variation in monthly average PM2.5 for 2018 to 2021, shown using bar plots of the median monthly value across all long-term air monitoring stations. Whiskers extend from the top of the bar to the maximum monthly value across all stations. Major wildfire episodes are indicated for each year.

Source: Government of Alberta

Bar charts showing the median monthly average PM2.5 concentration for each month as bars, with lines extending up from the top of the bars to the maximum monthly average concentration. The chart has four panels; one for each year from 2018 to 2021. Each panel includes a label indicating when wildfire smoke impacted the province. In 2018, the highest median monthly average concentration is in August during the BC wildfires. In 2019, the highest concentrations are in May and June, when wildfires were burning in northwestern Alberta. In 2020, there is less impact from wildfire smoke due to the wildfires in western United States in August and September. Monthly average concentrations for these months are similar to the winter months. In 2021, the highest concentrations occur in July and August due to smoke from wildfires burning in northwestern United States and in BC.

Comparison to provincial objectives

  • Alberta’s Ambient Air Quality Objectives (AAAQOs) provide maximum acceptable thresholds for over 30 airborne compounds to protect human and ecosystem health. All industrial facilities must be designed and operated to remain below these thresholds. When air quality exceeds an AAAQO, the Alberta government assesses the cause and determines whether corrective action is required.
  • Exceedances of the 24-hour AAAQO for PM2.5 are mainly caused by wildfire smoke and winter smog episodes (Figure 4). In 2021, there were 473 exceedances of the 24-hour AAAQO for PM2.5 in various locations across Alberta. Some air monitoring stations experienced up to 19 days of exceedances. The AAAQO for PM2.5 is 29 µg/m3 for 24-hour periods based on the protection of human health.

Figure 4. Cause of PM2.5 exceedances in 2021 across Alberta

Chart data table
Category Percentage
Wildfire 91.3
Winter smog and burns 7.4
Other 1.3
Source: Government of Alberta
Table description

Pie chart showing causes of PM2.5 exceedances in 2021 across Alberta. Most (91.3%) PM2.5 AAAQO exceedances in Alberta in 2021 were attributed to wildfire smoke. 7.4% occurred during the winter due to wintertime smog or prescribed burning activity. The remaining 1.3% were attributed to other sources.

Comparison to national standards

  • To guide management of air quality across Canada, the Canadian Ambient Air Quality Standards (CAAQS) have been developed for the following air pollutants: fine particulate matter (PM2.5), nitrogen dioxide (NO2), ground level ozone (O3) and sulphur dioxide (SO2).
  • Analyses against the CAAQS specifically assess human-caused air quality issues that can be controlled through management actions while events outside the control of jurisdictions, such as wildfire smoke, are not included.
  • PM2.5 levels approach the CAAQS in several regions of the province, primarily due to winter smog caused by human emissions.
  • Annual reporting of Alberta’s air quality against the CAAQS is available in Alberta's
    Air Zone Reports.
    • For the 2018-2020 reporting period, 4 areas of the province were at the Orange Level – Actions for Preventing CAAQS Exceedances. The remaining two areas of the province (the Peace Region and Red Deer Region) were at the Yellow Level – Actions for Preventing Air Quality Deterioration.
    • Work is ongoing to prevent exceedances of CAAQS through air quality management plans. For details, see the Canadian Ambient Air Quality Standards under ‘Management plans’.

Limitations of the dataset

  • Between 2010 and 2017, older equipment at Alberta’s monitoring stations was replaced with new monitoring equipment for PM2.5. These new instruments measure an additional portion (semi-volatile) of the PM2.5 mass not captured by older instruments.
  • As older monitoring equipment used between 2000 and 2017 likely underreported concentrations of PM2.5 under some conditions, after 2010, the increase in PM2.5 concentrations may be a result of changes in monitoring equipment. Concentrations measured with the new monitors may not be directly comparable with measurements from years in which older instruments were used.

Focused study

In response to an exceedance of the national Canadian Ambient Air Quality Standards (CAAQS) in the Red Deer area in the 2011-2013 assessment, a focused study was initiated to measure PM2.5 composition and precursor gases at 3 monitoring stations between 2017 and 2019. The objective of the study was to assess PM2.5 regional and local sources and inform management actions to improve air quality.

Key findings include:

  • Elevated PM2.5 concentrations were regional scale events, with similar and correlated concentrations observed at two stations in Red Deer, and at a site located 9.4 km upwind.
  • When wildfire-impacted samples are removed, PM2.5 concentrations are largest in the spring, and are dominated by the sulphate and nitrate factors (74%) (Figure 5).
  • The sulphate factor is consistent with a regional source, which could include the coal-fired power plants and the smaller upstream oil and gas operations in the area. The elevated nitrate factors appeared to be affected by local emissions sources, which could include both urban and industrial sources, and promoted by meteorological conditions.
  • Reducing oxides of nitrogen could help to manage PM2.5 concentrations in the region.

Figure 5. Relative contribution to PM2.5 mass at Red Deer study monitoring sites

Chart data table
Category Percentage
Road 2% 2.43
Biogenic <1% 0.72
Selenium 2% 2.37
Carryover 6% 6.23
Nitrate 56% 56.13
Fresh smoke <1% 0.02
Sulphate 18% 18.42
Secondary Organics 11% 11.40
Crustal matter 2% 2.28
Source: Government of Alberta
Table description

Pie chart showing relative contribution to PM2.5 mass at the Red Deer study monitoring sites. The nitrate and sulphate factors have the largest contribution, at 56% and 18%, respectively. Secondary organics are the third largest contributor at 11%. The remaining 15% is made up of six factors (carryover, road, selenium, crustal matter, biogenic, and fresh smoke).