Fine Particulate Matter (PM_2.5) Comparison*

PM_2.5 is particulate matter less than 2.5 micrometres in diameter, which is small enough to penetrate into the lungs. A human hair is about 70 micrometres in diameter. Sources of particulates include soil dust, road dust, agricultural dust (e.g., harvest), smoke from forest fires and recreational wood burning, vehicle exhaust emissions, and industrial emissions.

Average annual PM_2.5 concentrations for Edmonton and Calgary over the five years from 1998 to 2003 were 8.4 mg/m³ (micrograms per cubic metre) and 7.0 mg/m³. The 2003 concentration for Edmonton was 7.7 mg/m³ and for Calgary 7.8 mg/m³. These concentrations were similar to those of other Canadian cities. Hamilton had the highest concentration in Canada with 12.0 mg/m³. It remained the highest in 2003, but did see a decrease to 10.6 mg/m³. Average concentrations of inhalable particulate matter were all much higher in the American cities. Only Dallas had concentrations similar to those of the Canadian cities. L.A. County had concentrations of 25.0 mg/m³, which was more than double that of Hamilton. All the cities showed decreases in 2003 compared to the five-year average, except for Calgary, Ottawa and New York.

There is a Canada-wide Standard for PM_2.5 levels. The standard is 30 mg/m³ averaged over 24-hours. For the five-year period (1998 to 2003) Edmonton and Calgary both experienced 2 or fewer days in exceedance of the Canada-wide Standard for PM_2.5. This was similar to the number of exceedances of most Canadian cities. Toronto, Quebec City, and Hamilton all had more days that exceeded the limit. Hamilton had the most with 11 days, which was nearly twice as many as any other Canadian city. The 2003 data however showed increases in both Edmonton and Calgary. Edmonton exceeded the Canada-wide Standard for PM_2.5 4 days in 2003, while Calgary exceeded it 11 days. Forest fire smoke drifting into the city from fires in British Columbia and Alberta resulted in Calgary being one of the cities experiencing the fewest days exceeding the national standard for PM_2.5, to being the city that experienced the most. Montreal and Toronto also saw increases. Kamloops saw the sharpest increase from averaging less than 1 day a year to experiencing 10 days in 2003.

Annual Average Fine Particulate (PM2.5) Concentrations in North American Cities (mg/m3)
City/County	5 Year Average (1998-2003)	2003
St. John's	5.1	4.9
Montreal	8.3	8.2
Quebec	8.6	8.0
Ottawa	6.9	7.2
Toronto	8.9	8.1
Hamilton	12.0	10.6
Winnipeg	5.9	5.6
Edmonton	8.4	7.7
Calgary	7.0	7.8
Fort McMurray	5.4	3.4
L.A. County	25.0	22.1
New York	14.9	15.2
Dallas	13.2	12.9
Seattle	10.4	7.9

*The cities were compared by looking at the differences in their annual averages over a five-year period (1998-2003) and their most recent annual averages (2003). The city averages were calculated by finding the average of the annual average values for each station within a city. Each city did not necessarily have the same number of stations and it is important to note that this may affect exactly how representative an average is for a given city. Also, some stations may not have been operational for a majority of the time of the comparison, and therefore only stations that had data for at least four out of the five years were used. These same stations were also used in calculating the 2003 averages. The table below shows the number of stations that satisfied the criteria and were thus used for calculating the city averages.

Average PM2.5 Exceedances of the Canada-wide Standard in Canadian Cities (> 30mg/m3>)
City\County	5 Year Average (1998-2003)	2003
St. John's	0	0
Montreal	4	10
Quebec	6	5
Ottawa	2	4
Toronto	6	7
Hamilton	11	9
Winnipeg	0	0
Edmonton	2	4
Calgary	1	11
Fort McMurray	2	0
Greater Vancouver	0	0
Victoria	0	0
Kamloops	0	10

City\County	# of Stations Used in Analysis
St. John's	1
Montreal	2
Quebec	1
Ottawa	1
Toronto	2
Hamilton	2
Winnipeg	1
Edmonton	1
Calgary	1
Fort McMurray	2
Greater Vancouver	1
Victoria	1
Kamloops	1
L.A. County	9
New York	11
Dallas	9
Seattle	3