Carbon Monoxide Comparison*
Carbon monoxide is a colourless, odourless gas formed when carbon burns with an insufficient supply
of oxygen. The major emission source of CO in urban locations is motor vehicles. Minor sources include fireplaces,
industry, aircraft and natural gas combustion.
The average annual carbon monoxide concentration for the five-year
period of 1998 to 2003 for Edmonton and Calgary was 0.6 ppm. Ottawa and Toronto had the highest concentrations of the
cities compared. Ottawa averaged 0.9 ppm, while Toronto averaged 1.0 ppm. Edmonton and Calgary were close to the values
of Regina (0.6 ppm) and Vancouver (0.7 ppm). The 2003 data showed a decrease to 0.5 ppm for Edmonton and Calgary. All
of the Canadian cities used in the comparison showed a decrease in CO concentrations in 2003 compared
to their five-year average.
|
Annual Average CO Concentrations in Canadian Cities (ppm)
|
|
City
|
5 Year Average (1998-2003)
|
2003
|
|
St. John's
|
0.4
|
0.3
|
|
Montreal
|
0.4
|
0.4
|
|
Ottawa
|
0.8
|
0.5
|
|
Toronto
|
1.0
|
0.6
|
|
Winnipeg
|
0.5
|
0.4
|
|
Regina
|
0.6
|
0.5
|
|
Saskatoon
|
0.4
|
0.2
|
|
Edmonton
|
0.6
|
0.5
|
|
Calgary
|
0.6
|
0.5
|
|
Fort Saskatchewan
|
0.4
|
0.3
|
|
Fort McMurray
|
0.3
|
0.2
|
|
Greater Vancouver
|
0.7<
|
0.6
|
*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.
|
City
|
# of Stations Used in Analysis
|
|
St. John's
|
1
|
|
Montreal
|
6
|
|
Ottawa
|
2
|
|
Toronto
|
1
|
|
Winnipeg
|
3
|
|
Regina
|
1
|
|
Saskatoon
|
1
|
|
Edmonton
|
3
|
|
Calgary
|
3
|
|
Fort Saskatchewan
|
1
|
|
Fort McMurray
|
1
|
|
Greater Vancouver
|
4
|
|
