Table 4.
Descriptive air pollution statistics in nine cities (April 2004–December 2011).
| CITY | POLLUTANTS | MINIMUM | MEAN | MAXIMUM | IQR |
|---|---|---|---|---|---|
| Algoma | NO2 | 0.0 | 5.1 | 24.0 | 4.0 |
| O3 | 2.0 | 28.5 | 80.0 | 14.0 | |
| PM2.5 | 0.0 | 5.3 | 29.0 | 4.3 | |
| SO2 | 0.0 | 1.1 | 17.0 | 2.0 | |
| Halton | NO2 | 1.0 | 12.9 | 51.2 | 7.7 |
| O3 | 2.0 | 25.8 | 67.7 | 14.0 | |
| PM2.5 | 0.5 | 7.7 | 34.2 | 5.8 | |
| SO2 | 0.0 | 2.3 | 14.0 | 2.0 | |
| Hamilton | NO2 | 1.7 | 13.9 | 63.0 | 9.5 |
| O3 | 1.5 | 26.3 | 70.0 | 13.5 | |
| PM2.5 | 0.0 | 9.8 | 64.2 | 7.6 | |
| SO2 | 0.0 | 4.1 | 35.5 | 4.1 | |
| London | NO2 | 0.0 | 10.9 | 51.0 | 7.0 |
| O3 | 1.0 | 26.3 | 66.0 | 14.0 | |
| PM2.5 | 0.0 | 9.5 | 66.3 | 7.2 | |
| SO2 | 0.0 | 1.7 | 15.0 | 1.0 | |
| Ottawa | NO2 | 1.0 | 8.7 | 47.0 | 7.0 |
| O3 | 1.0 | 24.1 | 66.5 | 13.0 | |
| PM2.5 | 0.0 | 7.0 | 67.7 | 6.3 | |
| SO2 | 0.0 | 0.8 | 13.0 | 1.0 | |
| Peel | NO2 | 2.0 | 13.2 | 54.0 | 9.5 |
| O3 | 1.0 | 25.0 | 69.5 | 13.5 | |
| PM2.5 | 0.0 | 8.5 | 64.9 | 6.8 | |
| SO2 | 0.0 | 1.4 | 12.0 | 1.5 | |
| Toronto | NO2 | 4.5 | 18.5 | 62.1 | 9.4 |
| O3 | 1.5 | 22.5 | 60.7 | 13.4 | |
| PM2.5 | 0.0 | 9.3 | 66.8 | 7.4 | |
| SO2 | 0.0 | 1.8 | 13.7 | 1.8 | |
| York | NO2 | 0.0 | 8.2 | 47.0 | 7.0 |
| O3 | 3.0 | 29.2 | 71.0 | 14.0 | |
| PM2.5 | 0.0 | 6.7 | 27.0 | 6.0 | |
| SO2 | 0.0 | 1.2 | 8.0 | 2.0 | |
| Windsor | NO2 | 2.4 | 15.6 | 55.5 | 8.1 |
| O3 | 1.0 | 25.7 | 68.5 | 16.1 | |
| PM2.5 | 0.8 | 9.5 | 33.6 | 7.4 | |
| SO2 | 0.0 | 4.3 | 24.3 | 4.5 |
Abbreviations: IQR, interquartile range; NO2, nitrogen dioxide; O3, ozone; PM2.5, particulate matter with a median aerodynamic diameter no greater than 2.5 µm. NO2, O3, and SO2 in ppb, PM2.5 in micrograms per cubic meter.