Table 1 Descriptive air pollution statistics by site
Centre (dates) | Pollutant | Number of days | Mean | 25th percentile | 75th percentile | Standard Deviation | Percent missing |
|---|---|---|---|---|---|---|---|
Montreal | CO (ppm) | 2191 | 0.5 | 0.3 | 0.6 | 0.2 | 0.0 |
(1/97–12/02) | NO2 (ppb) | 2191 | 19.4 | 14.0 | 23.5 | 7.6 | 0.0 |
| Â | SO2 (ppb) | 2191 | 4.8 | 2.7 | 6.1 | 3.0 | 0.0 |
| Â | O3 (ppb) | 2191 | 18.3 | 11.4 | 23.5 | 9.5 | 0.0 |
|  | PM10 (μg/m3) | 1092 | 25.8 | 15.9 | 31.9 | 14.2 | 50.2 |
|  | PM2.5 (μg/m3) | 1938 | 8.6 | 4.1 | 10.9 | 6.7 | 11.5 |
Ottawa | CO (ppm) | 3074 | 0.9 | 0.5 | 1.1 | 0.5 | 0.0 |
(4/92–12/00) | NO2 (ppb) | 3066 | 18.8 | 12.7 | 24.0 | 8.8 | 0.3 |
| Â | SO2 (ppb) | 3045 | 3.9 | 1.7 | 5.6 | 3.0 | 1.0 |
| Â | O3 (ppb) | 3049 | 17.5 | 11.5 | 23.0 | 8.3 | 0.8 |
|  | PM10 (μg/m3) | 361 | 20.1 | 12.0 | 24.1 | 11.3 | 88.3 |
|  | PM2.5 (μg/m3) | 954 | 6.7 | 3.0 | 8.7 | 5.2 | 69.0 |
Edmonton | CO (ppm) | 3652 | 0.7 | 0.4 | 0.8 | 0.4 | 0.0 |
(4/92–3/02) | NO2 (ppb) | 3652 | 21.9 | 14.7 | 27.6 | 9.4 | 0.0 |
| Â | SO2 (ppb) | 3616 | 2.6 | 1.3 | 3.5 | 1.8 | 1.0 |
| Â | O3 (ppb) | 3652 | 18.6 | 11.3 | 25.2 | 9.3 | 0.0 |
|  | PM10 (μg/m3) | 2813 | 22.6 | 13.3 | 28.3 | 13.1 | 23.0 |
|  | PM2.5 (μg/m3) | 1440 | 8.5 | 4.6 | 10.9 | 6.2 | 60.6 |
Saint John | CO (ppm) | 1225 | 0.5 | 0.2 | 0.8 | 0.3 | 10.6 |
(7/92–3/96) | NO2 (ppb) | 1363 | 9.3 | 5.1 | 12.3 | 5.5 | 0.5 |
| Â | SO2 (ppb) | 1369 | 7.7 | 2.7 | 10.6 | 7.0 | 0.1 |
| Â | O3 (ppb) | 1367 | 20.1 | 14.6 | 24.4 | 7.5 | 0.2 |
|  | PM10 (μg/m3) | 0 |  |  |  |  | 100.0 |
|  | PM2.5 (μg/m3) | 0 |  |  |  |  | 100.0 |
Halifax | CO (ppm) | 1032 | 0.5 | 0.4 | 0.6 | 0.2 | 34.8 |
(1/99–12/02) | NO2 (ppb) | 991 | 17.5 | 13.6 | 21.0 | 5.8 | 37.4 |
| Â | SO2 (ppb) | 1093 | 10.0 | 5.6 | 13.4 | 6.6 | 31.0 |
| Â | O3 (ppb) | 1096 | 22.1 | 16.4 | 27.1 | 7.9 | 30.8 |
|  | PM10 (μg/m3) | 0 |  |  |  |  | 100.0 |
|  | PM2.5 (μg/m3) | 526 | 9.8 | 4.7 | 11.3 | 9.0 | 66.8 |
Toronto | CO (ppm) | 1552 | 1.0 | 0.7 | 1.3 | 0.4 | 0 |
(4/99–6/03) | NO2 (ppb) | 1552 | 22.7 | 17.6 | 27.5 | 7.6 | 0 |
| Â | SO2 (ppb) | 1552 | 4.2 | 2.4 | 5.4 | 2.6 | 0 |
| Â | O3 (ppb) | 1552 | 22.0 | 14.3 | 28.6 | 10.6 | 0 |
|  | PM10 (μg/m3) | 1006 | 20.7 | 13.7 | 25.7 | 10.3 | 35.2 |
|  | PM2.5 (μg/m3) | 1552 | 9.1 | 4.3 | 11.9 | 7.1 | 0 |
Vancouver | CO (ppm) | 1520 | 0.6 | 0.4 | 0.6 | 0.2 | 0.0 |
(1/99–2/03) | NO2 (ppb) | 1520 | 18.7 | 13.6 | 19.7 | 4.6 | 0.0 |
| Â | SO2 (ppb) | 1520 | 2.6 | 1.4 | 3.3 | 1.5 | 0.0 |
| Â | O3 (ppb) | 1520 | 10.3 | 8.4 | 19.3 | 7.4 | 0.0 |
|  | PM10 (μg/m3) | 1520 | 13.6 | 9.0 | 15.9 | 4.9 | 0.0 |
|  | PM2.5 (μg/m3) | 1082 | 6.8 | 3.5 | 8.5 | 3.6 | 28.8 |