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. 2009 Jun 10;8:25. doi: 10.1186/1476-069X-8-25

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

SO2 (ppb) 2191 4.8 2.7 6.1 3.0 0.0

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

SO2 (ppb) 3045 3.9 1.7 5.6 3.0 1.0

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

SO2 (ppb) 3616 2.6 1.3 3.5 1.8 1.0

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

SO2 (ppb) 1369 7.7 2.7 10.6 7.0 0.1

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

SO2 (ppb) 1093 10.0 5.6 13.4 6.6 31.0

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

SO2 (ppb) 1552 4.2 2.4 5.4 2.6 0

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

SO2 (ppb) 1520 2.6 1.4 3.3 1.5 0.0

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