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Table 3 Missing data days and summary statistics of maximum daily pollutant levels in study period.

From: Impact of air pollution on hospital admissions in Southwestern Ontario, Canada: Generating hypotheses in sentinel high-exposure places

Variable (unit) Mean Standard Deviation Minimum/24 hr Maximum/24 hr AAQC Number of Missing Days
SO2 (ppb) London 3.35 2.96 0 28.63   12
  Windsor 7.36 5.06 0 37.50 100/24 hr 8
  Sarnia 9.72 12.72 0 110.17   4
NO2 (ppb) London 18.10 7.86 0 53   54a
  Windsor 23.50 7.59 6 50 100/24 hr 11
  Sarnia 16.85 8.13 0 52   100c
O3 (ppb) London 23.61 12.50 0 77   7
  Windsor 20.62 12.58 0 82 80/hr 6
  Sarnia 25.35 11.86 0 76   54d
CO (ppm) London 0.16 0.30 0 3   9
  Windsor 0.60 0.44 0 3 3/hr 5
  Sarnia 0.27 0.29 0 1.4   87b
  1. Ambient Air Quality Criteria (Ontario Ministry of the Environment, 2000).
  2. a Seven or more missing days in a row: 2000 – Jan. 7–31; Feb. 1–10
  3. b Seven or more missing days in a row: 1998 – Dec 2–31; 1999 – Jan 1–31
  4. c Seven or more missing days in a row: 1997 – Oct. 8–16; 1998 – Sept. 24–30; Oct. 1–31; Nov. 1–10
  5. d Seven or more missing days in a row: 2000 – Nov. 8–16
  6. e Seven or more missing days in a row: 1997 – Jan. 17–23