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Table 2 Descriptive statistics of air pollutant measurements

From: Associations between microvascular function and short-term exposure to traffic-related air pollution and particulate matter oxidative potential

  N (Missing) Mean (SD) IQR Min Max
Personal Exposures (7-day average)
 NOx (ppb) 729 (116) 28.07 (19.66) 20.87 2.21 160.13
Ambient Exposures (24h Averages)
 Black Carbon (μg/m3) 320 (16) 1.28 (0.85) 1.06 0.21 5.21
 PM2.5 (μg/m3) 309 (27) 17.56 (7.70) 9.62 3.83 49.23
 CO (ppm) 311 (25) 0.54 (0.24) 0.32 0.11 1.59
 Ozone (ppb) 303 (33) 23.16 (9.25) 12.66 1.33 48.51
 NOx (ppb) 241 (95) 35.42 (27.69) 31.02 3.6 175.63
 Heat Index (F°) 366 (0) 66.09 (8.39) 12.56 42.57 84.33
Size-fractionated PM (5-day average)
 Mass (μg/m3)
  PM0.18 45 (3) 2.41 (0.86) 1.13 1.17 4.81
  PM0.18 – PM2.5 45 (3) 8.64 (3.21) 4.01 4.40 19.43
  PM2.5 – PM10 44 (4) 14.91 (6.78) 7.80 4.45 35.36
 Total PAH (ng/m3)
  PM0.18 45 (3) 0.32 (0.22) 0.30 0.03 0.77
  PM0.18 – PM2.5 45 (3) 0.46 (0.45) 0.46 0.21 1.98
 Hopanes (ng/m3)
  PM0.18 45 (3) 0.17 (0.12) 0.19 0.01 0.44
  PM0.18 – PM2.5 45 (3) 0.21 (0.20) 0.21 0.00 0.82
 OA (μg/m3)
  PM0.18 45 (3) 26.21 (10.84) 14.45 9.64 57.98
  PM0.18 – PM2.5 45 (3) 18.12 (13.99) 16.76 0.56 61.43
 OC (μg/m3)
  PM0.18 45 (3) 1.18 (0.39) 0.42 0.47 2.35
  PM0.18 – PM2.5 45 (3) 1.54 (0.78) 1.11 0.53 3.48
  PM2.5 – PM10 45 (3) 0.67 (0.22) 0.30 0.28 1.12
 EC (μg/m3)
  PM0.18 45 (3) 0.26 (0.13) 0.16 0.09 0.60
  PM0.18 – PM2.5 45 (3) 0.15 (0.12) 0.18 0.01 0.45
  PM2.5 – PM10 45 (3) 0.04 (0.03) 0.05 0.00 0.09
 Total ROS (μg Zym/m3)a
  PM0.18 45 (3) 19.8 (12.21) 16.60 2.10 53.20
  PM0.18 – PM2.5 45 (3) 136.69 (94.62) 125.90 26.20 394.00
  PM2.5 – PM10 44 (4) 60.19 (49.73) 76.45 8.70 181.00
 Water-soluble ROS (μg Zym/m3)
  PM0.18 45 (3) 16.74 (11.49) 13.60 1.50 50.60
  PM0.18 – PM2.5 45 (3) 117.05 (87.66) 95.60 18.60 421.90
  PM2.5 – PM10 44 (4) 25.04 (22.63) 34.05 2.40 84.20
 Dithiothreitol (nmol/min/m3)
  PM0.18 45 (3) 0.10 (0.05) 0.06 0.02 0.24
  PM0.18 – PM2.5 45 (3) 0.26 (0.08) 0.08 0.12 0.48
  PM2.5 – PM10 44 (4) 0.24 (0.11) 0.14 0.10 0.53
 Transition metalsb (ng/m3)
  PM0.18 45 (3) 49.20 (40.43) 56.2438 7.22 153.39
  PM0.18 – PM2.5 45 (3) 72.02 (52.86) 46.0233 12.89 237.11
  PM2.5 – PM10 44 (4) 396.57 (171.18) 219.9526 111.97 914.57
  1. Abbreviations: IQR interquartile range, CO carbon monoxide, PM particulate matter, PAHs polycyclic aromatic hydrocarbons, OC organic carbon, EC elemental carbon, ROS Reactive oxygen species
  2. aZym: μg Zymosan equivalent units
  3. bTotal sum of transition metals include V, Cr, Mn, Ni, Cu and Fe