Acute Impact of Hourly Ambient Air Pollution on Preterm Birth

http://dx.doi.org/10.1289/EHP200



Table 2. Summary statistics of hourly air pollution and weather conditions during 2009–2013 in Brisbane, Australia.
Variables Mean ± SD Percentile
5th 25th 50th 75th 95th
Abbreviations: CO, carbon monoxide; NO2, nitrogen dioxide; O3, ozone; PM2.5, particulate matter ≤ 2.5 μm in diameter; PM10, particulate matter ≤ 10 μm in diameter; ppb, parts per billion; SD, standard deviation; SO2, sulfur dioxide. 
PM2.5 (μg/m3) 6.32 ± 4.05 3.20 4.35 5.55 7.24 11.10
PM10 (μg/m3) 17.27 ± 15.33 9.78 13.08 15.79 18.94 26.29
NO2 (ppb) 6.52 ± 3.50 2.47 4.00 5.58 8.25 13.63
SO2 (ppb) 1.95 ± 3.26 0.42 0.75 1.15 2.00 5.36
O3 (ppb) 17.27 ± 8.59 5.33 10.56 16.11 23.00 32.89
CO (ppb) 219.30 ± 135.53 50.00 120.00 200.00 300.00 450.00
Temperature (°C) 21.97 ± 4.83 13.25 18.78 22.48 25.46 29.24
Relative humidity (%) 70.82 ± 14.31 44.99 60.66 73.18 82.34 90.16