Acute Impact of Hourly Ambient Air Pollution on Preterm Birth

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



Table 4. The risks of preterm birth at 75th and 95th percentiles of air pollution against the minimum preterm birth concentration of air pollution (threshold) in two-pollutant and three-pollutant models.
Model OR (95% CI)
75th vs. threshold 95th vs. threshold
Abbreviations: CI, confidence interval; CO, carbon monoxide (mean of 0–24 hr preceding onset of labor); NO2, nitrogen dioxide (mean of 0–24 hr preceding onset of labor); OR, odds ratio; ppb, parts per billion; SO2, sulfur dioxide (mean of 24–48 hr preceding onset of labor).
NO2
NO2 + SO2 1.01 (0.99, 1.03) 1.17 (1.08, 1.27)
NO2 + CO 1.00 (0.98, 1.02) 1.13 (1.01, 1.26)
NO2 + SO2 + CO 1.00 (0.98, 1.03) 1.13 (1.01, 1.26)
SO2
NO2 + SO2 1.04 (0.99, 1.09) 1.01 (0.99, 1.04)
SO2 + CO 1.04 (0.99, 1.09) 1.01 (0.99, 1.04)
NO2 + SO2 + CO 1.04 (0.99, 1.09) 1.01 (0.99, 1.04)
CO
NO2 + CO 1.07 (0.97, 1.18) 1.11 (0.96, 1.27)
SO2 + CO 1.10 (1.01, 1.19) 1.18 (1.06, 1.32)
NO2 + SO2 + CO 1.07 (0.97, 1.18) 1.11 (0.96, 1.27)