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Table 4 Associations between pollutant concentrations and pediatric asthma emergency department visits per IQR increases in concentration.a

From: Implications of different approaches for characterizing ambient air pollutant concentrations within the urban airshed for time-series studies and health benefits analyses

  Central monitor Unweighted average Population-weighted average
Pollutant RR, 95% CI Chi-square, p-value RR, 95% CI Chi-square, p-value RR, 95% CI Chi-square, p-value
8-h ozone, per IQR 1.065 (1.035, 1.095) χ2 = 18.89, p < 0.001 1.065 (1.036, 1.095) χ2 = 19.47, p < 0.001 1.063 (1.033, 1.094) χ2 = 17.68, p < 0.001
24-h PM10, per IQR 1.024 (1.003, 1.046) χ2 = 4.82, p = 0.028 1.024 (1.002, 1.046) χ2 = 4.40, p = 0.036 1.020 (0.998, 1.041) χ2 = 3.31, p = 0.069
24-h PM2.5, per IQR 1.031 (1.006, 1.056) χ2 = 6.08, p = 0.014 1.039 (1.013, 1.065) χ2 = 8.96, p = 0.003 1.038 (1.012, 1.065) χ2 = 8.28, p = 0.004
24-h PM2.5 sulfate, per IQR 1.026 (1.002, 1.051) χ2 = 4.63, p = 0.031 1.030 (1.005, 1.056) χ2 = 5.64, p = 0.018 1.028 (1.003, 1.053) χ2 = 4.93, p = 0.026
24-h PM2.5 organic carbon, per IQR 1.021 (0.997, 1.045) χ2 = 3.05, p = 0.081 1.038 (1.012, 1.065) χ2 = 8.39, p = 0.004 1.029 (1.005, 1.054) χ2 = 5.43, p = 0.020
24-h PM2.5 elemental carbon, per IQR 1.026 (1.005, 1.047) χ2 = 6.22, p = 0.013 1.025 (1.006, 1.044) χ2 = 6.55, p = 0.010 1.034 (1.009, 1.060) χ2 = 6.97, p = 0.008
1-h nitrogen dioxide, per IQR 1.051 (1.027, 1.076) χ2 = 17.98, p < 0.001 1.053 (1.029, 1.077) χ2 = 19.81, p < 0.001 1.052 (1.030, 1.074) χ2 = 22.30, p < 0.001
1-h carbon monoxide, per IQR 1.037 (1.016, 1.058) χ2 = 12.17, p < 0.001 1.038 (1.014, 1.063) χ2 = 9.80, p = 0.002 1.043 (1.018, 1.069) χ2 = 11.32, p = 0.001
1-h sulfur dioxide, per IQR 1.009 (0.992, 1.027) χ2 = 1.18, p = 0.277 1.023 (1.006, 1.042) χ2 = 6.60, p = 0.010 1.020 (1.001, 1.039) χ2 = 4.48, p = 0.034
  1. Abbreviations: interquartile range (IQR), rate ratio (RR), confidence interval (CI), hour (h), parts per billion (ppb), micrograms per cubic meter (μg/m3), parts per million (ppm).
  2. aRate ratios are for three-day moving average (average of lag 0, lag 1, and lag 2) pollutant concentrations during the six warmest months in Atlanta (May through October).