ORs from case-crossover analyses between 3-day moving average ZCTA-level pollutant concentrations (per IQR increase) and asthma-related emergency department visits in Atlanta, Georgia, 2002–2008
| Air pollutant | IQR | OR | 95% CI | p Value* |
|---|---|---|---|---|
| O3 | 25 ppb | 1.073 | 1.043 to 1.104 | <0.001 |
| NO2 | 15 ppb | 1.012 | 0.994 to 1.030 | 0.18 |
| PM2.5 | 10 μg/m3 | 1.027 | 1.012 to 1.043 | <0.001 |
| EC | 0.5 μg/m3 | 1.013 | 1.005 to 1.022 | 0.002 |
*Two-sided p value.
EC, elemental carbon fraction of PM2.5; NO2, nitrogen dioxide; O3, ozone; PM2.5, particulate matter <2.5 μm in diameter (fine particulate matter); ZCTA, Zip Code Tabulation Area.