Table 2.
Percentage Change in All-Cause Mortality in Association with an Increase of 10 μg per Cubic Meter in the 2-Day Moving Average Concentrations of PM10 and PM2.5, with and without Adjustment for Copollutants.*
| Models | PM10 | PM2.5 | ||||
|---|---|---|---|---|---|---|
| Cities with Available Data | Pooled Estimate | P Value for Difference | Cities with Available Data | Pooled Estimate | P Value for Difference | |
| no. | % (95% CI) | no. | % (95% CI) | |||
| PM and ozone | 559 | 0.90 | 487 | 0.75 | ||
| Single-pollutant model of PM | 0.43 (0.37–0.48) | 0.68 (0.58–0.77) | ||||
| Two-pollutant model of PM with adjustment for ozone | 0.43 (0.37–0.49) | 0.66 (0.56–0.77) | ||||
| PM and nitrogen dioxide | 495 | <0.001 | 466 | <0.001 | ||
| Single-pollutant model of PM | 0.43 (0.37–0.49) | 0.66 (0.57–0.76) | ||||
| Two-pollutant model of PM with adjustment for nitrogen dioxide | 0.28 (0.22–0.35) | 0.42 (0.31–0.53) | ||||
| PM and sulfur dioxide | 495 | 0.007 | 466 | 0.007 | ||
| Single-pollutant model of PM | 0.44 (0.38–0.50) | 0.67 (0.57–0.76) | ||||
| Two-pollutant model of PM with adjustment for sulfur dioxide | 0.36 (0.30–0.42) | 0.52 (0.42–0.62) | ||||
| PM and carbon monoxide | 445 | 0.75 | 416 | 0.50 | ||
| Single-pollutant of PM | 0.40 (0.34–0.46) | 0.61 (0.51–0.71) | ||||
| Two-pollutant model of PM with adjustment for carbon monoxide | 0.39 (0.32–0.46) | 0.57 (0.46–0.68) | ||||
*
Pooled estimates are of the percentage change in daily all-cause mortality per 10-μg-cubic-meter increase in PM10 or PM2.5 concentration. The P value for difference was calculated by evaluating a binary variable (with and without the adjustment for the copollutant) in a paired z-test with estimates from both single-pollutant and two-pollutant models. A P value of less than 0.05 was considered to be statistically significant for the difference.