Table 5

Association between exposure variables and emergency department asthma visits for Seattle5-159

Increase RR5-150 95% confidence interval Correlation between exposure variables
Single pollutant
 Stagnation5-160 9.5 hours1.211.09 to 1.35
 PM10 11.7 μg/m3 1.111.02 to 1.20
 Carbon monoxide0.58 ppm1.111.03 to 1.19
 Sulphur dioxide5-165 12 ppb1.020.96 to 1.10
Multi-pollutant
 PM10 11.7 μg/m3 1.030.93 to 1.140.54
 Stagnation5-160 9.5 hours1.191.04 to 1.35
 Carbon monoxide0.58 ppm1.010.91 to 1.130.64
 Stagnation5-160 9.5 hours1.201.03 to 1.39
 Sulphur dioxide5-165 12 ppb1.020.95 to 1.090.07
 Stagnation5-160 9.5 hours1.211.09 to 1.35

  • ↵5-159 Data from Young Pong.21

  • ↵5-150 Relative rates reported for a three day lag; units are interquartile range (25th–75th percentile).

  • ↵5-160 Stagnation persistence index (see text).

  • ↵5-165 Maximum daily one hour average.