Table 4

Final model results for three pollutants



ln(PM2.5) (μg/m3)
ln(EC) (m-1*10-5)
NO2 (ppb)
Predictor Type
Model
β (p-value)
Sequential R2
Model
β (p-value)
Sequential R2
Model
β (p-value)
Sequential R2

Intercept

0.205 (.32)
--

-0.907 (<.0001)
--

-12.50 (.009)
--
Central site Concentration
ln (Central Site [PM2.5])
0.776 (<.0001)
.68
ln (Central site [EC])
0.103 (.59)
.03
Central site [NO2]
1.06 (<.0001)
.21




ln (Central site [EC]) * warmer season
0.82 (.004)
.26



Traffic Indicator
Roadway Length in 100 m
1.48*10-4 (.02)
.70
Roadway Length in 200 m
1.10 * 10-4 (.01)
.40
Roadway Length in 50 m
0.0144 (.002)
.22
Traffic Indicator* Modifier
N/A
N/A
N/A
Roadway Length in 200 m × % Hours of Still Winds
4.38 *10-4 (.02)
.48
Roadway Length in 50 m × Obstructed Major Rd
-0.0094 (.005)
.31
Other Sources/Land Use
Smoking or grilling
0.156 (.01)
.73
Warmer Season
-0.268 (.057)
.52
Warmer Season
4.93 (.001)
.44

Population Density
9.24*10-6 (.01)
.76



Population Density
4.01*10-4 (.001)
.56

Clougherty et al. Environmental Health 2008 7:17   doi:10.1186/1476-069X-7-17