Table 4. Non-linear (linear) univariate models with and without spatial autocorrelation for estimating seasonal total concentrations of six PAH species^a.

		Summer		Winter
	Variables	Non-linear (linear) R2	Non-linear (linear) R2 with spatial corr.	Non-linear (linear) R2	Non-linear (linear) R2 with spatial corr.
Emission related
Land-use	Proportion of heavy industrial land-use (4.5 km)	0.10 (0.10)	0.32 (0.32)	0.02 (0.03)	0.54(0.54)
	Proportion of high-density residential land-use (150 m)	0.02 (0.01)	0.10(0.10)	0.08 (0.08)	0.54 (0.54)
	Proportion of agricultural land-use (5 km)	0.01 (0.01)	0.14(0.03)	0.03 (0.02)	0.51 (0.51)
	Proportion of park and recreational land-use (3.5 km)	0.01 (0.01)	0.06 (0.05)	0.25 (0.20)	0.25 (0.21)
Traffic	Shortest distance to freeway (m)	0.06 (0.02)	0.20 (0.20)	0.03 (0.02)	0.70 (0.57)
	Roadway length (700 m buffer; m)	0.11(0.10)	0.03(0.03)	0.02 (0.02)	0.56 (0.56)
	Traffic density (vehicles per km)	0.03 (0.02)	0.25 (0.25)	0.10 (0.07)	0.73 (0.56)
Others	Population density	0.02 (0.01)	0.12 (0.12)	0.01 (0.01)	0.51 (0.51)
	Shortest distance to commercial cooking facilities	0.22 (0.12)	0.28 (0.2)	0.01 (0.01)	0.53 (0.53)
	NDVI (150 m)	0.01 (0.00)	0.13 (0.12)	0.07 (0.06)	0.52 (0.52)
Meteorology
	Temperature (°C)	0.04 (0.01)	0.22 (0.16)	0.08 (0.07)	0.63 (0.63)
	Relative humidity	0.04 (0.04)	0.11 (0.12)	0.26 (0.01)	0.45 (0.46)
	Wind speed (m/s)	0.02 (0.02)	0.27 (0.24)	0.25 (0.01)	0.48 (0.48)

^aTotal PAH included fluorene, phenanthrene, anthracene, acenaphthene, fluoranthene, and pyrene.