Modeling personal particle-bound polycyclic aromatic hydrocarbon (pb-pah) exposure in human subjects in Southern California

Table 3 Regression model for square root of daily average PB-PAH exposures by subject (N = 180)

	General linear regression					Mixed effect model (fixed effects)
Variable	Beta	Standard error	p-value	Partial R²	VIF	Beta	Standard error	p-value
Intercept	1.54	0.15	<.0001		0	1.55	0.18	<.0001
Percent of in-vehicle travel time	16.90	1.20	<.0001	0.48	1.01	17.40	1.10	<.0001
Length-weighted AADT within 500 m	1.02*10^-5	2.10*10^-6	<.0001	0.08	1.05	0.94*10^-5	3.07*10^-6	0.0027
Had work-related exposure to traffic pollutants (yes/no)^a	0.41	0.15	0.0080	0.02	1.05	0.57	0.27	0.0378
Weekday (1/0)	0.33	0.14	0.0192	0.01	1.01	0.31	0.13	0.0173

^aWork-related exposure includes working around parking garage, kiosk, auto shop, buses, trucks, or heavy traffic, or driving a car/bus/truck during the work.

ISSN: 1476-069X