Table 2.

Airborne data collection and prediction by location and monitoring period: A) Summary of strata by location and monitoring period, B) Year of monitoring predicts PAH, BC and PM_2.5

A.
Location	Outdoora	Indoorb
Monitoring periods	2006–2012	2005–2012	2001–2012
Age group(s)	5/6 - 9/10 yrs	5/6 - 9/10 yrs	Prenatal - 9/10 yrs
Number of observations	195	527c	623d
# of repeat subjects (≥2)	28	62	136

B.
Location	Outdoora	Indoorb
Monitoring periods	2006–2012	2005–2012	2001–2012
	Annual percent change (APC), [%]
eΣ8PAHsemivolatile	0.70	7.90**	-
PYR	3.77*	4.81**	−2.76**
fΣ8PAHnonvolatile	−1.98	−0.70	−4.21**
BC	−2.08	−2.08*	-
PM2.5	−5.35**	−2.18	-

-: Not available. Data were natural-log transformed and annual percent change in air pollutant concentration was calculated by 100*[exp(log_β_adj)−1] where log_β_adj expressed in log-adjusted ng·m⁻³/year for PAHs and log-adjusted μg·m⁻³/year for BC and PM_2.5;

^aGeneralized Estimating Equation (GEE) conducted after controlling for moved (defined as change of addresses between age 5 and 9 years), heat season and ambient ozone;

^bGEE analysis conducted after controlling for race/ethnicity, maternal education, current ETS exposure, gas stove cooking, housing crowding (defined as the number of people living in the house), heat season and ambient ozone.

^cReduced by n=13 and

^dReduced by n=15 due to missing covariates;

^eΣ₈PAH_semivolatile: PYR, PHEN, 1-MEPH, 2- MEPH, 3- MEPH, 9-MEPH, 1,7-DMEPH, and 3,6-DMEPH;

^fΣ₈PAH_nonvolatile: BaA, BbFA, BkFA, BaP, BghiP, Chry, DahA and IP; boldface type indicates statistical significance with *p-value<0.05 and **p-value<0.01.