Table 1.

Ambient concentrations of pollutants at Iowa City background and tire fire plume-impacted levels and fuel-based emission factors.

		Ambient Concentrations			Emission Factors (g kg−1 or # kg−1)
	Formula	Background	Plume-impacted	Units	Mean	Std. Deviation	Median
Carbon dioxidea	CO2	378.9	383.1	(ppm)	-	-	-
Sulfur dioxidea	SO2	1.69	3.75	(ppb)	7.1	8.31	2.91
PM2.5a	-	9.81	15.1	(μg m−3)	5.35	5.39	3.05
Elemental carbon	-	0.22b	0.84c	(μg m−3)	2.41	2.43	1.37
Particle numbera	-	9800	39400	(# cm−3)	3.49E+16	3.41E+16	2.05E+16
Polycyclic aromatic hydrocarbonsd					(mg kg−1)	(mg kg−1)	(mg kg−1)
9-Methylanthracene	C15H12	BDLe	0.07c	(ng m−3)	0.35	0.19	0.24
Fluoranthene	C16H10	0.06	0.60	(ng m−3)	0.67	0.80	0.31
Acephenanthrylene	C16H10	BDL	0.31	(ng m−3)	0.49	0.43	0.31
Pyrene	C16H10	0.02	0.64	(ng m−3)	0.70	0.34	0.52
Benzo[ghi]fluoranthene	C18H10	BDL	0.64	(ng m−3)	1.6	0.5	1.4
Cyclopenta[cd]pyrene	C18H10	0.08	0.39	(ng m−3)	0.65	0.34	0.54
Benz[a]anthracene	C18H12	0.02	1.45	(ng m−3)	1.8	2.2	0.88
Chrysene	C18H12	0.07	5.44	(ng m−3)	8.3	8.0	4.4
Retene	C18H18	BDL	0.61	(ng m−3)	0.90	0.96	0.45
1-Methylchrysene	C19H14	BDL	0.69	(ng m−3)	1.2	0.9	0.9
Benzo[b+k]fluoranthene	C20H12	0.16	9.82	(ng m−3)	17	13	11
Benzo[j]fluoranthene	C20H12	BDL	0.94	(ng m−3)	1.1	1.4	0.48
Benzo[e]pyrene	C20H12	0.18	5.70	(ng m−3)	9.8	7.6	6.7
Benzo[a]pyrene	C20H12	0.02	1.56	(ng m−3)	2.3	2.2	1.5
Perylene	C20H12	0.02	0.21	(ng m−3)	0.35	0.26	0.25
Indeno[1,2,3-cd]pyrene	C22H12	0.05	1.65	(ng m−3)	2.9	2.1	1.8
Benzo[ghi]perylene	C22H12	0.06	1.66	(ng m−3)	3.4	2.1	2.6
Dibenz[ah]anthracene	C22H14	BDL	0.53	(ng m−3)	1.1	0.65	0.77
Picene	C22H14	BDL	0.58	(ng m−3)	1.6	0.68	1.2
Sum of quantified PAH	-	-	33.4	(ng m−3)	56	44	37

^aDetermined from samples collected 30 May to 3 June, 2012 (n = 10)

^bMay-June 2011 background (n=28)

^cgreatest plume-impact on June 2, 2012 (n=1)

^dEF determined from samples collected 28 May to 5 June, 2012 (n = 5)

^epre-tire fire May 24, 2012 levels (n=1).