Table 1.

Summary of on-bus measurements of integrated gravimetric and continuous data. N represents the number of integrated samples or 1-min measurements. Differences between buses 1 and 2 or window configurations are shown in the last column.

Measure	Bus	Window	N	Mean	Std	Min	Max	Difference (range)
PM1 (μg/m3)	1		8	11	5	7	19	3 (−2,8)
	2		8	8	5	3	14
	Both	C	8	14	3	10	19	8 (5,11)‡
		O	8	5	2	3	8
	Both		16	10	5	3	19
PM2.5 (μg/m3) from UMD	1		8	25	16	14	61	6 (−9,20)
	2		8	19	11	3	34
	Both	C	8	32	13	19	61	19 (8,29)⧧
		O	8	13	5	3	18
	Both		16	22	14	3	61
pDR (μg/m3)	1		511	34	31	6	210	−24 (−29, −19)‡
	2		288	58	41	6	224
	Both	C	473	58	40	6	224	37 (32,42)‡
		O	326	20	14	6	203
	Both		799	43	37	6	224
UPM (#/cm3) from P-TRAK (PT)	1		341	44587	43153	5611	169948	19387 (15118,23657)‡
	2		497	25200	18340	2069	158783
	Both	C	460	26336	22013	5611	159366	−14970 (−19262, −10678)‡
		O	378	41306	40128	2069	169948
	Both		838	33089	32351	2069	169948
PAH (ng/m3) from GC/MS	1		4	1.1	0.5	0.6	1.7	−1.1 (−2.6,0.5)
	2		4	2.1	1.2	1.0	3.3
	Both	C	4	2.3	1.0	1.2	3.3	1.4 (0.1,2.6)†
		O	4	0.9	0.3	0.6	1.3
	Both		8	1.6	1.0	0.6	3.3
PAH (ng/m3) from PAS	1		659	44	39	0	193	−18 (−23, −13)‡
	2		504	61	47	0	440
	Both	C	615	54	42	0	259	6 (1,11)†
		O	548	48	45	0	440
	Both		1163	51	43	0	440
EC (μg/m3) from aethalometer	1		602	1.1	0.8	−0.2	8.8	−1.7 (−1.8, −1.5)‡
	2		478	2.8	2.1	−0.1	15.1
	Both	C	583	2.5	1.8	−0.2	7.6	1.3 (1.1,1.5)‡
		O	497	1.1	1.4	−0.1	15.1
	Both		1080	1.9	1.7	−0.2	15.1
EC (μg/m3) from photoacoustic	1		618	0.5	0.5	−0.1	7.2	−0.9 (−0.9, −0.8)‡
	2		504	1.3	1.0	−0.1	8.1
	Both	C	574	1.2	0.9	−0.1	3.3	0.7 (0.6,0.8)‡
		O	548	0.5	0.7	−0.1	8.1
	Both		1122	0.9	0.9	−0.1	8.1
EC (μg/m3) from TOR	1		4	1.9	0.6	1.3	2.7	−1.5 (−3.6,0.5)
	2		4	3.5	1.5	1.8	5.2
	Both	C	4	3.6	1.4	2.1	5.2	1.3 (−0.1,3.6)
		O	4	1.8	0.6	1.3	2.7
	Both		8	2.7	1.4	1.3	5.2
OC (μg/m3) from TOR	1		4	13.9	5.7	6.6	20.6	−1.9 (−11.4,11.3)
	2		4	13.9	7.3	6.5	23.1
	Both	C	4	18.6	3.9	14.6	23.1	9.4 (3.0,15.8)†
		O	4	9.2	3.5	6.5	13.9
	Both		8	13.9	6.1	6.5	23.1

^†p<0.05,

^⧧p<0.01,

^‡p<0.001