. 2009 Jun 23;117(10):1571–1579. doi: 10.1289/ehp.0900561

Table 1.

R², R²_adj, SE (μg/m3), NMB, MFB, and FA2 and FA3 in training (TR) and validation (VAL) data sets.

Model/ data set	Hexane	Benzene	Toluene	Ethyl-benzene	p-Xylene	m-Xylene	Pyridine	o-Xylene	1,3,5-Tri- methyl- benzene	Styrene	p-Isopropyl- toluene	1,2,4-Tri- methyl- benzene	3-Ethenyl-pyridine	Naphth-alene	1,3-Buta- diene
Model 1
TR
R²	0.15^a	0.74^a	0.66^a	0.23^a	0.49^a	0.48^a	0.39^a	0.48^a	0.49^a	0.05	0.30^a	0.54^a	0.61^a	0.20^a	0.11^a
R²_adj	0.13^a	0.74^a	0.65^a	0.21^a	0.48^a	0.47^a	0.38^a	0.47^a	0.48^a	0.03	0.29^a	0.54^a	0.61^a	0.19^a	0.09^a
SE	2.65	0.76	8.58	2.28	1.51	3.73	0.20	1.94	1.29	0.33	0.62	3.77	0.31	0.61	36
VAL
R²	0.65^a	0.83^a	0.89^a	0.86^a	0.69^a	0.59^a	0.71^a	0.63^a	0.94^a	0.86	0.47^a	0.95^a	0.98^a	0.65^a	0.02^a
NMB (%)	−25	0	5	−18	7	2	−4	6	12	−47	17	7	4	8	−45
MFB (%)	7	7	33	34	34	29	23	29	−12	52	25	15	60	29	−47
FA2 (%)	35	100	65	65	75	60	75	70	75	45	80	80	60	75	15
FA3 (%)	65	100	85	85	85	90	90	85	85	85	95	100	70	100	20

Model 2
TR
R²	0.10	0.12	0.17	0.05	0.08	0.06	0.00	0.07	0.01	0.01	0.05	0.01	0.01	0.04	0.05
R²_adj	0.07	0.10	0.14	0.02	0.05	0.03	0.03	0.04	−0.01	−0.01	0.03	−0.02	−0.01	0.01	0.02
SE	2.99	1.44	12.9	1.73	1.97	4.6	0.22	2.27	1.08	0.32	0.47	3.87	0.34	0.74	0.21
VAL
R²	0.28	0.17	0.18	0.70	0.25	0.69^a	0.00	0.23	0.48^a	0.28	0.01	0.32	0.03	0.31	0.00
NMB (%)	−2	9	14	35	56	37	−16	61	70	4	17	77	−34	38	−35
MFB (%)	41	14	30	43	50	43	48	50	62	14	29	69	46	38	38
FA2 (%)	50	88	75	75	63	75	75	63	50	88	75	38	50	75	25
FA3 (%)	63	100	75	88	88	88	75	88	50	100	88	63	75	100	38

Model 3
TR
R²	0.17	0.74^a	0.65^a,^b	0.38^a	0.39^a,^b	0.37^a	0.21^a	0.36^a,^b	0.44^a	0.27^a	0.39^a	0.49^a	0.43^a	0.04	0.56^a
R²_adj	0.12	0.72^a	0.63^a,^b	0.34^a	0.36^a,^b	0.33^a	0.16^a	0.32 ^a,^b	0.41^a	0.23^a	0.35^a	0.46^a	0.39^a	−0.01	0.52^a
SE	2.97	0.82	8.70	1.45	1.65	3.90	0.21	1.96	0.86	0.28	0.39	2.91	0.27	0.78	0.15
VAL
R²	0.34	0.25	0.67^a	0.93^a	0.57^a	0.91^a	0.37	0.54^a	0.81^a	0.37	0.05	0.83^a	0.93^a	0.67^a	0.85^a
NMB (%)	−5	−1	4	23	36	25	2	37	21	−1	−2	20	−1	31	−33
MFB (%)	40	4	21	36	38	35	60	36	27	7	12	29	66	38	31
FA2 (%)	50	88	75	75	63	75	63	75	88	88	75	100	63	75	38
FA3 (%)	50	100	88	88	100	88	75	100	100	100	100	100	75	100	38

Model 4
TR
R²	0.51^a	0.44^a	0.53^a	0.56^a	0.63^a	0.60^a	0.24^a	0.63^a	0.62^a	0.79^a	0.43^a	0.67^a	0.30^a	0.79^a	0.12^a
R²_adj	0.51^a	0.44^a	0.52^a	0.56^a	0.63^a	0.60^a	0.24^a	0.63^a	0.62^a	0.79^a	0.43^a	0.67^a	0.30^a	0.79^a	0.12^a
SE	1.24	0.89	11.30	0.89	0.91	2.19	0.22	0.98	0.33	0.38	0.35	1.23	0.26	0.38	0.28
VAL
R²	0.02	0.16	0.19	0.03	0.00	0.01	0.27	0.00	0.03	0.03	0.02	0.07	0.32	0.00	0.02
NMB (%)	−25	−21	−1	−18	−22	−20	−19	−29	−10	−22	−14	−19	−24	10	−27
MFB (%)	−37	−18	9	−48	−45	−45	−20	−47	−33	24	20	−38	−33	−34	106
FA2 (%)	39	81	73	66	57	58	56	59	58	66	72	56	49	74	33
FA3 (%)	58	97	90	82	75	74	78	78	78	93	88	81	72	90	52

Model 5
TR
R²	0.02	0.16^a	0.11^a	0.07^a	0.13^a	0.13^a	0.19^a	0.15^a	0.20^a	0.28^a	0.05	0.32^a	0.26^a	0.13^a	0.08
R²_adj	0.01	0.16^a	0.11^a	0.07^a	0.12^a	0.12^a	0.19^a	0.15^a	0.19^a	0.28^a	0.04	0.31^a	0.26^a	0.13^a	0.07
SE	1.13	0.98	9.81	0.94	1.08	2.60	0.22	1.34	0.33	0.64	0.26	1.28	0.25	0.47	0.41
VAL
R²	0.27	0.06	0.12	0.08	0.14	0.11	0	0.1	0.16	0.05	0	0.02	0	0.11	0.06
NMB (%)	−30	−16	−23	−16	−27	−23	−20	−26	−30	−11	−21	2	−29	−19	26
MFB (%)	−27	−16	−19	−27	−42	−39	−50	−44	−30	27	14	14	3	−25	119
FA2 (%)	44	74	51	61	55	52	64	51	58	70	64	54	56	65	31
FA3 (%)	63	88	70	76	73	72	86	74	77	88	83	77	68	83	44

Model 6
TR
R²	0.39^a	0.47^a	0.51^a	0.81^a	0.82^a	0.83^a	0.70^a	0.83^a	0.79^a	0.87^a	0.48^a	0.86^a	0.75^a	0.42^a	0.49^a
R²_adj	0.38^a	0.45^a	0.50^a	0.81^a	0.82^a	0.83^a	0.70^a	0.81^a	0.78^a	0.87^a	0.47^a	0.81^a	0.75^a	0.41^a	0.48^a
SE	2.85	0.97	12.31	1.43	1.42	3.39	0.23	1.67	1.24	1.18	0.72	3.31	0.34	0.9	0.39
VAL
R²	0.48^a	0.44^a	0.53^a	0.64^a	0.62^a	0.52^a	0.66^a	0.62^a	0.71^a	0.94^a	0.36^a	0.83^a	0.61^a	0.06	0.08
NMB (%)	−25	−20	−7	−10	−15	−23	−6	14	−22	8	−6	−28	−39	17	−40
MFB (%)	44	−8	14	6	11	4	25	41	−24	16	13	−7	16	23	27
FA2 (%)	43	80	61	73	69	66	63	56	49	57	76	60	42	64	31
FA3 (%)	61	92	83	87	90	87	75	84	72	84	91	83	62	84	49

Model 7
TR
R²	0.13^a	0.09^a	0.02^a	0.01	NVE	0.01	0.22^a	0.02	0.04^a	0.01	NVE	0.05^a	0.27^a	0.05^a	0.09^a
R²_adj	0.12^a	0.08^a	0.02^a	0.01	NVE	0.01	0.21^a	0.01	0.04^a	0.01	NVE	0.04^a	0.27^a	0.04^a	0.09^a
SE	3.38	1.25	17.17	3.25	NVE	8.16	0.36	4.46	2.61	3.21	NVE	7.42	0.59	1.16	0.5
VAL
R²	0.08	0.18	0.05	0.00	0.03	0.05	0.00	0.03	0.01	0.01	0.01	0.04	0.44	0.05	0.01
NMB (%)	−31	−21	1	−96	140	−94	768	−56	45	144	−52	−70	−7	−22	23
MFB (%)	15	−10	12	−92	80	−153	163	−38	36	92	−93	−60	53	−28	67
FA2 (%)	37	87	57	39	13	1	1	43	33	24	28	55	39	48	45
FA3 (%)	67	94	79	54	30	9	6	70	61	34	37	75	55	81	63

NVE, no variable entered in the stepwise regression. Sample sizes (training/validation data sets): model 1, 58/19; models 2 and 3, 40/10; models 4–7, 370/120.

Represent significant correlation values at 0.01 level.

The workplace concentration coefficient γ is significant at the 0.01 level.