Table 3.

Estimated variance components for major PCBs from the random-effects model (Model 1^a) with corresponding variance ratios.

	Variance Component Estimate (95% Confidence Interval)						Percent of Total Variance
PCB	Between-region, ${\widehat{\sigma }}_{BR}^2$	Intra-regional between-home, ${\widehat{\sigma }}_{BH}^2$	Within-home over time, ${\widehat{\sigma }}_{WH}^2$	Within-sample, ${\widehat{\sigma }}_{WS}^2$	λ b	OR Exp c	$\frac{{\widehat{\sigma }}_{BR}^2}{{\widehat{\sigma }}_{Total}^2}$	$\frac{{\widehat{\sigma }}_{BH}^2}{{\widehat{\sigma }}_{Total}^2}$	$\frac{{\widehat{\sigma }}_{WH}^2}{{\widehat{\sigma }}_{Total}^2}$	$\frac{{\widehat{\sigma }}_{WS}^2}{{\widehat{\sigma }}_{Total}^2}$
PCB-28	0.04 (0.01, 0.49)	0.22 (0.16, 0.34)	0.33 (0.26, 0.42)	0.07 (0.05, 0.09)	1.5	1.3	6	34	50	10
PCB-52	0.07 (0.02, 0.77)	0.42 (0.33, 0.56)	0.27 (0.21, 0.36)	0.10 (0.08, 0.13)	0.8	1.5	8	49	32	11
PCB-101	0.16 (0.06, 1.68)	0.81 (0.66, 1.04)	0.31 (0.23, 0.43)	0.16 (0.12, 0.21)	0.5	1.6	11	56	21	11
PCB-105	0.15 (0.05, 1.93)	0.97 (0.78, 1.24)	0.31 (0.21, 0.51)	0.28 (0.22, 0.38)	0.5	1.6	9	56	18	16
PCB-118	0.18 (0.06, 1.96)	0.89 (0.71, 1.14)	0.41 (0.32, 0.55)	0.14 (0.11, 0.19)	0.5	1.6	11	55	25	9
PCB-138	0.08 (0.03, 1.23)	0.32 (0.21, 0.52)	0.60 (0.48, 0.78)	0.16 (0.13, 0.22)	1.9	1.3	7	27	52	14
PCB-153	0.14 (0.05, 1.55)	0.78 (0.62, 1.00)	0.34 (0.26, 0.48)	0.15 (0.12, 0.21)	0.5	1.6	10	55	24	11
PCB-180	0.13 (0.04, 1.94)	0.75 (0.59, 0.99)	0.35 (0.25, 0.52)	0.23 (0.18, 0.32)	0.7	1.5	9	52	24	16

^aIn this table, Model 1 was fit for 585 observations including 402 samples collected from 201 homes during repeat sample collections, 88 samples from homes that were sampled once, 55 duplicate samples, and 40 inter-batch quality control replicates.

^bEstimated variance ratio, $\lambda =\frac{{\widehat{\sigma }}_{WH}^2+{\widehat{\sigma }}_{WS}^2}{{\widehat{\sigma }}_{BR}^2+{\widehat{\sigma }}_{BH}^2}$

^cExpected odds ratio, $O{R}_{Expected}=\exp \left[\frac{ln\left(O{R}_{True}\right)}{1+\lambda }\right]$