Skip to main content
. 2013 Mar 5;121(5):543–550. doi: 10.1289/ehp.1205821

Table 3.

Estimated variance components from the random-effects model (model 1a) with corresponding variance ratios.

PAH Variance component estimate (95% CI) Variance ratiob ORBiasedc Percent of total variance
Between- region Intraregional between-household Within- household over time Within- sample analytical Between-region Intraregional between-household Within-household over time Within-sample analytical
Phenanthrene 0.004 (–0.01, 0.02) 0.14 (0.05, 0.23) 0.23 (0.12, 0.35) 0.19 (0.10, 0.27) 3.0 1.2 0.8 24 41 33.0
Anthracene 0.02 (–0.02, 0.06) 0.14 (0.06, 0.22) 0.30 (0.17, 0.42) 0.12 (0.04, 0.20) 2.7 1.2 3.5 24 52 21.0
Fluoranthene 0.02 (–0.02, 0.06) 0.26 (0.17, 0.35) 0.26 (0.18, 0.35) 0.06 (0.001, 0.12) 1.2 1.4 3.2 43 44 10.0
Pyrene 0.02 (–0.01, 0.04) 0.15 (0.09, 0.21) 0.25 (0.20, 0.31) 0.02 (0.02, 0.03) 1.6 1.3 3.7 34 57 5.1
Benzo[a]anthracene 0.04 (–0.03, 0.11) 0.32 (0.20, 0.44) 0.46 (0.36, 0.56) 0.04 (0.03, 0.06) 1.4 1.3 4.4 37 53 5.2
Chrysene 0.02 (–0.02, 0.07) 0.24 (0.16, 0.32) 0.31 (0.25, 0.37) 0.01 (0.01, 0.02) 1.2 1.4 4.2 41 53 2.1
Benzo[b]fluoranthene 0.03 (–0.03, 0.10) 0.37 (0.26, 0.48) 0.34 (0.27, 0.42) 0.02 (0.02, 0.03) 0.9 1.4 4.3 48 45 3.2
Benzo[k]fluoranthene 0.04 (–0.04, 0.11) 0.39 (0.28, 0.51) 0.36 (0.28, 0.44) 0.03 (0.02, 0.04) 0.9 1.4 4.6 48 44 4.2
Benzo[a]pyrene 0.05 (–0.04, 0.14) 0.39 (0.27, 0.52) 0.42 (0.33, 0.52) 0.05 (0.04, 0.07) 1.1 1.4 5.5 43 46 5.6
Indeno[1,2,3-c,d]pyrene 0.05 (–0.04, 0.14) 0.38 (0.26, 0.50) 0.41 (0.32, 0.49) 0.03 (0.02, 0.04) 1.0 1.4 6.2 43 47 3.5
Dibenzo[a,h]anthracene 0.05 (–0.03, 0.12) 0.29 (0.18, 0.40) 0.43 (0.34, 0.53) 0.04 (0.03, 0.05) 1.4 1.3 5.7 36 54 4.6
Benzo[g,h,i]perylene 0.06 (–0.02, 0.14) 0.26 (0.18, 0.34) 0.29 (0.23, 0.35) 0.02 (0.01, 0.02) 1.0 1.4 9.2 42 46 2.5
PAHs are ordered by molecular weight from lightest to heaviest. aModel 1 was fit for 590 observations including 405 samples collected from 204 homes during repeat sampling rounds, 89 samples from homes that were sampled once, 56 duplicate samples, and 40 interbatch quality control replicates. bλ = (σˆ2WH + σˆ2WS)/(σˆ2BR + σˆ2BH). cORBiased = exp [ln(ORTrue)/(1 + λ)], ORTrue = 2.0.