Table 4.
Mean analyte concentrations and within-child and between-child variances among children participating in the study.
| Analyte | Meana (geometric) | Between-child variance (log) | Within-child variance (log) | Ratio (between-child variance: within-child variance) |
|---|---|---|---|---|
| VOCs (ng/mL) | ||||
| 1,1,1-Trichloroethane | NA | NA | NA | NA |
| 1,4-Dichlorobenzene | 0.16 | 1.79 | 2.05 | 0.87 |
| Benzene | 0.09 | 0.14 | 0.11 | 1.27 |
| Carbon tetrachloride | NA | NA | NA | NA |
| Ethylbenzene | 0.04 | 0.30 | 0.50 | 0.60 |
| m-/p-Xylene | 0.26 | 0.37 | 0.58 | 0.64 |
| o-Xylene | 0.05 | 0.31 | 0.59 | 0.53 |
| Styrene | 0.06 | 0.10 | 0.20 | 0.50 |
| Tetrachloroethylene | 0.04 | 0.40 | 0.44 | 0.91 |
| Toluene | 0.12 | 0.45 | 0.18 | 2.50 |
| Trichloroethene | NA | NA | NA | NA |
| Heavy metals | ||||
| Lead (μg/dL) | 3.08 | 0.95 | 0.32 | 2.97 |
| Hg (μg/L) | 0.23 | 1.11 | 0.58 | 1.91 |
| OC pesticides and related compounds (ng/g-serum) | ||||
| Dieldrin | 0.02 | 0.19 | 0.06 | 3.17 |
| Heptachlor epoxide | 0.02 | 0.32 | 0.04 | 8.00 |
| HCB | 0.04 | 0.10 | 0.02 | 5.00 |
| Mirex | 0.01 | 0.001 | 0.001 | 1.00 |
| Oxychlordane | 0.02 | 1.41 | 0.10 | 14.10 |
| β-HCCH | 0.02 | 1.11 | 0.04 | 27.75 |
| HCCH | 0.01 | 0.001 | 0.001 | 1.00 |
| o,p′-DDT | 0.02 | 0.001 | 0.001 | 1.00 |
| p,p′-DDE | 0.37 | 1.89 | 0.10 | 18.90 |
| p,p′-DDT | 0.03 | 0.27 | 0.09 | 3.00 |
| trans-Nonachlor | 0.02 | 1.40 | 0.14 | 10.00 |
| PCB congeners (ng/g-serum) | ||||
| PCB-66 | 0.04 | 0.90 | 1.23 | 0.73 |
| PCB-74 | 0.03 | 2.07 | 1.37 | 1.51 |
| PCB-87 | 0.01 | 0.94 | 1.02 | 0.92 |
| PCB-99 | 0.02 | 1.91 | 0.52 | 3.67 |
| PCB-101 | 0.01 | 0.89 | 0.72 | 1.24 |
| PCB-105 | 0.01 | 1.03 | 1.21 | 0.85 |
| PCB-110 | 0.01 | 1.15 | 1.17 | 0.98 |
| PCB-118 | 0.02 | 1.48 | 0.20 | 7.40 |
| PCB-128 | 0.01 | 1.00 | 0.98 | 1.02 |
| PCB-138–158 | 0.04 | 1.83 | 0.08 | 22.88 |
| PCB-146 | 0.01 | 1.20 | 0.67 | 1.79 |
| PCB-149 | 0.01 | 1.24 | 1.17 | 1.06 |
| PCB-151 | 0.01 | 1.02 | 0.87 | 1.17 |
| PCB-153 | 0.04 | 2.61 | 0.14 | 18.64 |
| PCB-156 | 0.01 | 1.52 | 1.08 | 1.41 |
| PCB-157 | 0.02 | 0.98 | 0.86 | 1.14 |
| PCB-167 | 0.01 | 1.14 | 1.52 | 0.75 |
| PCB-170 | 0.01 | 1.72 | 0.69 | 2.49 |
| PCB-172 | 0.01 | 1.28 | 1.82 | 0.70 |
| PCB-177 | 0.01 | 0.93 | 1.05 | 0.89 |
| PCB-178 | 0.01 | 1.61 | 1.14 | 1.41 |
| PCB-180 | 0.02 | 2.28 | 0.37 | 6.16 |
| PCB-183 | 0.01 | 0.85 | 0.87 | 0.98 |
| PCB-187 | 0.02 | 1.15 | 0.43 | 2.67 |
| PCB-189 | 0.02 | 1.15 | 0.76 | 1.51 |
| PCB-194 | 0.01 | 1.33 | 0.70 | 1.90 |
| PCB-195 | 0.03 | 1.93 | 0.97 | 1.99 |
| PCB-196–203 | 0.01 | 1.20 | 1.15 | 1.04 |
| PCB-206 | 0.01 | 2.39 | 2.15 | 1.11 |
| PCB-209 | 0.01 | 3.50 | 3.00 | 1.17 |
NA, not applicable (< 10% of VOC samples exceeded the detection limit).
a
Mean refers to the mean of means for each child with more than one sample.