Table 3.
Racial disparities in blood lead (Pb) level outcomes for risk factor groups of early childhood Pb exposure before and after correcting for covariates in multiple regression model analysis—the 1999 to 2010 NHANES.
| Model | Independent Variable | Sample (%) | BLL (in µg/dL) | EBLL (≥5 µg/dL) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Risk Factor | Mean ± SD | B Coeff. (β) | 95% CI | p-Value | Mean ± SE | Odds Ratio | 95% CI | p-Value | ||
|
Full Model Total Sample |
NH White or Hispanic | 2233 (78.6%) | 1.89 ± 1.78 | Reference | – | – | 5.0% ± 0.5% | Reference | – | – |
| NH Black | 608 (21.4%) | 2.81 ± 2.95 | +0.92 (+0.179) | +0.74 to +1.11 | <0.001 ** | 12.0% ± 1.3% | 2.6 | 1.9 to 3.6 | <0.001 ** | |
| Adjusted a | +0.83 (+0.160) | +0.65 to +1.00 | <0.001 ** | 2.8 | 1.9 to 3.9 | <0.001 ** | ||||
|
Model 1—Age 1 Year of Age |
NH White or Hispanic | 526 (79.1%) | 2.22 ± 2.34 | Reference | – | – | 8.9% ± 1.2% | Reference | – | – |
| NH Black | 139 (20.9%) | 3.51 ± 4.53 | +1.29 (+0.177) | +0.74 to +1.84 | <0.001 ** | 18.0% ± 3.3% | 2.2 | 1.3 to 3.8 | 0.003 ** | |
| Adjusted a,b | +1.00 (+0.136) | +0.47 to +1.53 | <0.001 ** | 2.0 | 1.1 to 3.7 | 0.035 * | ||||
|
Model 2—Age 2 Years of Age |
NH White or Hispanic | 554 (80.8%) | 2.00 ± 1.84 | Reference | – | – | 5.2% ± 0.9% | Reference | – | – |
| NH Black | 131 (19.2%) | 3.45 ± 3.19 | +1.45 (+0.256) | +1.04 to +1.86 | <0.001 ** | 19.8% ± 3.5% | 4.5 | 2.5 to 7.9 | 0.001 ** | |
| Adjusted a,b | +1.41 (+0.249) | +1.01 to +1.81 | <0.001 ** | 5.3 | 2.6 to 10.7 | <0.001 ** | ||||
|
Model 3—Age 3 Years of Age |
NH White or Hispanic | 355 (76.7%) | 1.75 ± 1.47 | Reference | – | – | 3.7% ± 1.0% | Reference | – | – |
| NH Black | 108 (23.3%) | 2.55 ± 1.87 | +0.80 (+0.211) | +0.46 to +1.14 | <0.001 ** | 10.2% ± 2.9% | 3.0 | 1.3 to 6.9 | 0.007 ** | |
| Adjusted a,b | +0.73 (+0.192) | +0.40 to +1.06 | <0.001 ** | 4.7 | 1.7 to 13.1 | 0.003 ** | ||||
|
Model 4—Education Primary Guardian <12th Grade/GED |
NH White or Hispanic | 624 (82.3%) | 2.17 ± 2.12 | Reference | – | – | 6.3% ± 1.0% | Reference | – | – |
| NH Black | 134 (17.7%) | 3.49 ± 2.67 | +1.32 (+0.221) | +0.90 to +1.74 | <0.001 ** | 20.9% ± 3.5% | 4.0 | 2.3 to 6.7 | <0.001 ** | |
| Adjusted a,c | +0.99 (+0.166) | +0.58 to +1.40 | <0.001 ** | 3.5 | 1.8 to 6.7 | <0.001 ** | ||||
|
Model 5—Housing Housing Built 1950 to 1977 |
NH White or Hispanic | 727 (76.9%) | 1.78 ± 1.36 | Reference | – | – | 3.0% ± 0.6% | Reference | – | – |
| NH Black | 218 (23.1%) | 2.90 ± 2.52 | +1.12 (+0.268) | +0.86 to +1.38 | <0.001 ** | 12.8% ± 2.3% | 4.7 | 2.6 to 8.4 | <0.001 ** | |
| Adjusted a,d | +1.02 (+0.244) | +0.76 to +1.27 | <0.001 ** | 5.6 | 2.8 to 11.2 | <0.001 ** | ||||
|
Model 6—Housing Housing Built <1950 |
NH White or Hispanic | 506 (82.4%) | 2.73 ± 2.71 | Reference | – | – | 13.4% ± 1.5% | Reference | – | – |
| NH Black | 108 (17.6%) | 4.43 ± 5.32 | +1.70 (+0.192) | +1.01 to +2.40 | <0.001 ** | 26.9% ± 4.3% | 2.4 | 1.4 to 3.9 | 0.001 ** | |
| Adjusted a,d | +1.22 (+0.138) | +0.54 to +1.90 | <0.001 ** | 1.8 | 1.0 to 3.2 | 0.053 * | ||||
|
Model 7—Housing Indoor Household Smoking |
NH White or Hispanic | 311 (71.3%) | 2.45 ± 1.95 | Reference | – | – | 9.6% ± 1.7% | Reference | – | – |
| NH Black | 122 (28.7%) | 3.93 ± 3.30 | +1.48 (+0.268) | +0.98 to +1.99 | <0.001 ** | 24.6% ± 3.9% | 3.1 | 1.8 to 5.4 | <0.001 ** | |
| Adjusted a,e | +1.30 (+0.234) | +0.79 to +1.80 | <0.001 ** | 3.3 | 1.6 to 6.4 | 0.001 ** | ||||
|
Model 8—Income Low Income |
NH White or Hispanic | 674 (81.1%) | 2.01 ± 1.93 | Reference | – | – | 6.2% ± 0.9% | Reference | – | – |
| NH Black | 157 (18.9%) | 2.96 ± 4.03 | +0.94 (+0.148) | +0.51 to +1.37 | <0.001 ** | 11.5% ± 2.6% | 2.0 | 1.1 to 3.5 | 0.025 * | |
| Adjusted a,f | +0.90 (+0.142) | +0.48 to +1.32 | <0.001 ** | 2.1 | 1.1 to 4.1 | 0.034 * | ||||
|
Model 9—Income Poverty |
NH White or Hispanic | 647 (74.5%) | 2.24 ± 2.07 | Reference | – | – | 7.1% ± 1.0% | Reference | – | – |
| NH Black | 221 (25.5%) | 3.53 ± 3.10 | +1.29 (+0.231) | +0.93 to +1.65 | <0.001 ** | 20.4% ± 2.7% | 3.3 | 2.1 to 5.2 | <0.001 ** | |
| Adjusted a,f | +1.22 (+0.220) | +0.89 to +1.58 | <0.001 ** | 4.1 | 2.3 to 7.0 | <0.001** | ||||
Covariates:a examined risk factors; survey years; binary gender; bodyweight; low birthweight; anemia; health insurance coverage; Medicaid/CHIP enrollment; federal Women, Infants, and Children (WIC) supplemental food program enrollment; use of water treatment devices; b age in months; c educational attainment less than 9th grade education; d housing built before 1960 or 1940; e number of cigarettes smoked inside the home per day (1 to 40 or more); f poverty-to-income ratios. Statistical significance: * p-value equal to 5% or less; ** p-value equal to 1% or less.