TABLE 2. Weighted geometric mean blood lead levels* in U.S. children aged 1–5 years, by selected sociodemographic characteristics — four National Health and Nutrition Examination Survey cycles, United States, 1999–2016.
| Characteristic | 1999–2002 |
2003–2006 |
2007–2010 |
2011–2016 |
||||
|---|---|---|---|---|---|---|---|---|
| No. | GM, μg/dL (95% CI) | No. | GM, μg/dL (95% CI) | No. | GM, μg/dL (95% CI) | No. | GM, μg/dL (95% CI) | |
|
Overall
|
1,621 |
1.95 (1.79–2.12) |
1,879 |
1.61 (1.52–1.71) |
1,653 |
1.33 (1.26–1.41) |
2,321 |
0.83 (0.78–0.88) |
|
Age group, yrs
| ||||||||
| 1–2 |
779 |
2.19 (2.01–2.39) |
919 |
1.81 (1.71–1.92) |
793 |
1.49 (1.39–1.59) |
1,024 |
0.93 (0.86–1.00) |
| 3–5 |
842 |
1.82 (1.64–2.01) |
960 |
1.48 (1.38–1.60) |
860 |
1.24 (1.15–1.33) |
1,297 |
0.77 (0.72–0.82) |
|
Sex
| ||||||||
| Male |
851 |
1.95 (1.77–2.14) |
951 |
1.61 (1.51–1.72) |
872 |
1.34 (1.25–1.43) |
1,213 |
0.86 (0.80–0.92) |
| Female |
770 |
1.95 (1.77–2.16) |
928 |
1.61 (1.49–1.73) |
781 |
1.32 (1.24–1.41) |
1,108 |
0.79 (0.74–0.85) |
|
Race/Ethnicity†
| ||||||||
| Black, non-Hispanic |
439 |
2.81 (2.56–3.09) |
530 |
2.43 (2.12–2.80) |
338 |
1.77 (1.62–1.93) |
608 |
1.07 (0.97–1.18) |
| Mexican American |
541 |
1.89 (1.75–2.03) |
611 |
1.57 (1.46–1.69) |
490 |
1.28 (1.17–1.39) |
526 |
0.78 (0.72–0.84) |
| White, non-Hispanic |
454 |
1.83 (1.60–2.09) |
535 |
1.44 (1.35–1.54) |
536 |
1.26 (1.14–1.39) |
563 |
0.79 (0.71–0.88) |
|
Income to poverty ratio§
| ||||||||
| <1.3 |
808 |
2.44 (2.24–2.66) |
936 |
2.01 (1.85–2.18) |
864 |
1.57 (1.48–1.67) |
1,149 |
0.97 (0.90–1.05) |
| ≥1.3 | 686 | 1.60 (1.45–1.77) | 857 | 1.39 (1.30–1.49) | 676 | 1.17 (1.08–1.27) | 997 | 0.72 (0.67–0.77) |
Abbreviations: CI = confidence interval; GM = geometric mean; NHANES = National Health and Nutrition Examination Survey.
* Weighted estimates derived from the observed data for the study population using NHANES-specified sampling weights. The GM blood lead levels in children aged 1–5 years have decreased over time.
† Data by race and Hispanic origin were limited to the three racial and Hispanic origin groups available across all survey cycles (non-Hispanic White, non-Hispanic Black, and Mexican American).
§ Computed as the total family income divided by the poverty threshold.